Add Liquid::Box for secure sandboxed template execution

Introduces Liquid::Box which wraps Ruby 4.0's Ruby::Box for secure
template execution. On Ruby < 4.0, provides a polyfill with security
warnings.

Key features:
- Detects Ruby::Box availability at load time
- Loads safe libraries (CGI, Base64, BigDecimal) into sandbox
- Neuters dangerous methods (file IO, process control, eval, etc.)
- Preserves user constants defined before lock!
- Provides setup_gem_load_paths! to enable gem requires in box

Security model: It is safe to expose side-effect-free, non-IO methods
that don't leak objects with dangerous methods. The sandbox blocks
capabilities, not data.

.github/dependabot.yaml

@@ -1,6 +0,0 @@
-version: 2
-updates:
-  - package-ecosystem: github-actions
-    directory: "/"
-    schedule:
-      interval: weekly

.github/workflows/liquid.yml

@@ -31,8 +31,8 @@ jobs:
           - { ruby: ruby-head, allowed-failure: false, rubyopt: "--yjit" }
     name: Test Ruby ${{ matrix.entry.ruby }}
     steps:
-      - uses: actions/checkout@f43a0e5ff2bd294095638e18286ca9a3d1956744 # v3.6.0
-      - uses: ruby/setup-ruby@dffc446db9ba5a0c4446edb5bca1c5c473a806c5 # v1.235.0
+      - uses: actions/checkout@v3
+      - uses: ruby/setup-ruby@v1
         with:
           ruby-version: ${{ matrix.entry.ruby }}
           bundler-cache: true
@@ -45,8 +45,8 @@ jobs:
   memory_profile:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@f43a0e5ff2bd294095638e18286ca9a3d1956744 # v3.6.0
-      - uses: ruby/setup-ruby@dffc446db9ba5a0c4446edb5bca1c5c473a806c5 # v1.235.0
+      - uses: actions/checkout@v3
+      - uses: ruby/setup-ruby@v1
         with:
           bundler-cache: true
       - run: bundle exec rake memory_profile:run

History.md

@@ -1,7 +1,6 @@
 # Liquid Change Log
 
-## 5.8.7
-* Expose body content in the `Doc` tag [James Meng]
+## 5.8.1 (unreleased)
 
 ## 5.8.1
 

lib/liquid.rb

@@ -89,3 +89,4 @@ require 'liquid/partial_cache'
 require 'liquid/usage'
 require 'liquid/registers'
 require 'liquid/template_factory'
+require 'liquid/box'

lib/liquid/box.rb

@@ -0,0 +1,493 @@
+# frozen_string_literal: true
+
+# Liquid::Box - Secure sandboxed execution environment for compiled Liquid templates
+#
+# On Ruby 4.0+, this uses the native Ruby::Box for true isolation.
+# On earlier Ruby versions, this provides a polyfill that WARNS about insecurity.
+#
+# == SECURITY WARNING
+#
+# The polyfill on Ruby < 4.0 provides NO REAL SECURITY. It's a compatibility shim
+# that allows code to run, but malicious templates could potentially escape.
+# Use Ruby 4.0+ in production for actual sandboxing.
+#
+# == Usage
+#
+#   template = Liquid::Template.parse("Hello {{ name }}!")
+#   compiled = template.compile_to_ruby
+#
+#   # compiled is a Liquid::CompiledTemplate which wraps a Box
+#   result = compiled.render({ "name" => "World" })
+#   # => "Hello World!"
+#
+#   # Access the generated Ruby code:
+#   puts compiled.source
+#
+
+module Liquid
+  # Check if we have Ruby 4.0's native Box AND it's enabled
+  # Ruby::Box may be defined but disabled (requires RUBY_BOX=1 env var before Ruby starts)
+  RUBY_BOX_AVAILABLE = begin
+    if defined?(Ruby::Box)
+      # Try to create a box to see if it's actually enabled
+      test_box = Ruby::Box.new
+      true
+    else
+      false
+    end
+  rescue RuntimeError => e
+    # Ruby::Box exists but is disabled
+    false
+  end
+
+  unless RUBY_BOX_AVAILABLE
+    # Warn once on load that we're using the insecure polyfill
+    warn "[Liquid::Box] WARNING: Ruby::Box not available or disabled. " \
+         "Using INSECURE polyfill. Compiled templates are NOT sandboxed! " \
+         "(Ruby 4.0+ with RUBY_BOX=1 required for secure execution)" if $VERBOSE
+  end
+
+  # Polyfill for Ruby::Box when not available (Ruby < 4.0)
+  # This provides the same API but NO SECURITY - it just evals code in the main environment.
+  module BoxPolyfill
+    class Box
+      def initialize
+        @constants = {}
+        @binding = TOPLEVEL_BINDING.dup
+      end
+
+      def eval(code)
+        ::Kernel.eval(code, @binding)
+      end
+
+      def const_get(name)
+        ::Object.const_get(name)
+      end
+    end
+  end
+
+  # Liquid::Box wraps either Ruby::Box (secure) or BoxPolyfill::Box (insecure)
+  #
+  # This provides a secure sandboxed environment for executing compiled Liquid templates.
+  # On Ruby 4.0+, templates run in true isolation with dangerous methods removed.
+  # On Ruby < 4.0, templates run without sandboxing (development/testing only).
+  #
+  class Box
+    attr_reader :box
+
+    class << self
+      # Returns true if we have real sandboxing (Ruby 4.0+)
+      def secure?
+        RUBY_BOX_AVAILABLE
+      end
+
+      # Create a pre-configured box for Liquid template execution.
+      # This is the recommended way to get a Box instance.
+      def create_for_liquid
+        box = new
+        box.load_liquid_runtime!
+        box.lock!
+        box
+      end
+    end
+
+    def initialize
+      @box = RUBY_BOX_AVAILABLE ? Ruby::Box.new : BoxPolyfill::Box.new
+      @locked = false
+      @user_constants = []
+      @warned_insecure = false
+    end
+
+    # Load code into the sandbox before locking.
+    # Use this to define filters, helpers, and the Liquid runtime.
+    def load_runtime(code)
+      raise "Cannot load runtime after lock!" if @locked
+      before = @box.eval("Object.constants")
+      @box.eval(code)
+      after = @box.eval("Object.constants")
+      @user_constants += (after - before).map(&:to_s)
+    end
+
+    # Load the standard Liquid runtime helpers (LR module).
+    # Call this before lock! to set up the execution environment.
+    # The runtime provides all helper methods that compiled templates use.
+    def load_liquid_runtime!
+      raise "Cannot load runtime after lock!" if @locked
+
+      if RUBY_BOX_AVAILABLE
+        # Add gem paths to box's load_path so it can find base64, bigdecimal, etc.
+        # These are safe, side-effect-free libs that only provide pure functions
+        setup_gem_load_paths!
+
+        # Load dependencies INTO the box - we need the actual libraries,
+        # not reimplementations, to handle all edge cases correctly
+        @box.require('cgi')
+        @box.require('base64')
+        @box.require('bigdecimal')
+        @box.require('bigdecimal/util')  # For String#to_d etc.
+
+        # Now load the runtime which captures method references from these
+        @box.require(RUNTIME_PATH)
+      else
+        # Polyfill: just require it normally
+        require 'cgi'
+        require 'base64'
+        require 'bigdecimal'
+        require 'bigdecimal/util'
+        require RUNTIME_PATH
+      end
+
+      # Track constants to preserve after lock
+      @user_constants << "LR"
+      @user_constants << "LiquidRuntime"
+      @user_constants << "CGI"
+      @user_constants << "Base64"
+      @user_constants << "BigDecimal"
+    end
+
+    # Add gem paths to the box's load_path so require works for gems
+    def setup_gem_load_paths!
+      return unless RUBY_BOX_AVAILABLE
+
+      # Find gem paths from the main environment's $LOAD_PATH
+      # and from Gem.path if available
+      gem_lib_paths = []
+
+      # Method 1: Find from $LOAD_PATH entries containing "gems"
+      $LOAD_PATH.each do |path|
+        gem_lib_paths << path if path.include?('/gems/')
+      end
+
+      # Method 2: Use Gem.path if available
+      if defined?(Gem) && Gem.respond_to?(:path)
+        Gem.path.each do |gem_path|
+          Dir.glob("#{gem_path}/gems/*/lib").each do |lib_path|
+            gem_lib_paths << lib_path
+          end
+        end
+      end
+
+      # Add unique paths to box's load_path
+      gem_lib_paths.uniq.each do |path|
+        @box.load_path << path unless @box.load_path.include?(path)
+      end
+    end
+
+    # Lock the sandbox. After this:
+    # - No more runtime can be loaded
+    # - Dangerous methods are removed (on Ruby 4.0+)
+    # - Templates can be compiled and executed
+    def lock!
+      return if @locked
+
+      if RUBY_BOX_AVAILABLE
+        apply_sandbox!
+      else
+        warn_insecure!
+      end
+
+      @locked = true
+    end
+
+    def locked?
+      @locked
+    end
+
+    # Returns true if this box provides real security (Ruby 4.0+)
+    def secure?
+      RUBY_BOX_AVAILABLE
+    end
+
+    # Evaluate code in the sandbox.
+    # Use this to compile templates into the sandbox.
+    def eval(code)
+      raise "Must call lock! before eval" unless @locked
+      warn_insecure! unless RUBY_BOX_AVAILABLE
+      @box.eval(code)
+    end
+
+    # Get a constant from the sandbox by name.
+    def const_get(name)
+      @box.const_get(name)
+    end
+
+    def [](name)
+      const_get(name)
+    end
+
+    private
+
+    def warn_insecure!
+      return if @warned_insecure
+      @warned_insecure = true
+
+      $stderr.puts <<~WARNING
+        ╔══════════════════════════════════════════════════════════════════════════════╗
+        ║ SECURITY WARNING: Liquid::Box running WITHOUT sandboxing                     ║
+        ║                                                                              ║
+        ║ Ruby::Box requires Ruby 4.0+. On earlier versions, compiled Liquid templates ║
+        ║ execute with FULL Ruby capabilities. This is NOT SECURE for untrusted input. ║
+        ║                                                                              ║
+        ║ For production use with untrusted templates, upgrade to Ruby 4.0+.           ║
+        ╚══════════════════════════════════════════════════════════════════════════════╝
+      WARNING
+    end
+
+    # Apply sandbox restrictions (Ruby 4.0+ only)
+    def apply_sandbox!
+      neuter_file_system!
+      neuter_process_control!
+      neuter_concurrency!
+      neuter_introspection!
+      neuter_serialization!
+      neuter_time!
+      neuter_environment!
+      neuter_kernel!
+      neuter_basic_object!
+      neuter_object!
+      neuter_main_singleton!
+      neuter_module!
+      cleanup_globals!
+      remove_dangerous_constants!
+    end
+
+    def neuter_file_system!
+      @box.eval(<<~'RUBY')
+        class << File
+          instance_methods(false).each { |m| undef_method(m) rescue nil }
+        end
+        class << IO
+          instance_methods(false).each { |m| undef_method(m) rescue nil }
+        end
+        class << Dir
+          instance_methods(false).each { |m| undef_method(m) rescue nil }
+        end
+        class IO
+          [:read, :write, :gets, :puts, :print, :readline, :readlines, :getc, :getbyte,
+           :sysread, :syswrite, :close, :eof, :eof?, :rewind, :seek].each do |m|
+            undef_method(m) rescue nil
+          end
+        end
+      RUBY
+    end
+
+    def neuter_process_control!
+      @box.eval(<<~'RUBY')
+        class << Process
+          instance_methods(false).each { |m| undef_method(m) rescue nil }
+        end
+        class << Signal
+          instance_methods(false).each { |m| undef_method(m) rescue nil }
+        end
+      RUBY
+    end
+
+    def neuter_concurrency!
+      @box.eval(<<~'RUBY')
+        class << Thread
+          [:new, :start, :fork, :kill, :exit, :pass, :stop, :main, :current, :list,
+           :abort_on_exception, :abort_on_exception=].each { |m| undef_method(m) rescue nil }
+        end
+        class << Fiber
+          [:new, :yield, :current].each { |m| undef_method(m) rescue nil }
+        end
+        if defined?(Ractor)
+          class << Ractor
+            instance_methods(false).each { |m| undef_method(m) rescue nil }
+          end
+        end
+      RUBY
+    end
+
+    def neuter_introspection!
+      @box.eval(<<~'RUBY')
+        class << ObjectSpace
+          instance_methods(false).each { |m| undef_method(m) rescue nil }
+        end
+        class << GC
+          instance_methods(false).each { |m| undef_method(m) rescue nil }
+        end
+        if defined?(RubyVM)
+          class << RubyVM
+            instance_methods(false).each { |m| undef_method(m) rescue nil }
+          end
+          if defined?(RubyVM::InstructionSequence)
+            class << RubyVM::InstructionSequence
+              instance_methods(false).each { |m| undef_method(m) rescue nil }
+            end
+          end
+        end
+        class << TracePoint
+          [:new, :stat, :trace].each { |m| undef_method(m) rescue nil }
+        end
+      RUBY
+    end
+
+    def neuter_serialization!
+      @box.eval(<<~'RUBY')
+        class << Marshal
+          [:dump, :load, :restore].each { |m| undef_method(m) rescue nil }
+        end
+      RUBY
+    end
+
+    def neuter_time!
+      # Time is neutered by default for security.
+      # Templates that need time should receive it via assigns.
+      @box.eval(<<~'RUBY')
+        class << Time
+          [:now, :new, :at, :mktime, :local, :utc, :gm].each { |m| undef_method(m) rescue nil }
+        end
+      RUBY
+    end
+
+    def neuter_environment!
+      @box.eval(<<~'RUBY')
+        ENV.clear rescue nil
+        class << ENV
+          instance_methods(false).each { |m| undef_method(m) rescue nil }
+        end
+      RUBY
+    end
+
+    def neuter_kernel!
+      @box.eval(<<~'RUBY')
+        module Kernel
+          [:eval, :`, :system, :exec, :spawn, :fork, :binding,
+           :open, :require, :require_relative, :load, :autoload, :autoload?,
+           :gets, :readline, :readlines, :select, :test,
+           :trap, :exit, :exit!, :abort, :at_exit, :syscall, :sleep,
+           :puts, :print, :printf, :putc, :p, :pp, :warn,
+           :caller, :caller_locations, :set_trace_func, :trace_var, :untrace_var,
+           :global_variables, :local_variables,
+           :gem, :gem_original_require, :Pathname,
+          ].each { |m| undef_method(m) rescue nil }
+        end
+
+        class << Kernel
+          [:eval, :`, :system, :exec, :spawn, :fork, :binding,
+           :open, :require, :require_relative, :load,
+           :puts, :print, :p, :pp, :warn,
+          ].each { |m| undef_method(m) rescue nil }
+        end
+      RUBY
+    end
+
+    def neuter_basic_object!
+      @box.eval(<<~'RUBY')
+        class BasicObject
+          undef_method(:instance_eval) rescue nil
+          undef_method(:instance_exec) rescue nil
+          undef_method(:__send__) rescue nil
+        end
+      RUBY
+    end
+
+    def neuter_object!
+      @box.eval(<<~'RUBY')
+        class Object
+          [:gem, :gem_original_require, :require, :require_relative, :load,
+           :display, :define_singleton_method,
+           :instance_variable_set, :remove_instance_variable,
+           :extend, :send, :public_send,
+          ].each { |m| undef_method(m) rescue nil }
+        end
+      RUBY
+    end
+
+    def neuter_main_singleton!
+      # 'using' is defined on main's singleton class, must remove before undef_method is gone
+      @box.eval(<<~'RUBY')
+        class << self
+          undef_method(:using) rescue nil
+        end
+      RUBY
+    end
+
+    def neuter_module!
+      @box.eval(<<~'RUBY')
+        class Module
+          undef_method(:refine) rescue nil
+          undef_method(:using) rescue nil
+          undef_method(:const_set) rescue nil
+          undef_method(:remove_const) rescue nil
+          undef_method(:include) rescue nil
+          undef_method(:prepend) rescue nil
+          undef_method(:extend) rescue nil
+          undef_method(:class_eval) rescue nil
+          undef_method(:module_eval) rescue nil
+          undef_method(:class_exec) rescue nil
+          undef_method(:module_exec) rescue nil
+          undef_method(:define_method) rescue nil
+          undef_method(:alias_method) rescue nil
+          undef_method(:module_function) rescue nil
+          undef_method(:prepend_features) rescue nil
+          undef_method(:append_features) rescue nil
+          undef_method(:extend_object) rescue nil
+          undef_method(:public) rescue nil
+          undef_method(:private) rescue nil
+          undef_method(:protected) rescue nil
+          undef_method(:attr) rescue nil
+          undef_method(:attr_reader) rescue nil
+          undef_method(:attr_writer) rescue nil
+          undef_method(:attr_accessor) rescue nil
+          # Remove escape hatches LAST
+          undef_method(:remove_method) rescue nil
+          undef_method(:undef_method) rescue nil
+          undef_method(:send) rescue nil
+          undef_method(:public_send) rescue nil
+        end
+
+        class Class
+          undef_method(:send) rescue nil
+          undef_method(:public_send) rescue nil
+        end
+      RUBY
+    end
+
+    def cleanup_globals!
+      @box.eval(<<~'RUBY')
+        $stdin = nil
+        $stdout = nil
+        $stderr = nil
+        $LOAD_PATH.clear rescue nil
+        $LOAD_PATH.freeze rescue nil
+        $LOADED_FEATURES.clear rescue nil
+        $LOADED_FEATURES.freeze rescue nil
+        ARGV.clear rescue nil
+        ARGV.freeze rescue nil
+      RUBY
+    end
+
+    def remove_dangerous_constants!
+      keep = %w[
+        BasicObject Object Module Class Kernel
+        String Integer Float Numeric Rational Complex
+        Array Hash Range Set
+        Symbol Regexp MatchData
+        TrueClass FalseClass NilClass
+        Proc Method UnboundMethod
+        Struct Data
+        Comparable Enumerable Enumerator
+        StandardError RuntimeError ArgumentError TypeError NameError
+        NoMethodError KeyError IndexError StopIteration FrozenError
+        ZeroDivisionError RangeError FloatDomainError LocalJumpError
+        Math Random
+        Exception SystemStackError
+      ] + @user_constants
+
+      @box.eval(<<~RUBY)
+        _keep = #{keep.inspect}
+        (Object.constants.map(&:to_s) - _keep).each do |c|
+          Object.send(:remove_const, c.to_sym) rescue nil
+        end
+        (Kernel.constants.map(&:to_s) - _keep).each do |c|
+          Kernel.send(:remove_const, c.to_sym) rescue nil
+        end
+      RUBY
+    end
+
+    # Path to the runtime file that gets loaded into the sandbox
+    RUNTIME_PATH = File.expand_path('compile/runtime.rb', __dir__)
+  end
+end

lib/liquid/compile.rb

@@ -0,0 +1,83 @@
+# frozen_string_literal: true
+
+# Liquid Ruby Compiler
+#
+# This module provides the ability to compile Liquid templates to pure Ruby code.
+# The compiled code can be eval'd to create a proc that renders the template
+# without needing the Liquid library at runtime.
+#
+# ## Usage
+#
+#   template = Liquid::Template.parse("Hello, {{ name }}!")
+#   ruby_code = template.compile_to_ruby
+#   render_proc = eval(ruby_code)
+#   result = render_proc.call({ "name" => "World" })
+#   # => "Hello, World!"
+#
+# ## Optimization Opportunities
+#
+# The compiled Ruby code has several significant advantages over interpreted Liquid:
+#
+# 1. **No Context Object**: Variables are extracted directly from the assigns hash
+#    and accessed without the Context abstraction layer.
+#
+# 2. **No Filter Invocation Overhead**: Filters are compiled to direct Ruby method
+#    calls rather than going through context.invoke().
+#
+# 3. **No Resource Limits Tracking**: The compiled code doesn't track render
+#    scores, write scores, or assign scores, eliminating per-node overhead.
+#
+# 4. **No Stack-based Scoping**: Ruby's native block scoping is used instead
+#    of manually managing scope stacks.
+#
+# 5. **Direct String Concatenation**: Output is built with direct << operations.
+#
+# 6. **Native Control Flow**: break/continue use Ruby's throw/catch mechanism.
+#
+# 7. **No to_liquid Calls**: Values are used directly without conversion.
+#
+# 8. **No Profiling Hooks**: No profiler overhead in the generated code.
+#
+# 9. **No Exception Rendering**: Errors propagate naturally.
+#
+# ## Limitations
+#
+# - {% render %} and {% include %} tags require runtime support
+# - Custom tags need explicit compiler implementations
+# - Custom filters need to be available at runtime
+#
+module Liquid
+  module Compile
+    autoload :CompiledTemplate, 'liquid/compile/compiled_template'
+    autoload :CompiledContext, 'liquid/compile/compiled_context'
+    autoload :CodeGenerator, 'liquid/compile/code_generator'
+    autoload :RubyCompiler, 'liquid/compile/ruby_compiler'
+    autoload :ExpressionCompiler, 'liquid/compile/expression_compiler'
+    autoload :FilterCompiler, 'liquid/compile/filter_compiler'
+    autoload :VariableCompiler, 'liquid/compile/variable_compiler'
+    autoload :BlockBodyCompiler, 'liquid/compile/block_body_compiler'
+    autoload :ConditionCompiler, 'liquid/compile/condition_compiler'
+    autoload :SourceMapper, 'liquid/compile/source_mapper'
+
+    module Tags
+      autoload :IfCompiler, 'liquid/compile/tags/if_compiler'
+      autoload :UnlessCompiler, 'liquid/compile/tags/unless_compiler'
+      autoload :CaseCompiler, 'liquid/compile/tags/case_compiler'
+      autoload :ForCompiler, 'liquid/compile/tags/for_compiler'
+      autoload :AssignCompiler, 'liquid/compile/tags/assign_compiler'
+      autoload :CaptureCompiler, 'liquid/compile/tags/capture_compiler'
+      autoload :CycleCompiler, 'liquid/compile/tags/cycle_compiler'
+      autoload :IncrementCompiler, 'liquid/compile/tags/increment_compiler'
+      autoload :DecrementCompiler, 'liquid/compile/tags/decrement_compiler'
+      autoload :RawCompiler, 'liquid/compile/tags/raw_compiler'
+      autoload :EchoCompiler, 'liquid/compile/tags/echo_compiler'
+      autoload :BreakCompiler, 'liquid/compile/tags/break_compiler'
+      autoload :ContinueCompiler, 'liquid/compile/tags/continue_compiler'
+      autoload :CommentCompiler, 'liquid/compile/tags/comment_compiler'
+      autoload :TableRowCompiler, 'liquid/compile/tags/tablerow_compiler'
+      autoload :RenderCompiler, 'liquid/compile/tags/render_compiler'
+      autoload :IncludeCompiler, 'liquid/compile/tags/include_compiler'
+      autoload :IfchangedCompiler, 'liquid/compile/tags/ifchanged_compiler'
+    end
+  end
+end

lib/liquid/compile/block_body_compiler.rb

@@ -0,0 +1,49 @@
+# frozen_string_literal: true
+
+module Liquid
+  module Compile
+    # BlockBodyCompiler compiles a BlockBody (a list of nodes) to Ruby code.
+    #
+    # A BlockBody contains:
+    # - String literals (text to output)
+    # - Variable expressions ({{ ... }})
+    # - Tags ({% ... %})
+    class BlockBodyCompiler
+      # Compile a BlockBody to Ruby code
+      # @param body [Liquid::BlockBody] The block body
+      # @param compiler [RubyCompiler] The main compiler instance
+      # @param code [CodeGenerator] The code generator
+      def self.compile(body, compiler, code)
+        return if body.nil?
+
+        nodelist = body.nodelist
+        return if nodelist.nil? || nodelist.empty?
+
+        nodelist.each do |node|
+          compile_node(node, compiler, code)
+        end
+      end
+
+      # Compile a single node
+      def self.compile_node(node, compiler, code)
+        case node
+        when String
+          compile_string(node, code)
+        when Variable
+          VariableCompiler.compile(node, compiler, code)
+        when Tag
+          compiler.send(:compile_tag, node, code)
+        else
+          raise CompileError, "Unknown node type in BlockBody: #{node.class}"
+        end
+      end
+
+      private
+
+      def self.compile_string(str, code)
+        return if str.empty?
+        code.line "__output__ << #{str.inspect}"
+      end
+    end
+  end
+end

lib/liquid/compile/code_generator.rb

@@ -0,0 +1,82 @@
+# frozen_string_literal: true
+
+module Liquid
+  module Compile
+    # CodeGenerator provides a clean interface for building Ruby code strings
+    # with proper indentation and formatting.
+    class CodeGenerator
+      INDENT_SIZE = 2
+
+      def initialize
+        @lines = []
+        @indent_level = 0
+      end
+
+      # Add a line of code at the current indentation level
+      # @param text [String] The code to add
+      def line(text)
+        @lines << ("  " * @indent_level) + text
+      end
+
+      # Add a blank line
+      def blank_line
+        @lines << ""
+      end
+
+      # Add multiple lines (useful for multi-line strings)
+      # @param text [String] Multi-line string to add
+      def lines(text)
+        text.each_line do |l|
+          line(l.chomp)
+        end
+      end
+
+      # Increase indentation for a block
+      def indent
+        @indent_level += 1
+        yield
+        @indent_level -= 1
+      end
+
+      # Get the current indentation string
+      def current_indent
+        "  " * @indent_level
+      end
+
+      # Add raw code without indentation adjustment
+      def raw(text)
+        @lines << text
+      end
+
+      # Convert to final Ruby code string
+      def to_s
+        @lines.join("\n")
+      end
+
+      # Generate an inline expression (doesn't add to lines, returns string)
+      # @param expr [String] The expression
+      # @return [String] The expression wrapped appropriately
+      def self.inline(expr)
+        expr
+      end
+
+      # Generate a string literal
+      # @param str [String] The string to escape
+      # @return [String] Ruby string literal
+      def self.string_literal(str)
+        str.inspect
+      end
+
+      # Generate a safe variable name from a Liquid variable name
+      # @param name [String] The Liquid variable name
+      # @return [String] A safe Ruby variable name
+      def self.safe_var_name(name)
+        # Replace invalid characters with underscores
+        safe = name.to_s.gsub(/[^a-zA-Z0-9_]/, '_')
+        # Ensure it starts with a letter or underscore
+        safe = "_#{safe}" if safe =~ /\A\d/
+        safe
+      end
+    end
+  end
+end

lib/liquid/compile/compiled_context.rb

@@ -0,0 +1,81 @@
+# frozen_string_literal: true
+
+module Liquid
+  module Compile
+    # CompiledContext is a lightweight context-like object for compiled templates.
+    #
+    # It duck-types to Liquid::Context well enough for Drops to work, providing:
+    # - Variable lookup via [] and find_variable
+    # - strict_variables flag
+    # - registers hash
+    # - evaluate method for expressions
+    #
+    # This allows Drops to access other variables and use context features
+    # while still running in compiled mode.
+    class CompiledContext
+      attr_reader :assigns, :registers
+      attr_accessor :strict_variables, :strict_filters
+
+      def initialize(assigns, registers: {}, strict_variables: false, strict_filters: false)
+        @assigns = assigns
+        @registers = registers.is_a?(Liquid::Registers) ? registers : Liquid::Registers.new(registers)
+        @strict_variables = strict_variables
+        @strict_filters = strict_filters
+      end
+
+      # Variable lookup - used by Drops to access other variables
+      def [](key)
+        @assigns[key.to_s]
+      end
+
+      # Find a variable by name
+      def find_variable(key)
+        result = @assigns[key.to_s]
+        result = result.to_liquid if result.respond_to?(:to_liquid)
+        result.context = self if result.respond_to?(:context=)
+        result
+      end
+
+      # Evaluate an expression (for Drops that need to evaluate sub-expressions)
+      def evaluate(expr)
+        case expr
+        when String, Integer, Float, TrueClass, FalseClass, NilClass
+          expr
+        when Liquid::VariableLookup
+          expr.evaluate(self)
+        else
+          expr
+        end
+      end
+
+      # Lookup and evaluate - handles Procs in assigns
+      def lookup_and_evaluate(obj, key)
+        value = obj[key]
+        value = value.call(self) if value.is_a?(Proc)
+        value
+      end
+
+      # Handle errors (simplified - just return message)
+      def handle_error(error, _line_number = nil)
+        error.message
+      end
+
+      # Check if execution should be interrupted
+      def interrupt?
+        false
+      end
+
+      # Stub for resource limits (no-op in compiled mode)
+      def resource_limits
+        @resource_limits ||= ResourceLimitStub.new
+      end
+    end
+
+    # Stub for resource limits in compiled mode
+    class ResourceLimitStub
+      def increment_render_score(_score); end
+      def increment_write_score(_output); end
+      def reached?; false; end
+    end
+  end
+end

lib/liquid/compile/compiled_template.rb

@@ -0,0 +1,85 @@
+# frozen_string_literal: true
+
+module Liquid
+  module Compile
+    # Represents a compiled Liquid template ready for execution.
+    #
+    # Contains the Ruby source code and any external tags/filters that need to be
+    # passed to the generated lambda at runtime.
+    #
+    # Usage:
+    #   compiled = template.compile_to_ruby
+    #   result = compiled.call({ "name" => "World" })
+    #
+    #   # With custom filters:
+    #   compiled.filter_handler = MyFilterModule
+    #   result = compiled.call({ "name" => "World" })
+    #
+    class CompiledTemplate
+      attr_reader :code, :external_tags
+      attr_accessor :filter_handler
+
+      # @param code [String] The generated Ruby code
+      # @param external_tags [Hash] Map of variable names to Tag objects for runtime delegation
+      # @param has_external_filters [Boolean] Whether external filters are used
+      def initialize(code, external_tags = {}, has_external_filters = false)
+        @code = code
+        @external_tags = external_tags
+        @has_external_filters = has_external_filters
+        @filter_handler = nil
+        @proc = nil
+      end
+
+      # Returns true if this template has external tags that need runtime delegation
+      def has_external_tags?
+        !@external_tags.empty?
+      end
+
+      # Returns true if this template uses external filters
+      def has_external_filters?
+        @has_external_filters
+      end
+
+      # Returns the compiled proc, caching it after first compilation
+      def to_proc
+        @proc ||= eval(@code)
+      end
+
+      # Execute the compiled template with the given assigns
+      # @param assigns [Hash] The variable assignments
+      # @param filter_handler [Object] Optional filter handler to override the default
+      # @param registers [Hash] Optional registers for context
+      # @param strict_variables [Boolean] Raise on undefined variables
+      # @param strict_filters [Boolean] Raise on undefined filters
+      # @return [String] The rendered output
+      def call(assigns = {}, filter_handler: nil, registers: {}, strict_variables: false, strict_filters: false)
+        proc = to_proc
+        handler = filter_handler || @filter_handler
+
+        # Create a context for Drop support
+        context = CompiledContext.new(
+          assigns,
+          registers: registers,
+          strict_variables: strict_variables,
+          strict_filters: strict_filters
+        )
+
+        # Build arguments based on what the lambda expects
+        args = [assigns]
+        args << @external_tags if has_external_tags?
+        args << handler if has_external_filters?
+        args << context  # Always pass context as last arg
+
+        proc.call(*args)
+      end
+
+      # Returns the Ruby code as a string
+      def to_s
+        @code
+      end
+    end
+  end
+
+  # Make CompiledTemplate available at the top level for convenience
+  CompiledTemplate = Compile::CompiledTemplate
+end

lib/liquid/compile/condition_compiler.rb

@@ -0,0 +1,125 @@
+# frozen_string_literal: true
+
+module Liquid
+  module Compile
+    # ConditionCompiler compiles Liquid conditions to Ruby boolean expressions.
+    #
+    # Handles:
+    # - Simple truthiness: {% if variable %}
+    # - Comparisons: {% if a == b %}, {% if a > b %}
+    # - Logical operators: {% if a and b %}, {% if a or b %}
+    # - Special checks: {% if a == blank %}, {% if a == empty %}
+    class ConditionCompiler
+      # Operator mappings from Liquid to Ruby
+      OPERATORS = {
+        '==' => '==',
+        '!=' => '!=',
+        '<>' => '!=',
+        '<' => '<',
+        '>' => '>',
+        '<=' => '<=',
+        '>=' => '>=',
+        'contains' => :contains,
+      }.freeze
+
+      # Compile a Condition to a Ruby boolean expression
+      # @param condition [Liquid::Condition] The condition
+      # @param compiler [RubyCompiler] The main compiler instance
+      # @return [String] Ruby code expression that evaluates to true/false
+      def self.compile(condition, compiler)
+        if condition.is_a?(ElseCondition)
+          return "true"
+        end
+
+        compile_condition_chain(condition, compiler)
+      end
+
+      private
+
+      def self.compile_condition_chain(condition, compiler)
+        # Compile the current condition
+        current = compile_single_condition(condition, compiler)
+
+        # Check for chained conditions (and/or)
+        if condition.child_condition
+          child = compile_condition_chain(condition.child_condition, compiler)
+          child_relation = condition.send(:child_relation)
+
+          case child_relation
+          when :and
+            "(#{current} && #{child})"
+          when :or
+            "(#{current} || #{child})"
+          else
+            current
+          end
+        else
+          current
+        end
+      end
+
+      def self.compile_single_condition(condition, compiler)
+        left = condition.left
+        op = condition.operator
+        right = condition.right
+
+        # If no operator, just check truthiness
+        if op.nil?
+          left_expr = ExpressionCompiler.compile(left, compiler)
+          return "__truthy__(#{left_expr})"
+        end
+
+        # Compile left and right expressions
+        left_expr = compile_condition_value(left, compiler)
+        right_expr = compile_condition_value(right, compiler)
+
+        # Handle special operators
+        case OPERATORS[op]
+        when :contains
+          compile_contains(left_expr, right_expr, compiler)
+        when '=='
+          compile_equality(left, right, left_expr, right_expr, compiler)
+        when '!='
+          "!(#{compile_equality(left, right, left_expr, right_expr, compiler)})"
+        else
+          # Standard comparison
+          ruby_op = OPERATORS[op] || op
+          "(#{left_expr} #{ruby_op} #{right_expr} rescue false)"
+        end
+      end
+
+      def self.compile_condition_value(expr, compiler)
+        if expr.is_a?(Condition::MethodLiteral)
+          # For blank/empty checks, we return a special marker
+          # The equality handler will deal with this
+          ":__method_literal_#{expr.method_name}__"
+        else
+          ExpressionCompiler.compile(expr, compiler)
+        end
+      end
+
+      def self.compile_equality(left, right, left_expr, right_expr, compiler)
+        # Handle blank/empty method literals
+        if left.is_a?(Condition::MethodLiteral)
+          method_name = left.method_name
+          "(#{right_expr}.respond_to?(:#{method_name}) ? #{right_expr}.#{method_name} : nil)"
+        elsif right.is_a?(Condition::MethodLiteral)
+          method_name = right.method_name
+          "(#{left_expr}.respond_to?(:#{method_name}) ? #{left_expr}.#{method_name} : nil)"
+        else
+          "(#{left_expr} == #{right_expr})"
+        end
+      end
+
+      def self.compile_contains(left_expr, right_expr, compiler)
+        # The contains operator checks if left includes right
+        # For strings, right is converted to a string
+        "(lambda { |left, right| " \
+          "return false if left.nil? || right.nil? || !left.respond_to?(:include?); " \
+          "right = right.to_s if left.is_a?(String); " \
+          "left.include?(right) rescue false " \
+          "}.call(#{left_expr}, #{right_expr}))"
+      end
+    end
+  end
+end

lib/liquid/compile/expression_compiler.rb

@@ -0,0 +1,115 @@
+# frozen_string_literal: true
+
+module Liquid
+  module Compile
+    # ExpressionCompiler compiles Liquid expressions to Ruby code.
+    #
+    # Expressions include:
+    # - Literals: nil, true, false, strings, numbers
+    # - Variable lookups: foo, foo.bar, foo[0], foo["key"]
+    # - Ranges: (1..10), (start..end)
+    class ExpressionCompiler
+      # Compile an expression to a Ruby code string
+      # @param expr [Object] The parsed expression
+      # @param compiler [RubyCompiler] The main compiler instance
+      # @return [String] Ruby code that evaluates to the expression value
+      def self.compile(expr, compiler)
+        case expr
+        when nil
+          "nil"
+        when true
+          "true"
+        when false
+          "false"
+        when String
+          expr.inspect
+        when Integer, Float
+          expr.inspect
+        when Range
+          "(#{expr.begin.inspect}..#{expr.end.inspect})"
+        when VariableLookup
+          compile_variable_lookup(expr, compiler)
+        when RangeLookup
+          compile_range_lookup(expr, compiler)
+        when Condition::MethodLiteral
+          # Handle blank/empty method literals
+          compile_method_literal(expr, compiler)
+        else
+          raise CompileError, "Unknown expression type: #{expr.class} (#{expr.inspect})"
+        end
+      end
+
+      # Compile a variable lookup expression
+      # @param lookup [VariableLookup] The variable lookup
+      # @param compiler [RubyCompiler] The main compiler instance
+      # @return [String] Ruby code that evaluates to the variable value
+      def self.compile_variable_lookup(lookup, compiler)
+        # Start with the base variable
+        name = lookup.name
+
+        # Handle dynamic name (expression in brackets)
+        base = if name.is_a?(VariableLookup) || name.is_a?(RangeLookup)
+          # Dynamic name like [expr].foo
+          "assigns[#{compile(name, compiler)}]"
+        elsif name.is_a?(String)
+          "assigns[#{name.inspect}]"
+        elsif name.is_a?(Integer)
+          "assigns[#{name.inspect}]"
+        else
+          compile(name, compiler)
+        end
+
+        # Apply each lookup in the chain
+        lookup.lookups.each_with_index do |key, index|
+          if key.is_a?(VariableLookup) || key.is_a?(RangeLookup)
+            # Dynamic key like foo[expr]
+            base = "__lookup__.call(#{base}, #{compile(key, compiler)})"
+          elsif key.is_a?(Integer)
+            # Numeric index like foo[0]
+            base = "__lookup__.call(#{base}, #{key})"
+          elsif key.is_a?(String)
+            # Always use __lookup__ which tries key access first,
+            # then falls back to method call for command methods (first, last, size)
+            base = "__lookup__.call(#{base}, #{key.inspect})"
+          else
+            base = "__lookup__.call(#{base}, #{compile(key, compiler)})"
+          end
+        end
+
+        base
+      end
+
+      # Compile a range lookup expression
+      # @param range [RangeLookup] The range lookup
+      # @param compiler [RubyCompiler] The main compiler instance
+      # @return [String] Ruby code that evaluates to the range
+      def self.compile_range_lookup(range, compiler)
+        start_expr = compile(range.start_obj, compiler)
+        end_expr = compile(range.end_obj, compiler)
+
+        # Convert to integers and create range
+        "(__to_integer__(#{start_expr})...__to_integer__(#{end_expr})).to_a"
+      end
+
+      # Compile a method literal (blank/empty)
+      def self.compile_method_literal(literal, compiler)
+        # These are used in conditions like `if foo == blank`
+        # They represent special method calls
+        literal.to_s.inspect
+      end
+
+      # Compile an expression for use in a condition
+      # @param expr [Object] The expression
+      # @param compiler [RubyCompiler] The main compiler
+      # @return [String] Ruby code for the condition value
+      def self.compile_for_condition(expr, compiler)
+        if expr.is_a?(Condition::MethodLiteral)
+          # Return the method name symbol for special handling
+          ":#{expr.method_name}"
+        else
+          compile(expr, compiler)
+        end
+      end
+    end
+  end
+end

lib/liquid/compile/filter_compiler.rb

@@ -0,0 +1,233 @@
+# frozen_string_literal: true
+
+module Liquid
+  module Compile
+    # FilterCompiler compiles Liquid filter chains to Ruby code.
+    #
+    # Filters are applied in sequence: {{ value | filter1: arg1 | filter2: arg2 }}
+    # becomes a chain of method calls on the value.
+    class FilterCompiler
+      # Standard filters that map directly to Ruby methods or simple expressions
+      SIMPLE_FILTERS = {
+        'size' => ->(input, _args, _kwargs, _compiler) { "(#{input}.respond_to?(:size) ? #{input}.size : 0)" },
+        'downcase' => ->(input, _args, _kwargs, _compiler) { "__to_s__(#{input}).downcase" },
+        'upcase' => ->(input, _args, _kwargs, _compiler) { "__to_s__(#{input}).upcase" },
+        'capitalize' => ->(input, _args, _kwargs, _compiler) { "__to_s__(#{input}).capitalize" },
+        'strip' => ->(input, _args, _kwargs, _compiler) { "__to_s__(#{input}).strip" },
+        'lstrip' => ->(input, _args, _kwargs, _compiler) { "__to_s__(#{input}).lstrip" },
+        'rstrip' => ->(input, _args, _kwargs, _compiler) { "__to_s__(#{input}).rstrip" },
+        'reverse' => ->(input, _args, _kwargs, _compiler) { "(#{input}.is_a?(Array) ? #{input}.reverse : __to_s__(#{input}).reverse)" },
+        'first' => ->(input, _args, _kwargs, _compiler) { "(#{input}.respond_to?(:first) ? #{input}.first : nil)" },
+        'last' => ->(input, _args, _kwargs, _compiler) { "(#{input}.respond_to?(:last) ? #{input}.last : nil)" },
+        'uniq' => ->(input, _args, _kwargs, _compiler) { "(#{input}.respond_to?(:uniq) ? #{input}.uniq : #{input})" },
+        'compact' => ->(input, _args, _kwargs, _compiler) { "(#{input}.respond_to?(:compact) ? #{input}.compact : #{input})" },
+        'flatten' => ->(input, _args, _kwargs, _compiler) { "(#{input}.respond_to?(:flatten) ? #{input}.flatten : #{input})" },
+        'sort' => ->(input, _args, _kwargs, _compiler) { "(#{input}.respond_to?(:sort) ? #{input}.sort : #{input})" },
+        'abs' => ->(input, _args, _kwargs, _compiler) { "__to_number__(#{input}).abs" },
+        'ceil' => ->(input, _args, _kwargs, _compiler) { "__to_number__(#{input}).ceil.to_i" },
+        'floor' => ->(input, _args, _kwargs, _compiler) { "__to_number__(#{input}).floor.to_i" },
+        'escape' => ->(input, _args, _kwargs, _compiler) { "(#{input}.nil? ? nil : CGI.escapeHTML(__to_s__(#{input})))" },
+        'h' => ->(input, _args, _kwargs, _compiler) { "(#{input}.nil? ? nil : CGI.escapeHTML(__to_s__(#{input})))" },
+        'url_encode' => ->(input, _args, _kwargs, _compiler) { "(#{input}.nil? ? nil : CGI.escape(__to_s__(#{input})))" },
+        'url_decode' => ->(input, _args, _kwargs, _compiler) { "(#{input}.nil? ? nil : CGI.unescape(__to_s__(#{input})))" },
+        'base64_encode' => ->(input, _args, _kwargs, _compiler) { "Base64.strict_encode64(__to_s__(#{input}))" },
+        'base64_decode' => ->(input, _args, _kwargs, _compiler) { "Base64.strict_decode64(__to_s__(#{input}))" },
+        'base64_url_safe_encode' => ->(input, _args, _kwargs, _compiler) { "Base64.urlsafe_encode64(__to_s__(#{input}))" },
+        'base64_url_safe_decode' => ->(input, _args, _kwargs, _compiler) { "Base64.urlsafe_decode64(__to_s__(#{input}))" },
+        'strip_html' => ->(input, _args, _kwargs, _compiler) {
+          "__to_s__(#{input}).gsub(%r{<script.*?</script>|<!--.*?-->|<style.*?</style>}m, '').gsub(/<.*?>/m, '')"
+        },
+        'strip_newlines' => ->(input, _args, _kwargs, _compiler) { "__to_s__(#{input}).gsub(/\\r?\\n/, '')" },
+        'newline_to_br' => ->(input, _args, _kwargs, _compiler) { "__to_s__(#{input}).gsub(/\\r?\\n/, \"<br />\\n\")" },
+      }.freeze
+
+      # Filters with arguments that need special handling
+      PARAMETERIZED_FILTERS = {
+        'append' => ->(input, args, _kwargs, compiler) {
+          arg = compile_arg(args[0], compiler)
+          "__to_s__(#{input}) + __to_s__(#{arg})"
+        },
+        'prepend' => ->(input, args, _kwargs, compiler) {
+          arg = compile_arg(args[0], compiler)
+          "__to_s__(#{arg}) + __to_s__(#{input})"
+        },
+        'plus' => ->(input, args, _kwargs, compiler) {
+          arg = compile_arg(args[0], compiler)
+          "(__to_number__(#{input}) + __to_number__(#{arg}))"
+        },
+        'minus' => ->(input, args, _kwargs, compiler) {
+          arg = compile_arg(args[0], compiler)
+          "(__to_number__(#{input}) - __to_number__(#{arg}))"
+        },
+        'times' => ->(input, args, _kwargs, compiler) {
+          arg = compile_arg(args[0], compiler)
+          "(__to_number__(#{input}) * __to_number__(#{arg}))"
+        },
+        'divided_by' => ->(input, args, _kwargs, compiler) {
+          arg = compile_arg(args[0], compiler)
+          "(__to_number__(#{input}) / __to_number__(#{arg}))"
+        },
+        'modulo' => ->(input, args, _kwargs, compiler) {
+          arg = compile_arg(args[0], compiler)
+          "(__to_number__(#{input}) % __to_number__(#{arg}))"
+        },
+        'round' => ->(input, args, _kwargs, compiler) {
+          if args.empty?
+            "__to_number__(#{input}).round.to_i"
+          else
+            arg = compile_arg(args[0], compiler)
+            "__to_number__(#{input}).round(__to_number__(#{arg}))"
+          end
+        },
+        'at_least' => ->(input, args, _kwargs, compiler) {
+          arg = compile_arg(args[0], compiler)
+          "[__to_number__(#{input}), __to_number__(#{arg})].max"
+        },
+        'at_most' => ->(input, args, _kwargs, compiler) {
+          arg = compile_arg(args[0], compiler)
+          "[__to_number__(#{input}), __to_number__(#{arg})].min"
+        },
+        'default' => ->(input, args, kwargs, compiler) {
+          default_val = args.empty? ? "''" : compile_arg(args[0], compiler)
+          allow_false = kwargs && kwargs['allow_false'] ? compile_arg(kwargs['allow_false'], compiler) : 'false'
+          "(if #{allow_false} then (#{input}.nil? || (#{input}.respond_to?(:empty?) && #{input}.empty?)) else (!__truthy__(#{input}) || (#{input}.respond_to?(:empty?) && #{input}.empty?)) end) ? #{default_val} : #{input}"
+        },
+        'split' => ->(input, args, _kwargs, compiler) {
+          pattern = args.empty? ? "' '" : compile_arg(args[0], compiler)
+          "__to_s__(#{input}).split(__to_s__(#{pattern}))"
+        },
+        'join' => ->(input, args, _kwargs, compiler) {
+          glue = args.empty? ? "' '" : compile_arg(args[0], compiler)
+          "(#{input}.is_a?(Array) ? #{input}.map { |i| __to_s__(i) }.join(__to_s__(#{glue})) : __to_s__(#{input}))"
+        },
+        'replace' => ->(input, args, _kwargs, compiler) {
+          string = compile_arg(args[0], compiler)
+          replacement = args.length > 1 ? compile_arg(args[1], compiler) : "''"
+          "__to_s__(#{input}).gsub(__to_s__(#{string}), __to_s__(#{replacement}))"
+        },
+        'replace_first' => ->(input, args, _kwargs, compiler) {
+          string = compile_arg(args[0], compiler)
+          replacement = args.length > 1 ? compile_arg(args[1], compiler) : "''"
+          "__to_s__(#{input}).sub(__to_s__(#{string}), __to_s__(#{replacement}))"
+        },
+        'remove' => ->(input, args, _kwargs, compiler) {
+          string = compile_arg(args[0], compiler)
+          "__to_s__(#{input}).gsub(__to_s__(#{string}), '')"
+        },
+        'remove_first' => ->(input, args, _kwargs, compiler) {
+          string = compile_arg(args[0], compiler)
+          "__to_s__(#{input}).sub(__to_s__(#{string}), '')"
+        },
+        'truncate' => ->(input, args, _kwargs, compiler) {
+          length = args.empty? ? "50" : compile_arg(args[0], compiler)
+          ellipsis = args.length > 1 ? compile_arg(args[1], compiler) : "'...'"
+          var = compiler.generate_var_name("trunc")
+          "(lambda { |#{var}_input, #{var}_len, #{var}_ell| #{var}_str = __to_s__(#{var}_input); #{var}_ell_str = __to_s__(#{var}_ell); #{var}_l = [#{var}_len.to_i - #{var}_ell_str.length, 0].max; #{var}_str.length > #{var}_len.to_i ? #{var}_str[0, #{var}_l] + #{var}_ell_str : #{var}_str }).call(#{input}, #{length}, #{ellipsis})"
+        },
+        'truncatewords' => ->(input, args, _kwargs, compiler) {
+          words = args.empty? ? "15" : compile_arg(args[0], compiler)
+          ellipsis = args.length > 1 ? compile_arg(args[1], compiler) : "'...'"
+          "(lambda { |input, num_words, ell| words = __to_s__(input).split(' ', [num_words.to_i, 1].max + 1); words.length > [num_words.to_i, 1].max ? words[0, [num_words.to_i, 1].max].join(' ') + __to_s__(ell) : input.to_s }).call(#{input}, #{words}, #{ellipsis})"
+        },
+        'slice' => ->(input, args, _kwargs, compiler) {
+          offset = compile_arg(args[0], compiler)
+          length = args.length > 1 ? compile_arg(args[1], compiler) : "1"
+          "(#{input}.is_a?(Array) ? (#{input}.slice(__to_integer__(#{offset}), __to_integer__(#{length})) || []) : (__to_s__(#{input}).slice(__to_integer__(#{offset}), __to_integer__(#{length})) || ''))"
+        },
+        'map' => ->(input, args, _kwargs, compiler) {
+          property = compile_arg(args[0], compiler)
+          "(#{input}.is_a?(Array) ? #{input}.map { |item| item.respond_to?(:[]) ? item[#{property}] : nil } : [])"
+        },
+        'where' => ->(input, args, _kwargs, compiler) {
+          property = compile_arg(args[0], compiler)
+          if args.length > 1
+            target = compile_arg(args[1], compiler)
+            "(#{input}.is_a?(Array) ? #{input}.select { |item| item.respond_to?(:[]) && item[#{property}] == #{target} } : [])"
+          else
+            "(#{input}.is_a?(Array) ? #{input}.select { |item| item.respond_to?(:[]) && __truthy__(item[#{property}]) } : [])"
+          end
+        },
+        'reject' => ->(input, args, _kwargs, compiler) {
+          property = compile_arg(args[0], compiler)
+          if args.length > 1
+            target = compile_arg(args[1], compiler)
+            "(#{input}.is_a?(Array) ? #{input}.reject { |item| item.respond_to?(:[]) && item[#{property}] == #{target} } : [])"
+          else
+            "(#{input}.is_a?(Array) ? #{input}.reject { |item| item.respond_to?(:[]) && __truthy__(item[#{property}]) } : [])"
+          end
+        },
+        'concat' => ->(input, args, _kwargs, compiler) {
+          arr = compile_arg(args[0], compiler)
+          "(#{input}.is_a?(Array) ? #{input} + (#{arr}.respond_to?(:to_ary) ? #{arr}.to_ary : []) : [])"
+        },
+        'sort_natural' => ->(input, args, _kwargs, compiler) {
+          if args.empty?
+            "(#{input}.is_a?(Array) ? #{input}.sort_by { |a| a.to_s.downcase } : #{input})"
+          else
+            property = compile_arg(args[0], compiler)
+            "(#{input}.is_a?(Array) ? #{input}.sort_by { |a| a.respond_to?(:[]) ? a[#{property}].to_s.downcase : '' } : #{input})"
+          end
+        },
+        'date' => ->(input, args, _kwargs, compiler) {
+          format = compile_arg(args[0], compiler)
+          # This is a simplified version - full date parsing is complex
+          "(lambda { |input, fmt| return input if fmt.to_s.empty?; d = case input; when Time, Date, DateTime then input; when 'now', 'today' then Time.now; when /\\A\\d+\\z/, Integer then Time.at(input.to_i); when String then (Time.parse(input) rescue input); else input; end; d.respond_to?(:strftime) ? d.strftime(fmt.to_s) : input }.call(#{input}, #{format}))"
+        },
+        'escape_once' => ->(input, _args, _kwargs, _compiler) {
+          "__to_s__(#{input}).gsub(/[\"><']|&(?!([a-zA-Z]+|(#\\d+));)/) { |c| {'&'=>'&amp;', '>'=>'&gt;', '<'=>'&lt;', '\"'=>'&quot;', \"'\"=>'&#39;'}[c] || c }"
+        },
+      }.freeze
+
+      # Compile a filter chain
+      # @param input_expr [String] Ruby expression for the input value
+      # @param filters [Array] Array of filter definitions [name, args, kwargs]
+      # @param compiler [RubyCompiler] The main compiler instance
+      # @return [String] Ruby code that applies all filters
+      def self.compile(input_expr, filters, compiler)
+        result = input_expr
+
+        filters.each do |filter_name, filter_args, filter_kwargs|
+          result = compile_filter(result, filter_name, filter_args || [], filter_kwargs, compiler)
+        end
+
+        result
+      end
+
+      # Compile a single filter application
+      def self.compile_filter(input, name, args, kwargs, compiler)
+        if SIMPLE_FILTERS.key?(name)
+          SIMPLE_FILTERS[name].call(input, args, kwargs, compiler)
+        elsif PARAMETERIZED_FILTERS.key?(name)
+          PARAMETERIZED_FILTERS[name].call(input, args, kwargs, compiler)
+        else
+          # Fall back to a generic filter call
+          compile_generic_filter(input, name, args, kwargs, compiler)
+        end
+      end
+
+      # Compile a filter that's not built-in
+      # Uses __call_filter__ helper which must be provided by the runtime
+      def self.compile_generic_filter(input, name, args, kwargs, compiler)
+        # Mark that we're using external filters
+        compiler.register_external_filter
+
+        compiled_args = args.map { |arg| compile_arg(arg, compiler) }
+
+        if kwargs && !kwargs.empty?
+          kwargs_hash = kwargs.map { |k, v| "#{k.inspect} => #{compile_arg(v, compiler)}" }.join(", ")
+          compiled_args << "{ #{kwargs_hash} }"
+        end
+
+        args_str = compiled_args.empty? ? "[]" : "[#{compiled_args.join(', ')}]"
+
+        # Call through the filter helper which delegates to registered filters
+        "__call_filter__.call(#{name.inspect}, #{input}, #{args_str})"
+      end
+
+      # Compile a filter argument
+      def self.compile_arg(arg, compiler)
+        ExpressionCompiler.compile(arg, compiler)
+      end
+    end
+  end
+end

lib/liquid/compile/ruby_compiler.rb

@@ -0,0 +1,534 @@
+# frozen_string_literal: true
+
+module Liquid
+  module Compile
+    # RubyCompiler transforms a parsed Liquid template into pure Ruby code.
+    #
+    # The compiled code is a string that can be eval'd to create a proc/lambda
+    # that takes an assigns hash and returns the rendered output string.
+    #
+    # ## Optimization Opportunities
+    #
+    # The compiled Ruby code has several significant advantages over interpreted Liquid:
+    #
+    # 1. **No Context Object**: Instead of using a Context for variable lookups,
+    #    variables are extracted directly from the assigns hash and stored in
+    #    local Ruby variables. This eliminates hash lookups on every access.
+    #
+    # 2. **No Filter Invocation Overhead**: Filters are compiled to direct Ruby
+    #    method calls rather than going through context.invoke().
+    #
+    # 3. **No Resource Limits Tracking**: The compiled code doesn't track render
+    #    scores, write scores, or assign scores, eliminating per-node overhead.
+    #
+    # 4. **No Stack-based Scoping**: Ruby's native block scoping is used instead
+    #    of manually managing scope stacks with push/pop operations.
+    #
+    # 5. **Direct String Concatenation**: Output is built with direct << operations
+    #    rather than through render_to_output_buffer abstractions.
+    #
+    # 6. **Native Control Flow**: break/continue become Ruby's break/next,
+    #    eliminating interrupt objects and checks.
+    #
+    # 7. **No to_liquid Calls**: Values are used directly without conversion.
+    #
+    # 8. **Potential for Constant Folding**: Expressions with only literals
+    #    could be evaluated at compile time (future enhancement).
+    #
+    # 9. **Potential for Dead Code Elimination**: Unreachable branches like
+    #    `{% if false %}` could be removed (future enhancement).
+    #
+    # 10. **No Profiling Hooks**: No profiler overhead in the generated code.
+    #
+    # 11. **No Exception Rendering**: Errors propagate naturally rather than
+    #     being caught and rendered inline.
+    #
+    # ## Usage
+    #
+    #   template = Liquid::Template.parse("Hello, {{ name }}!")
+    #   ruby_code = template.compile_to_ruby
+    #   render_proc = eval(ruby_code)
+    #   result = render_proc.call({ "name" => "World" })
+    #   # => "Hello, World!"
+    #
+    class RubyCompiler
+      attr_reader :template, :options
+
+      # @param template [Liquid::Template] The parsed template to compile
+      # @param options [Hash] Compilation options
+      # @option options [Boolean] :strict_variables Raise on undefined variables (default: false)
+      # @option options [Boolean] :include_filters Include filter helper methods (default: true)
+      # @option options [Boolean] :debug Emit source comments for debugging (default: false)
+      # @option options [Object] :file_system File system for loading partials (default: template's environment)
+      def initialize(template, options = {})
+        @template = template
+        @options = {
+          strict_variables: false,
+          include_filters: true,
+          debug: false,
+          file_system: nil,
+        }.merge(options)
+        @var_counter = 0
+        @partials = {}        # Registered partials: name => method_name
+        @partial_sources = {} # Partial sources: name => source code
+        @partial_counter = 0
+        @external_tags = {}   # External tags: var_name => tag object
+        @external_tag_counter = 0
+        @has_external_filters = false  # Whether we need the filter helper
+      end
+
+      # Mark that we have external filters
+      def register_external_filter
+        @has_external_filters = true
+      end
+
+      # Check if external filters are used
+      def has_external_filters?
+        @has_external_filters
+      end
+
+      # Register an external tag that will be called at runtime
+      # @param tag [Liquid::Tag] The tag to register
+      # @return [String] The variable name for this tag
+      def register_external_tag(tag)
+        @external_tag_counter += 1
+        var_name = "__ext_tag_#{@external_tag_counter}__"
+        @external_tags[var_name] = tag
+        var_name
+      end
+
+      # Get all registered external tags
+      # @return [Hash] Map of variable names to tag objects
+      def external_tags
+        @external_tags
+      end
+
+      # Get the file system for loading partials
+      def file_system
+        @options[:file_system] || @template.instance_variable_get(:@environment)&.file_system
+      end
+
+      # Load a partial source from the file system
+      # @param name [String] The partial name
+      # @return [String, nil] The partial source or nil if not found
+      def load_partial(name)
+        return @partial_sources[name] if @partial_sources.key?(name)
+
+        fs = file_system
+        return nil unless fs && fs.respond_to?(:read_template_file)
+
+        begin
+          source = fs.read_template_file(name)
+          @partial_sources[name] = source
+          source
+        rescue Liquid::FileSystemError
+          nil
+        end
+      end
+
+      # Register a partial and return its method name
+      # @param name [String] The partial name
+      # @param source [String] The partial source
+      # @return [String] The method name for this partial
+      def register_partial(name, source)
+        return @partials[name] if @partials.key?(name)
+
+        @partial_counter += 1
+        method_name = "__partial_#{@partial_counter}__"
+        @partials[name] = method_name
+        method_name
+      end
+
+      # Get all registered partials
+      def registered_partials
+        @partials
+      end
+
+      # Check if debug mode is enabled
+      def debug?
+        @options[:debug]
+      end
+
+      # Emit a debug comment with source location info
+      # This creates a lightweight source map that allows tracing errors
+      # back to the original Liquid source
+      def emit_debug_comment(code, node, description = nil)
+        return unless debug?
+
+        line_number = node.respond_to?(:line_number) ? node.line_number : nil
+        raw_markup = extract_raw_markup(node)
+
+        comment_parts = []
+        comment_parts << "LIQUID"
+        comment_parts << "L#{line_number}" if line_number
+        comment_parts << description if description
+        comment_parts << raw_markup.inspect if raw_markup && raw_markup.length < 80
+
+        code.line "# #{comment_parts.join(' | ')}"
+      end
+
+      # Extract the raw markup from a node for debug output
+      def extract_raw_markup(node)
+        case node
+        when Variable
+          "{{ #{node.raw} }}"
+        when Tag
+          if node.respond_to?(:raw)
+            "{% #{node.tag_name} #{node.raw} %}"
+          elsif node.respond_to?(:markup)
+            "{% #{node.tag_name} #{node.markup} %}"
+          else
+            "{% #{node.class.name.split('::').last.downcase} %}"
+          end
+        else
+          nil
+        end
+      end
+
+      # Compile the template to a Ruby code string
+      # @return [String] Ruby code that can be eval'd to create a render proc
+      # @return [Hash] If external tags are used, returns { code: String, external_tags: Hash }
+      def compile
+        code = CodeGenerator.new
+
+        # Add debug header if enabled
+        if debug?
+          code.line "# Compiled from Liquid template: #{@template.name || '(unnamed)'}"
+          code.line "# Debug mode enabled - comments contain source locations"
+          code.line "# Format: # LIQUID | L<line> | <description> | <source>"
+          code.blank_line
+        end
+
+        # First pass: compile the document body to discover partials and external tags
+        main_code = CodeGenerator.new
+        compile_node(@template.root, main_code)
+
+        # Determine lambda parameters based on external dependencies
+        params = ["assigns = {}"]
+        params << "__external_tags__ = {}" unless @external_tags.empty?
+        params << "__filter_handler__ = nil" if @has_external_filters
+        params << "__context__ = nil"
+
+        code.line "->(#{params.join(', ')}) do"
+
+        code.indent do
+          # Initialize the output buffer
+          code.line '__output__ = +""'
+          code.blank_line
+
+          # Create a compiled context if not provided (for Drop support)
+          code.line "# Create context for Drop support"
+          code.line "__context__ ||= Liquid::Compile::CompiledContext.new(assigns)"
+          code.blank_line
+
+          # Compile helper methods if needed
+          if @options[:include_filters]
+            compile_helper_methods(code)
+            code.blank_line
+          end
+
+          # Add external tag runtime helper if needed
+          unless @external_tags.empty?
+            compile_external_tag_helper(code)
+            code.blank_line
+          end
+
+          # Add external filter helper if needed
+          if @has_external_filters
+            compile_filter_helper(code)
+            code.blank_line
+          end
+
+          # Compile partial methods (before main body so they're available)
+          compile_partials(code)
+
+          # Add the main body code
+          code.raw(main_code.to_s)
+
+          code.blank_line
+          code.line "__output__"
+        end
+        code.line "end"
+
+        code.to_s
+      end
+
+      # Compile helper for calling external tags at runtime
+      def compile_external_tag_helper(code)
+        code.line "# Helper for calling external (unknown) tags at runtime"
+        code.line "__call_external_tag__ = ->(tag_var, tag_assigns) {"
+        code.indent do
+          code.line "tag = __external_tags__[tag_var]"
+          code.line "next '' unless tag"
+          code.line "# Create a context using the default environment (which has filters registered)"
+          code.line "ctx = Liquid::Context.new([tag_assigns], {}, {}, false, nil, {}, Liquid::Environment.default)"
+          code.line "output = +''"
+          code.line "# Use render_to_output_buffer to ensure block tags work correctly"
+          code.line "tag.render_to_output_buffer(ctx, output)"
+          code.line "output"
+        end
+        code.line "}"
+      end
+
+      # Compile helper for calling external filters at runtime
+      def compile_filter_helper(code)
+        code.line "# Helper for calling external (unknown) filters at runtime"
+        code.line "__call_filter__ = ->(name, input, args) {"
+        code.indent do
+          code.line "if __filter_handler__&.respond_to?(name)"
+          code.indent do
+            code.line "__filter_handler__.send(name, input, *args)"
+          end
+          code.line "else"
+          code.indent do
+            code.line "input # Return input unchanged if filter not found"
+          end
+          code.line "end"
+        end
+        code.line "}"
+      end
+
+      # Compile all registered partials as inner methods
+      def compile_partials(code)
+        @partials.each do |name, method_name|
+          source = @partial_sources[name]
+          next unless source
+
+          code.line "# Partial: #{name}"
+          code.line "#{method_name} = ->(partial_assigns) do"
+          code.indent do
+            code.line "__partial_output__ = +''"
+            code.line "# Merge partial assigns with parent assigns"
+            code.line "__assigns_backup__ = assigns.dup"
+            code.line "assigns.merge!(partial_assigns)"
+            code.blank_line
+
+            # Parse and compile the partial
+            # Note: We need to handle this carefully to avoid circular references
+            begin
+              compile_partial_source(source, code)
+            rescue => e
+              code.line "# Error compiling partial: #{e.message.inspect}"
+              code.line "__partial_output__ << '[PARTIAL ERROR: ' + #{name.inspect} + ']'"
+            end
+
+            code.blank_line
+            code.line "# Restore assigns"
+            code.line "assigns.replace(__assigns_backup__)"
+            code.line "__partial_output__"
+          end
+          code.line "end"
+          code.blank_line
+        end
+      end
+
+      # Compile a partial source string
+      def compile_partial_source(source, code)
+        # Parse the partial source using the same environment
+        environment = @template.instance_variable_get(:@environment) || Liquid::Environment.default
+        parse_context = Liquid::ParseContext.new(environment: environment)
+        tokenizer = parse_context.new_tokenizer(source)
+        document = Liquid::Document.parse(tokenizer, parse_context)
+
+        # Compile the partial's body, but swap output variable
+        code.line "__saved_output__ = __output__"
+        code.line "__output__ = __partial_output__"
+
+        # Compile the document
+        BlockBodyCompiler.compile(document.body, self, code)
+
+        code.line "__output__ = __saved_output__"
+      end
+
+      # Generate a unique variable name for internal use
+      def generate_var_name(prefix = "v")
+        @var_counter += 1
+        "__#{prefix}#{@var_counter}__"
+      end
+
+      # Compile a single node
+      def compile_node(node, code)
+        case node
+        when Document
+          BlockBodyCompiler.compile(node.body, self, code)
+        when BlockBody
+          BlockBodyCompiler.compile(node, self, code)
+        when String
+          compile_string(node, code)
+        when Variable
+          emit_debug_comment(code, node, "variable")
+          VariableCompiler.compile(node, self, code)
+        when Tag
+          emit_debug_comment(code, node, node.class.name.split('::').last.downcase)
+          compile_tag(node, code)
+        else
+          raise CompileError, "Unknown node type: #{node.class}"
+        end
+      end
+
+      private
+
+      def compile_string(str, code)
+        return if str.empty?
+        if debug? && str.length < 40
+          code.line "# LIQUID | text | #{str.inspect}"
+        end
+        code.line "__output__ << #{str.inspect}"
+      end
+
+      def compile_tag(tag, code)
+        compiler_class = find_tag_compiler(tag)
+        if compiler_class
+          compiler_class.compile(tag, self, code)
+        else
+          # Unknown tag - delegate to the original tag's render method at runtime
+          compile_external_tag(tag, code)
+        end
+      end
+
+      def compile_external_tag(tag, code)
+        tag_var = register_external_tag(tag)
+        tag_name = tag.class.name.split('::').last
+        if debug?
+          code.line "# External tag: #{tag_name} (delegated to runtime)"
+          code.line "$stderr.puts '* WARN: Liquid external tag call - #{tag_name} (not compiled, delegated to runtime)' if $VERBOSE"
+        end
+        code.line "__output__ << __call_external_tag__.call(#{tag_var.inspect}, assigns)"
+      end
+
+      def find_tag_compiler(tag)
+        case tag
+        when Liquid::Unless  # Check Unless before If since Unless < If
+          Tags::UnlessCompiler
+        when Liquid::If
+          Tags::IfCompiler
+        when Liquid::Case
+          Tags::CaseCompiler
+        when Liquid::For
+          Tags::ForCompiler
+        when Liquid::Assign
+          Tags::AssignCompiler
+        when Liquid::Capture
+          Tags::CaptureCompiler
+        when Liquid::Cycle
+          Tags::CycleCompiler
+        when Liquid::Increment
+          Tags::IncrementCompiler
+        when Liquid::Decrement
+          Tags::DecrementCompiler
+        when Liquid::Raw
+          Tags::RawCompiler
+        when Liquid::Echo
+          Tags::EchoCompiler
+        when Liquid::Break
+          Tags::BreakCompiler
+        when Liquid::Continue
+          Tags::ContinueCompiler
+        when Liquid::Comment, Liquid::InlineComment, Liquid::Doc
+          Tags::CommentCompiler
+        when Liquid::TableRow
+          Tags::TableRowCompiler
+        when Liquid::Render
+          Tags::RenderCompiler
+        when Liquid::Include
+          Tags::IncludeCompiler
+        when Liquid::Ifchanged
+          Tags::IfchangedCompiler
+        else
+          nil
+        end
+      end
+
+      def compile_helper_methods(code)
+        code.line "# Helper methods for filters and utilities"
+
+        # to_s helper that handles arrays and hashes like Liquid does
+        code.line "def __to_s__(obj)"
+        code.indent do
+          code.line "case obj"
+          code.line "when NilClass then ''"
+          code.line "when Array then obj.join"
+          code.line "else obj.to_s"
+          code.line "end"
+        end
+        code.line "end"
+        code.blank_line
+
+        # to_number helper
+        code.line "def __to_number__(obj)"
+        code.indent do
+          code.line "case obj"
+          code.line "when Numeric then obj"
+          code.line "when String"
+          code.indent do
+            code.line "obj.strip =~ /\\A-?\\d+\\.\\d+\\z/ ? BigDecimal(obj) : obj.to_i"
+          end
+          code.line "else 0"
+          code.line "end"
+        end
+        code.line "end"
+        code.blank_line
+
+        # to_integer helper
+        code.line "def __to_integer__(obj)"
+        code.indent do
+          code.line "return obj if obj.is_a?(Integer)"
+          code.line "Integer(obj.to_s)"
+        end
+        code.line "end"
+        code.blank_line
+
+        # Liquid truthiness helper
+        code.line "def __truthy__(obj)"
+        code.indent do
+          code.line "obj != nil && obj != false"
+        end
+        code.line "end"
+        code.blank_line
+
+        # Variable lookup helper - handles hash/array access, method calls, to_liquid, and drop context
+        code.line "__lookup__ = ->(obj, key) {"
+        code.indent do
+          code.line "return nil if obj.nil?"
+          code.line "# Set context on Drops BEFORE accessing their methods"
+          code.line "obj = obj.to_liquid if obj.respond_to?(:to_liquid)"
+          code.line "obj.context = __context__ if obj.respond_to?(:context=)"
+          code.line "# Now perform the lookup"
+          code.line "result = if obj.respond_to?(:[]) && (obj.respond_to?(:key?) && obj.key?(key) || obj.respond_to?(:fetch) && key.is_a?(Integer))"
+          code.indent do
+            code.line "obj[key]"
+          end
+          code.line "elsif obj.respond_to?(key)"
+          code.indent do
+            code.line "obj.send(key)"
+          end
+          code.line "else"
+          code.indent do
+            code.line "nil"
+          end
+          code.line "end"
+          code.line "# Convert result to liquid and set context for nested Drops"
+          code.line "result = result.to_liquid if result.respond_to?(:to_liquid)"
+          code.line "result.context = __context__ if result.respond_to?(:context=)"
+          code.line "result"
+        end
+        code.line "}"
+        code.blank_line
+
+        # Output helper that handles nil and arrays
+        code.line "def __output_value__(obj)"
+        code.indent do
+          code.line "case obj"
+          code.line "when NilClass then ''"
+          code.line "when Array then obj.map { |o| __output_value__(o) }.join"
+          code.line "else obj.to_s"
+          code.line "end"
+        end
+        code.line "end"
+      end
+    end
+
+    # Custom error for compilation issues
+    class CompileError < StandardError; end
+  end
+end

lib/liquid/compile/source_mapper.rb

@@ -0,0 +1,130 @@
+# frozen_string_literal: true
+
+module Liquid
+  module Compile
+    # SourceMapper provides utilities for mapping errors in compiled Ruby code
+    # back to the original Liquid source.
+    #
+    # When code is compiled with debug: true, comments are embedded that contain
+    # source location information. This class can parse those comments and
+    # help trace errors back to the original Liquid template.
+    #
+    # ## Usage
+    #
+    #   template = Liquid::Template.parse(source, line_numbers: true)
+    #   ruby_code = template.compile_to_ruby(debug: true)
+    #   render_proc = eval(ruby_code)
+    #
+    #   begin
+    #     result = render_proc.call(assigns)
+    #   rescue => e
+    #     location = SourceMapper.find_source_location(ruby_code, e)
+    #     puts "Error at Liquid line #{location[:liquid_line]}: #{location[:source]}"
+    #   end
+    #
+    class SourceMapper
+      # Pattern to match LIQUID debug comments
+      LIQUID_COMMENT_PATTERN = /^(\s*)# LIQUID(?: \| L(\d+))?(?: \| ([^|]+))?(?: \| (.+))?$/
+
+      # Parse compiled Ruby code and extract source mapping entries
+      # @param ruby_code [String] The compiled Ruby code with debug comments
+      # @return [Array<Hash>] Array of source mapping entries
+      def self.parse(ruby_code)
+        entries = []
+        ruby_line = 0
+
+        ruby_code.each_line do |line|
+          ruby_line += 1
+
+          if line =~ LIQUID_COMMENT_PATTERN
+            entries << {
+              ruby_line: ruby_line,
+              liquid_line: $2&.to_i,
+              type: $3&.strip,
+              source: parse_source_string($4),
+            }
+          end
+        end
+
+        entries
+      end
+
+      # Find the source location for an error based on Ruby line number
+      # @param ruby_code [String] The compiled Ruby code
+      # @param error [Exception] The exception that was raised
+      # @return [Hash, nil] Source location info or nil if not found
+      def self.find_source_location(ruby_code, error)
+        # Extract the line number from the error
+        ruby_line = extract_error_line(error)
+        return nil unless ruby_line
+
+        find_source_for_ruby_line(ruby_code, ruby_line)
+      end
+
+      # Find the source location for a specific Ruby line number
+      # @param ruby_code [String] The compiled Ruby code
+      # @param target_line [Integer] The Ruby line number
+      # @return [Hash, nil] Source location info or nil if not found
+      def self.find_source_for_ruby_line(ruby_code, target_line)
+        entries = parse(ruby_code)
+
+        # Find the closest LIQUID comment at or before the target line
+        closest = nil
+        entries.each do |entry|
+          break if entry[:ruby_line] > target_line
+          closest = entry
+        end
+
+        closest
+      end
+
+      # Format an error message with source location info
+      # @param ruby_code [String] The compiled Ruby code
+      # @param error [Exception] The exception
+      # @return [String] Formatted error message
+      def self.format_error(ruby_code, error)
+        location = find_source_location(ruby_code, error)
+
+        message = "#{error.class}: #{error.message}"
+
+        if location
+          liquid_line = location[:liquid_line] ? "line #{location[:liquid_line]}" : "unknown line"
+          source = location[:source] || location[:type] || "unknown"
+          message += "\n  in Liquid template at #{liquid_line}"
+          message += "\n  source: #{source}" if location[:source]
+        end
+
+        message
+      end
+
+      private
+
+      def self.extract_error_line(error)
+        # Look for (eval):N in backtrace
+        error.backtrace&.each do |frame|
+          if frame =~ /\(eval.*?\):(\d+)/
+            return $1.to_i
+          end
+        end
+        nil
+      end
+
+      def self.parse_source_string(str)
+        return nil unless str
+
+        # Remove surrounding quotes if present
+        str = str.strip
+        if str.start_with?('"') && str.end_with?('"')
+          # Unescape the string
+          begin
+            eval(str)
+          rescue
+            str[1..-2]
+          end
+        else
+          str
+        end
+      end
+    end
+  end
+end

lib/liquid/compile/tags/assign_compiler.rb

@@ -0,0 +1,19 @@
+# frozen_string_literal: true
+
+module Liquid
+  module Compile
+    module Tags
+      # Compiles {% assign var = expression %} tags
+      class AssignCompiler
+        def self.compile(tag, compiler, code)
+          var_name = tag.to
+          # Use VariableCompiler to get the expression with filters applied
+          value_expr = VariableCompiler.compile_to_expression(tag.from, compiler)
+
+          # Store in the assigns hash
+          code.line "assigns[#{var_name.inspect}] = #{value_expr}"
+        end
+      end
+    end
+  end
+end

lib/liquid/compile/tags/break_compiler.rb

@@ -0,0 +1,18 @@
+# frozen_string_literal: true
+
+module Liquid
+  module Compile
+    module Tags
+      # Compiles {% break %} tags
+      #
+      # Breaks out of a for loop
+      class BreakCompiler
+        def self.compile(_tag, _compiler, code)
+          # We use throw/catch in the for loop to handle break
+          # This allows break to work from nested blocks
+          code.line "throw :__loop__break__"
+        end
+      end
+    end
+  end
+end

lib/liquid/compile/tags/capture_compiler.rb

@@ -0,0 +1,31 @@
+# frozen_string_literal: true
+
+module Liquid
+  module Compile
+    module Tags
+      # Compiles {% capture var %}...{% endcapture %} tags
+      #
+      # Captures the output of the block into a variable
+      class CaptureCompiler
+        def self.compile(tag, compiler, code)
+          var_name = tag.instance_variable_get(:@to)
+          capture_var = compiler.generate_var_name("capture")
+
+          # Save current output, create new buffer for capture
+          code.line "#{capture_var} = __output__"
+          code.line "__output__ = +''"
+
+          # Compile the body - access the @body BlockBody directly
+          body = tag.instance_variable_get(:@body)
+          if body
+            BlockBodyCompiler.compile(body, compiler, code)
+          end
+
+          # Save captured content and restore output buffer
+          code.line "assigns[#{var_name.inspect}] = __output__"
+          code.line "__output__ = #{capture_var}"
+        end
+      end
+    end
+  end
+end

lib/liquid/compile/tags/case_compiler.rb

@@ -0,0 +1,47 @@
+# frozen_string_literal: true
+
+module Liquid
+  module Compile
+    module Tags
+      # Compiles {% case %} / {% when %} / {% else %} / {% endcase %} tags
+      class CaseCompiler
+        def self.compile(tag, compiler, code)
+          # Compile the case expression and store it in a variable
+          # to avoid evaluating it multiple times
+          case_var = compiler.generate_var_name("case")
+          case_expr = ExpressionCompiler.compile(tag.left, compiler)
+          code.line "#{case_var} = #{case_expr}"
+
+          blocks = tag.blocks
+          is_first = true
+          has_else = false
+
+          blocks.each do |block|
+            if block.else?
+              has_else = true
+              code.line "else"
+            else
+              # 'when' condition - compare case expression with the when value
+              when_expr = ExpressionCompiler.compile(block.right, compiler)
+
+              if is_first
+                code.line "if #{case_var} == #{when_expr}"
+                is_first = false
+              else
+                code.line "elsif #{case_var} == #{when_expr}"
+              end
+            end
+
+            code.indent do
+              if block.attachment
+                BlockBodyCompiler.compile(block.attachment, compiler, code)
+              end
+            end
+          end
+
+          code.line "end" unless blocks.empty?
+        end
+      end
+    end
+  end
+end

lib/liquid/compile/tags/comment_compiler.rb

@@ -0,0 +1,18 @@
+# frozen_string_literal: true
+
+module Liquid
+  module Compile
+    module Tags
+      # Compiles {% comment %}...{% endcomment %} tags
+      # Also handles inline_comment (#) and doc tags
+      #
+      # Comments produce no output
+      class CommentCompiler
+        def self.compile(_tag, _compiler, code)
+          # Comments produce no output
+          code.line "# (liquid comment)"
+        end
+      end
+    end
+  end
+end

lib/liquid/compile/tags/continue_compiler.rb

@@ -0,0 +1,17 @@
+# frozen_string_literal: true
+
+module Liquid
+  module Compile
+    module Tags
+      # Compiles {% continue %} tags
+      #
+      # Skips to the next iteration of a for loop
+      class ContinueCompiler
+        def self.compile(_tag, _compiler, code)
+          # We use throw/catch in the for loop to handle continue
+          code.line "throw :__loop__continue__"
+        end
+      end
+    end
+  end
+end

lib/liquid/compile/tags/cycle_compiler.rb

@@ -0,0 +1,45 @@
+# frozen_string_literal: true
+
+module Liquid
+  module Compile
+    module Tags
+      # Compiles {% cycle 'a', 'b', 'c' %} tags
+      #
+      # Cycles through a list of values, outputting the next one each iteration
+      class CycleCompiler
+        def self.compile(tag, compiler, code)
+          variables = tag.variables
+          name_expr = ExpressionCompiler.compile(tag.instance_variable_get(:@name), compiler)
+          is_named = tag.named?
+
+          cycle_var = compiler.generate_var_name("cycle")
+          key_var = compiler.generate_var_name("cycle_key")
+
+          # Initialize cycle storage if needed
+          code.line "assigns[:__cycle__] ||= {}"
+
+          # Get the cycle key
+          if is_named
+            code.line "#{key_var} = #{name_expr}"
+          else
+            code.line "#{key_var} = #{variables.object_id}"
+          end
+
+          # Get current index
+          code.line "#{cycle_var} = assigns[:__cycle__][#{key_var}].to_i"
+
+          # Get the value at current index
+          code.line "case #{cycle_var} % #{variables.size}"
+          variables.each_with_index do |var, idx|
+            var_expr = ExpressionCompiler.compile(var, compiler)
+            code.line "when #{idx} then __output__ << __to_s__(#{var_expr})"
+          end
+          code.line "end"
+
+          # Increment counter
+          code.line "assigns[:__cycle__][#{key_var}] = #{cycle_var} + 1"
+        end
+      end
+    end
+  end
+end

lib/liquid/compile/tags/decrement_compiler.rb

@@ -0,0 +1,26 @@
+# frozen_string_literal: true
+
+module Liquid
+  module Compile
+    module Tags
+      # Compiles {% decrement var %} tags
+      #
+      # Decrements a counter and outputs its value.
+      # Uses a separate namespace from regular assigns (shares with increment).
+      class DecrementCompiler
+        def self.compile(tag, compiler, code)
+          var_name = tag.variable_name
+
+          # Initialize counter storage if needed
+          code.line "assigns[:__counters__] ||= {}"
+
+          # Get current value (default 0), decrement it, output, then store
+          dec_var = compiler.generate_var_name("dec")
+          code.line "#{dec_var} = (assigns[:__counters__][#{var_name.inspect}] || 0) - 1"
+          code.line "assigns[:__counters__][#{var_name.inspect}] = #{dec_var}"
+          code.line "__output__ << #{dec_var}.to_s"
+        end
+      end
+    end
+  end
+end

lib/liquid/compile/tags/echo_compiler.rb

@@ -0,0 +1,17 @@
+# frozen_string_literal: true
+
+module Liquid
+  module Compile
+    module Tags
+      # Compiles {% echo expression %} tags
+      #
+      # Same as {{ expression }} but usable in {% liquid %} blocks
+      class EchoCompiler
+        def self.compile(tag, compiler, code)
+          variable = tag.variable
+          VariableCompiler.compile(variable, compiler, code)
+        end
+      end
+    end
+  end
+end

lib/liquid/compile/tags/for_compiler.rb

@@ -0,0 +1,127 @@
+# frozen_string_literal: true
+
+module Liquid
+  module Compile
+    module Tags
+      # Compiles {% for %} / {% else %} / {% endfor %} tags
+      #
+      # Supports:
+      # - Iteration: {% for item in collection %}
+      # - Limit/Offset: {% for item in collection limit:3 offset:2 %}
+      # - Reversed: {% for item in collection reversed %}
+      # - Forloop object: forloop.index, forloop.first, forloop.last, etc.
+      # - Else block: {% for item in collection %}...{% else %}empty{% endfor %}
+      class ForCompiler
+        def self.compile(tag, compiler, code)
+          var_name = tag.variable_name
+          collection_expr = ExpressionCompiler.compile(tag.collection_name, compiler)
+
+          # Generate unique variable names for this loop
+          coll_var = compiler.generate_var_name("coll")
+          idx_var = compiler.generate_var_name("idx")
+          len_var = compiler.generate_var_name("len")
+
+          # Evaluate the collection
+          code.line "#{coll_var} = #{collection_expr}"
+          code.line "#{coll_var} = #{coll_var}.to_a if #{coll_var}.is_a?(Range)"
+
+          # Handle limit and offset
+          if tag.from || tag.limit
+            compile_slice(tag, coll_var, compiler, code)
+          end
+
+          # Handle reversed
+          if tag.instance_variable_get(:@reversed)
+            code.line "#{coll_var} = #{coll_var}.reverse"
+          end
+
+          # Check if collection is empty for else block
+          for_block = tag.instance_variable_get(:@for_block)
+          else_block = tag.instance_variable_get(:@else_block)
+
+          if else_block
+            code.line "if #{coll_var}.nil? || (#{coll_var}.respond_to?(:empty?) && #{coll_var}.empty?)"
+            code.indent do
+              BlockBodyCompiler.compile(else_block, compiler, code)
+            end
+            code.line "else"
+            code.indent do
+              compile_loop(tag, var_name, coll_var, idx_var, len_var, for_block, compiler, code)
+            end
+            code.line "end"
+          else
+            compile_loop(tag, var_name, coll_var, idx_var, len_var, for_block, compiler, code)
+          end
+        end
+
+        private
+
+        def self.compile_slice(tag, coll_var, compiler, code)
+          from_expr = if tag.from == :continue
+            # Continue from previous offset - we'd need register tracking for this
+            # For now, default to 0
+            "0"
+          elsif tag.from
+            ExpressionCompiler.compile(tag.from, compiler)
+          else
+            "0"
+          end
+
+          if tag.limit
+            limit_expr = ExpressionCompiler.compile(tag.limit, compiler)
+            code.line "#{coll_var} = (#{coll_var}.respond_to?(:slice) ? #{coll_var}.slice(__to_integer__(#{from_expr}), __to_integer__(#{limit_expr})) : #{coll_var}) || []"
+          else
+            code.line "#{coll_var} = (#{coll_var}.respond_to?(:drop) ? #{coll_var}.drop(__to_integer__(#{from_expr})) : #{coll_var}) || []"
+          end
+        end
+
+        def self.compile_loop(tag, var_name, coll_var, idx_var, len_var, for_block, compiler, code)
+          # Calculate length for forloop
+          code.line "#{len_var} = #{coll_var}.respond_to?(:length) ? #{coll_var}.length : 0"
+          code.line "#{idx_var} = 0"
+
+          # The loop itself - use catch/throw for break support across nested blocks
+          code.line "catch(:__loop__break__) do"
+          code.indent do
+            code.line "(#{coll_var}.respond_to?(:each) ? #{coll_var} : []).each do |__item__|"
+            code.indent do
+              # Wrap each iteration in a catch for continue support
+              code.line "catch(:__loop__continue__) do"
+              code.indent do
+                # Set the loop variable
+                code.line "assigns[#{var_name.inspect}] = __item__"
+
+                # Build the forloop object as a hash
+                code.line "assigns['forloop'] = {"
+                code.indent do
+                  code.line "'name' => #{tag.instance_variable_get(:@name).inspect},"
+                  code.line "'length' => #{len_var},"
+                  code.line "'index' => #{idx_var} + 1,"
+                  code.line "'index0' => #{idx_var},"
+                  code.line "'rindex' => #{len_var} - #{idx_var},"
+                  code.line "'rindex0' => #{len_var} - #{idx_var} - 1,"
+                  code.line "'first' => #{idx_var} == 0,"
+                  code.line "'last' => #{idx_var} == #{len_var} - 1,"
+                end
+                code.line "}"
+
+                # Compile the loop body
+                BlockBodyCompiler.compile(for_block, compiler, code)
+              end
+              code.line "end"
+
+              # Increment index (runs even after continue)
+              code.line "#{idx_var} += 1"
+            end
+            code.line "end"
+          end
+          code.line "end"
+
+          # Clean up
+          code.line "assigns.delete(#{var_name.inspect})"
+          code.line "assigns.delete('forloop')"
+        end
+      end
+    end
+  end
+end

lib/liquid/compile/tags/if_compiler.rb

@@ -0,0 +1,34 @@
+# frozen_string_literal: true
+
+module Liquid
+  module Compile
+    module Tags
+      # Compiles {% if %} / {% elsif %} / {% else %} / {% endif %} tags
+      class IfCompiler
+        def self.compile(tag, compiler, code)
+          blocks = tag.blocks
+
+          blocks.each_with_index do |block, index|
+            condition_expr = ConditionCompiler.compile(block, compiler)
+
+            if index == 0
+              code.line "if #{condition_expr}"
+            elsif block.else?
+              code.line "else"
+            else
+              code.line "elsif #{condition_expr}"
+            end
+
+            code.indent do
+              if block.attachment
+                BlockBodyCompiler.compile(block.attachment, compiler, code)
+              end
+            end
+          end
+
+          code.line "end"
+        end
+      end
+    end
+  end
+end

lib/liquid/compile/tags/ifchanged_compiler.rb

@@ -0,0 +1,40 @@
+# frozen_string_literal: true
+
+module Liquid
+  module Compile
+    module Tags
+      # Compiles {% ifchanged %}...{% endifchanged %} tags
+      #
+      # Only outputs if the content has changed since last render
+      class IfchangedCompiler
+        def self.compile(tag, compiler, code)
+          capture_var = compiler.generate_var_name("ifchanged")
+
+          # Capture the block output
+          code.line "#{capture_var} = +''"
+          code.line "begin"
+          code.indent do
+            code.line "__saved_output__ = __output__"
+            code.line "__output__ = #{capture_var}"
+
+            # Compile the body
+            tag.nodelist.each do |body|
+              BlockBodyCompiler.compile(body, compiler, code)
+            end
+
+            code.line "__output__ = __saved_output__"
+          end
+          code.line "end"
+
+          # Only output if changed
+          code.line "if #{capture_var} != assigns[:__ifchanged__]"
+          code.indent do
+            code.line "assigns[:__ifchanged__] = #{capture_var}"
+            code.line "__output__ << #{capture_var}"
+          end
+          code.line "end"
+        end
+      end
+    end
+  end
+end

lib/liquid/compile/tags/include_compiler.rb

@@ -0,0 +1,128 @@
+# frozen_string_literal: true
+
+module Liquid
+  module Compile
+    module Tags
+      # Compiles {% include 'partial' %} tags
+      #
+      # Include is deprecated in favor of render, but we support it for compatibility.
+      # Unlike render, include shares the outer scope with the partial.
+      #
+      # For static template names, the partial is loaded and inlined at compile time.
+      # For dynamic template names, a runtime fallback is generated.
+      class IncludeCompiler
+        def self.compile(tag, compiler, code)
+          template_name_expr = tag.template_name_expr
+          variable_name_expr = tag.variable_name_expr
+          attributes = tag.attributes
+          alias_name = tag.instance_variable_get(:@alias_name)
+
+          # Check if the template name is a static string
+          if template_name_expr.is_a?(String)
+            compile_static_include(tag, template_name_expr, compiler, code)
+          else
+            compile_dynamic_include(tag, compiler, code)
+          end
+        end
+
+        private
+
+        def self.compile_static_include(tag, template_name, compiler, code)
+          variable_name_expr = tag.variable_name_expr
+          attributes = tag.attributes
+          alias_name = tag.instance_variable_get(:@alias_name)
+
+          # Try to load the partial at compile time
+          partial_source = compiler.load_partial(template_name)
+
+          if partial_source
+            if compiler.debug?
+              code.line "# Inlined partial #{template_name.inspect} at compile time"
+              code.line "$stderr.puts '* WARN: Liquid file system access - inlined partial ' + #{template_name.inspect} + ' at compile time' if $VERBOSE"
+            end
+            # Generate a unique method name for this partial
+            method_name = compiler.register_partial(template_name, partial_source)
+            context_var_name = alias_name || template_name.split('/').last
+
+            # Include shares scope, so we just set variables directly
+            code.line "# Include: #{template_name}"
+
+            # Set attributes
+            attributes.each do |key, value|
+              value_expr = ExpressionCompiler.compile(value, compiler)
+              code.line "assigns[#{key.inspect}] = #{value_expr}"
+            end
+
+            # Set the context variable
+            if variable_name_expr
+              var_expr = ExpressionCompiler.compile(variable_name_expr, compiler)
+              var_var = compiler.generate_var_name("incvar")
+              code.line "#{var_var} = #{var_expr}"
+
+              # If it's an array, loop through it
+              code.line "if #{var_var}.is_a?(Array)"
+              code.indent do
+                code.line "#{var_var}.each do |__include_item__|"
+                code.indent do
+                  code.line "assigns[#{context_var_name.inspect}] = __include_item__"
+                  code.line "__output__ << #{method_name}({})"
+                end
+                code.line "end"
+              end
+              code.line "else"
+              code.indent do
+                code.line "assigns[#{context_var_name.inspect}] = #{var_var}"
+                code.line "__output__ << #{method_name}({})"
+              end
+              code.line "end"
+            else
+              # Try to find a variable with the same name as the template
+              code.line "assigns[#{context_var_name.inspect}] = assigns[#{template_name.inspect}] if assigns.key?(#{template_name.inspect})"
+              code.line "__output__ << #{method_name}({})"
+            end
+          else
+            # Partial not found at compile time
+            code.line "# Partial '#{template_name}' not found at compile time"
+            compile_dynamic_include(tag, compiler, code)
+          end
+        end
+
+        def self.compile_dynamic_include(tag, compiler, code)
+          template_name_expr = tag.template_name_expr
+          variable_name_expr = tag.variable_name_expr
+          attributes = tag.attributes
+          alias_name = tag.instance_variable_get(:@alias_name)
+
+          if compiler.debug?
+            code.line "# Dynamic include (template name from variable)"
+            code.line "$stderr.puts '* WARN: Liquid runtime file system access - dynamic include (template name from variable)' if $VERBOSE"
+          end
+
+          name_expr = ExpressionCompiler.compile(template_name_expr, compiler)
+
+          # Build attributes hash
+          attrs_var = compiler.generate_var_name("attrs")
+          code.line "#{attrs_var} = {}"
+          attributes.each do |key, value|
+            value_expr = ExpressionCompiler.compile(value, compiler)
+            code.line "#{attrs_var}[#{key.inspect}] = #{value_expr}"
+          end
+
+          var_expr = variable_name_expr ? ExpressionCompiler.compile(variable_name_expr, compiler) : "nil"
+          alias_expr = alias_name ? alias_name.inspect : "nil"
+
+          # Call the runtime dynamic include method
+          code.line "if defined?(__include_dynamic__)"
+          code.indent do
+            code.line "__output__ << __include_dynamic__(#{name_expr}, #{var_expr}, #{attrs_var}, #{alias_expr}, assigns)"
+          end
+          code.line "else"
+          code.indent do
+            code.line "raise RuntimeError, 'Dynamic include requires __include_dynamic__ method: ' + #{name_expr}.inspect"
+          end
+          code.line "end"
+        end
+      end
+    end
+  end
+end

lib/liquid/compile/tags/increment_compiler.rb

@@ -0,0 +1,26 @@
+# frozen_string_literal: true
+
+module Liquid
+  module Compile
+    module Tags
+      # Compiles {% increment var %} tags
+      #
+      # Outputs the current counter value, then increments it.
+      # Uses a separate namespace from regular assigns (shares with decrement).
+      class IncrementCompiler
+        def self.compile(tag, compiler, code)
+          var_name = tag.variable_name
+
+          # Initialize counter storage if needed
+          code.line "assigns[:__counters__] ||= {}"
+
+          # Get current value (default 0), output it, then increment
+          inc_var = compiler.generate_var_name("inc")
+          code.line "#{inc_var} = assigns[:__counters__][#{var_name.inspect}] || 0"
+          code.line "__output__ << #{inc_var}.to_s"
+          code.line "assigns[:__counters__][#{var_name.inspect}] = #{inc_var} + 1"
+        end
+      end
+    end
+  end
+end

lib/liquid/compile/tags/raw_compiler.rb

@@ -0,0 +1,19 @@
+# frozen_string_literal: true
+
+module Liquid
+  module Compile
+    module Tags
+      # Compiles {% raw %}...{% endraw %} tags
+      #
+      # Outputs the content as-is without parsing Liquid syntax
+      class RawCompiler
+        def self.compile(tag, compiler, code)
+          body = tag.instance_variable_get(:@body)
+          return if body.nil? || body.empty?
+
+          code.line "__output__ << #{body.inspect}"
+        end
+      end
+    end
+  end
+end

lib/liquid/compile/tags/render_compiler.rb

@@ -0,0 +1,185 @@
+# frozen_string_literal: true
+
+module Liquid
+  module Compile
+    module Tags
+      # Compiles {% render 'partial' %} tags
+      #
+      # For static template names (string literals), the partial is loaded at
+      # compile time and inlined as a method.
+      #
+      # For dynamic template names (variables), a runtime fallback is generated
+      # that calls __render_dynamic__ which must be provided by the runtime.
+      class RenderCompiler
+        def self.compile(tag, compiler, code)
+          template_name_expr = tag.template_name_expr
+          variable_name_expr = tag.variable_name_expr
+          attributes = tag.attributes
+          alias_name = tag.alias_name
+          is_for_loop = tag.for_loop?
+
+          # Check if the template name is a static string
+          if template_name_expr.is_a?(String)
+            compile_static_render(tag, template_name_expr, compiler, code)
+          else
+            compile_dynamic_render(tag, compiler, code)
+          end
+        end
+
+        private
+
+        def self.compile_static_render(tag, template_name, compiler, code)
+          variable_name_expr = tag.variable_name_expr
+          attributes = tag.attributes
+          alias_name = tag.alias_name
+          is_for_loop = tag.for_loop?
+
+          # Try to load the partial at compile time
+          partial_source = compiler.load_partial(template_name)
+
+          if partial_source
+            if compiler.debug?
+              code.line "# Inlined partial #{template_name.inspect} at compile time"
+              code.line "$stderr.puts '* WARN: Liquid file system access - inlined partial ' + #{template_name.inspect} + ' at compile time' if $VERBOSE"
+            end
+            # Generate a unique method name for this partial
+            method_name = compiler.register_partial(template_name, partial_source)
+            context_var_name = alias_name || template_name.split('/').last
+
+            if is_for_loop && variable_name_expr
+              # Render for each item in collection
+              compile_for_loop_render(tag, method_name, context_var_name, compiler, code)
+            else
+              # Single render
+              compile_single_render(tag, method_name, context_var_name, compiler, code)
+            end
+          else
+            # Partial not found at compile time - generate runtime fallback
+            code.line "# Partial '#{template_name}' not found at compile time"
+            compile_dynamic_render(tag, compiler, code)
+          end
+        end
+
+        def self.compile_single_render(tag, method_name, context_var_name, compiler, code)
+          variable_name_expr = tag.variable_name_expr
+          attributes = tag.attributes
+
+          # Build the inner assigns hash
+          inner_assigns_var = compiler.generate_var_name("inner")
+          code.line "#{inner_assigns_var} = {}"
+
+          # Copy attributes
+          attributes.each do |key, value|
+            value_expr = ExpressionCompiler.compile(value, compiler)
+            code.line "#{inner_assigns_var}[#{key.inspect}] = #{value_expr}"
+          end
+
+          # Set the context variable if provided
+          if variable_name_expr
+            var_expr = ExpressionCompiler.compile(variable_name_expr, compiler)
+            code.line "#{inner_assigns_var}[#{context_var_name.inspect}] = #{var_expr}"
+          end
+
+          # Call the partial method
+          code.line "__output__ << #{method_name}(#{inner_assigns_var})"
+        end
+
+        def self.compile_for_loop_render(tag, method_name, context_var_name, compiler, code)
+          variable_name_expr = tag.variable_name_expr
+          attributes = tag.attributes
+          template_name = tag.template_name_expr
+
+          coll_var = compiler.generate_var_name("coll")
+          coll_expr = ExpressionCompiler.compile(variable_name_expr, compiler)
+          code.line "#{coll_var} = #{coll_expr}"
+
+          code.line "if #{coll_var}.respond_to?(:each) && #{coll_var}.respond_to?(:count)"
+          code.indent do
+            len_var = compiler.generate_var_name("len")
+            idx_var = compiler.generate_var_name("idx")
+            code.line "#{len_var} = #{coll_var}.count"
+            code.line "#{idx_var} = 0"
+
+            code.line "#{coll_var}.each do |__item__|"
+            code.indent do
+              inner_assigns_var = compiler.generate_var_name("inner")
+              code.line "#{inner_assigns_var} = {}"
+
+              # Copy attributes
+              attributes.each do |key, value|
+                value_expr = ExpressionCompiler.compile(value, compiler)
+                code.line "#{inner_assigns_var}[#{key.inspect}] = #{value_expr}"
+              end
+
+              # Set the context variable
+              code.line "#{inner_assigns_var}[#{context_var_name.inspect}] = __item__"
+
+              # Set forloop
+              code.line "#{inner_assigns_var}['forloop'] = {"
+              code.indent do
+                code.line "'name' => #{template_name.inspect},"
+                code.line "'length' => #{len_var},"
+                code.line "'index' => #{idx_var} + 1,"
+                code.line "'index0' => #{idx_var},"
+                code.line "'rindex' => #{len_var} - #{idx_var},"
+                code.line "'rindex0' => #{len_var} - #{idx_var} - 1,"
+                code.line "'first' => #{idx_var} == 0,"
+                code.line "'last' => #{idx_var} == #{len_var} - 1,"
+              end
+              code.line "}"
+
+              # Call the partial method
+              code.line "__output__ << #{method_name}(#{inner_assigns_var})"
+
+              code.line "#{idx_var} += 1"
+            end
+            code.line "end"
+          end
+          code.line "else"
+          code.indent do
+            # Single render if not a collection
+            compile_single_render(tag, method_name, context_var_name, compiler, code)
+          end
+          code.line "end"
+        end
+
+        def self.compile_dynamic_render(tag, compiler, code)
+          template_name_expr = tag.template_name_expr
+          variable_name_expr = tag.variable_name_expr
+          attributes = tag.attributes
+          alias_name = tag.alias_name
+          is_for_loop = tag.for_loop?
+
+          if compiler.debug?
+            code.line "# Dynamic render (template name from variable)"
+            code.line "$stderr.puts '* WARN: Liquid runtime file system access - dynamic render (template name from variable)' if $VERBOSE"
+          end
+
+          name_expr = ExpressionCompiler.compile(template_name_expr, compiler)
+
+          # Build attributes hash
+          attrs_var = compiler.generate_var_name("attrs")
+          code.line "#{attrs_var} = {}"
+          attributes.each do |key, value|
+            value_expr = ExpressionCompiler.compile(value, compiler)
+            code.line "#{attrs_var}[#{key.inspect}] = #{value_expr}"
+          end
+
+          var_expr = variable_name_expr ? ExpressionCompiler.compile(variable_name_expr, compiler) : "nil"
+          alias_expr = alias_name ? alias_name.inspect : "nil"
+
+          # Call the runtime dynamic render method
+          code.line "if defined?(__render_dynamic__)"
+          code.indent do
+            code.line "__output__ << __render_dynamic__(#{name_expr}, #{var_expr}, #{attrs_var}, #{alias_expr}, #{is_for_loop})"
+          end
+          code.line "else"
+          code.indent do
+            code.line "raise RuntimeError, 'Dynamic render requires __render_dynamic__ method: ' + #{name_expr}.inspect"
+          end
+          code.line "end"
+        end
+      end
+    end
+  end
+end

lib/liquid/compile/tags/tablerow_compiler.rb

@@ -0,0 +1,117 @@
+# frozen_string_literal: true
+
+module Liquid
+  module Compile
+    module Tags
+      # Compiles {% tablerow %} tags
+      #
+      # Creates HTML table rows from a collection
+      class TableRowCompiler
+        def self.compile(tag, compiler, code)
+          var_name = tag.variable_name
+          collection_expr = ExpressionCompiler.compile(tag.collection_name, compiler)
+          attributes = tag.attributes
+
+          # Generate unique variable names
+          coll_var = compiler.generate_var_name("coll")
+          idx_var = compiler.generate_var_name("idx")
+          len_var = compiler.generate_var_name("len")
+          cols_var = compiler.generate_var_name("cols")
+          row_var = compiler.generate_var_name("row")
+          col_var = compiler.generate_var_name("col")
+
+          # Get parameters from attributes hash
+          cols = attributes['cols']
+          cols_expr = cols ? ExpressionCompiler.compile(cols, compiler) : "nil"
+
+          # Evaluate the collection
+          code.line "#{coll_var} = #{collection_expr}"
+          code.line "#{coll_var} = #{coll_var}.to_a if #{coll_var}.is_a?(Range)"
+
+          # Handle limit and offset from attributes
+          offset = attributes['offset']
+          limit = attributes['limit']
+          if offset || limit
+            if offset
+              offset_expr = ExpressionCompiler.compile(offset, compiler)
+              if limit
+                limit_expr = ExpressionCompiler.compile(limit, compiler)
+                code.line "#{coll_var} = #{coll_var}.slice(__to_integer__(#{offset_expr}), __to_integer__(#{limit_expr})) || []"
+              else
+                code.line "#{coll_var} = #{coll_var}.drop(__to_integer__(#{offset_expr}))"
+              end
+            elsif limit
+              limit_expr = ExpressionCompiler.compile(limit, compiler)
+              code.line "#{coll_var} = #{coll_var}.first(__to_integer__(#{limit_expr}))"
+            end
+          end
+
+          # Setup loop variables
+          code.line "#{len_var} = #{coll_var}.respond_to?(:length) ? #{coll_var}.length : 0"
+          code.line "#{cols_var} = #{cols_expr} || #{len_var}"
+          code.line "#{idx_var} = 0"
+          code.line "#{row_var} = 1"
+          code.line "#{col_var} = 0"
+
+          body = tag.instance_variable_get(:@body)
+
+          # Output initial row (matches interpreter behavior: outputs before loop)
+          code.line "__output__ << \"<tr class=\\\"row1\\\">\\n\""
+
+          # The loop
+          code.line "(#{coll_var}.respond_to?(:each) ? #{coll_var} : []).each do |__item__|"
+          code.indent do
+            code.line "#{col_var} += 1"
+
+            # Output cell start
+            code.line "__output__ << \"<td class=\\\"col\#{#{col_var}}\\\">\""
+
+            # Set loop variables
+            code.line "assigns[#{var_name.inspect}] = __item__"
+            code.line "assigns['tablerowloop'] = {"
+            code.indent do
+              code.line "'length' => #{len_var},"
+              code.line "'index' => #{idx_var} + 1,"
+              code.line "'index0' => #{idx_var},"
+              code.line "'rindex' => #{len_var} - #{idx_var},"
+              code.line "'rindex0' => #{len_var} - #{idx_var} - 1,"
+              code.line "'first' => #{idx_var} == 0,"
+              code.line "'last' => #{idx_var} == #{len_var} - 1,"
+              code.line "'col' => #{col_var},"
+              code.line "'col0' => #{col_var} - 1,"
+              code.line "'row' => #{row_var},"
+              code.line "'col_first' => #{col_var} == 1,"
+              code.line "'col_last' => #{col_var} == #{cols_var},"
+            end
+            code.line "}"
+
+            # Compile the body
+            BlockBodyCompiler.compile(body, compiler, code)
+
+            # Output cell end
+            code.line "__output__ << '</td>'"
+
+            # End row and start new row if needed (but not on last item)
+            code.line "if #{col_var} == #{cols_var} && #{idx_var} != #{len_var} - 1"
+            code.indent do
+              code.line "__output__ << \"</tr>\\n<tr class=\\\"row\#{#{row_var} + 1}\\\">\""
+              code.line "#{col_var} = 0"
+              code.line "#{row_var} += 1"
+            end
+            code.line "end"
+
+            code.line "#{idx_var} += 1"
+          end
+          code.line "end"
+
+          # Close the final row
+          code.line "__output__ << \"</tr>\\n\""
+
+          # Clean up
+          code.line "assigns.delete(#{var_name.inspect})"
+          code.line "assigns.delete('tablerowloop')"
+        end
+      end
+    end
+  end
+end

lib/liquid/compile/tags/unless_compiler.rb

@@ -0,0 +1,38 @@
+# frozen_string_literal: true
+
+module Liquid
+  module Compile
+    module Tags
+      # Compiles {% unless %} / {% elsif %} / {% else %} / {% endunless %} tags
+      #
+      # Unless is like if, but the first condition is negated
+      class UnlessCompiler
+        def self.compile(tag, compiler, code)
+          blocks = tag.blocks
+
+          blocks.each_with_index do |block, index|
+            condition_expr = ConditionCompiler.compile(block, compiler)
+
+            if index == 0
+              # First block is negated (unless = if not)
+              code.line "unless #{condition_expr}"
+            elsif block.else?
+              code.line "else"
+            else
+              # Subsequent blocks (elsif) are normal
+              code.line "elsif #{condition_expr}"
+            end
+
+            code.indent do
+              if block.attachment
+                BlockBodyCompiler.compile(block.attachment, compiler, code)
+              end
+            end
+          end
+
+          code.line "end"
+        end
+      end
+    end
+  end
+end

lib/liquid/compile/variable_compiler.rb

@@ -0,0 +1,37 @@
+# frozen_string_literal: true
+
+module Liquid
+  module Compile
+    # VariableCompiler compiles Liquid variable expressions ({{ ... }}) to Ruby code.
+    #
+    # A Variable consists of:
+    # - A name expression (the value to output)
+    # - Zero or more filters to apply
+    class VariableCompiler
+      # Compile a Variable node and append the result to the output buffer
+      # @param variable [Liquid::Variable] The variable node
+      # @param compiler [RubyCompiler] The main compiler instance
+      # @param code [CodeGenerator] The code generator
+      def self.compile(variable, compiler, code)
+        value_expr = compile_to_expression(variable, compiler)
+        code.line "__output__ << __output_value__(#{value_expr})"
+      end
+
+      # Compile a Variable node to a Ruby expression (without output)
+      # @param variable [Liquid::Variable] The variable node
+      # @param compiler [RubyCompiler] The main compiler instance
+      # @return [String] Ruby code expression
+      def self.compile_to_expression(variable, compiler)
+        # Compile the base name expression
+        base_expr = ExpressionCompiler.compile(variable.name, compiler)
+
+        # Apply filters if any
+        if variable.filters && !variable.filters.empty?
+          FilterCompiler.compile(base_expr, variable.filters, compiler)
+        else
+          base_expr
+        end
+      end
+    end
+  end
+end

lib/liquid/tags/doc.rb

@@ -36,8 +36,6 @@ module Liquid
     end
 
     def parse(tokens)
-      @body = +""
-
       while (token = tokens.shift)
         tag_name = token =~ BlockBody::FullTokenPossiblyInvalid && Regexp.last_match(2)
 
@@ -45,10 +43,8 @@ module Liquid
 
         if tag_name == block_delimiter
           parse_context.trim_whitespace = (token[-3] == WhitespaceControl)
-          @body << Regexp.last_match(1) if Regexp.last_match(1) != ""
           return
         end
-        @body << token unless token.empty?
       end
 
       raise_tag_never_closed(block_name)
@@ -59,11 +55,11 @@ module Liquid
     end
 
     def blank?
-      @body.empty?
+      true
     end
 
     def nodelist
-      [@body]
+      []
     end
 
     private

lib/liquid/template.rb

@@ -205,6 +205,63 @@ module Liquid
       render(context, output: output)
     end
 
+    # Compile the template to pure Ruby code.
+    #
+    # Returns a string containing Ruby code that can be eval'd to create
+    # a proc/lambda. The proc takes an assigns hash and returns the rendered
+    # output string.
+    #
+    # This provides a way to convert Liquid templates to standalone Ruby code
+    # that can be executed without the Liquid library at runtime.
+    #
+    # == Example
+    #
+    #   template = Liquid::Template.parse("Hello, {{ name }}!")
+    #   ruby_code = template.compile_to_ruby
+    #   render_proc = eval(ruby_code)
+    #   result = render_proc.call({ "name" => "World" })
+    #   # => "Hello, World!"
+    #
+    # == Options
+    #
+    # * <tt>:strict_variables</tt> - Raise on undefined variables (default: false)
+    # * <tt>:include_filters</tt> - Include helper methods for filters (default: true)
+    #
+    # == Advantages of Compiled Code
+    #
+    # * No Context object overhead
+    # * No filter invocation overhead (direct method calls)
+    # * No resource limits tracking
+    # * No stack-based scoping (uses Ruby's native scoping)
+    # * No profiling hooks
+    # * Direct string concatenation
+    #
+    # == Limitations
+    #
+    # * {% render %} and {% include %} tags require runtime support
+    # * Custom tags need explicit compiler implementations
+    # * Custom filters must be available at runtime
+    #
+    # Returns a CompiledTemplate object with the Ruby code and any external tags
+    # that need to be passed to the generated lambda.
+    #
+    # Usage:
+    #   compiled = template.compile_to_ruby
+    #   result = compiled.call({ "name" => "World" })  # Handles external tags automatically
+    #
+    # Or manually:
+    #   proc = eval(compiled.code)
+    #   result = proc.call(assigns, compiled.external_tags)
+    #
+    def compile_to_ruby(options = {})
+      return nil if @root.nil?
+
+      require 'liquid/compile'
+      compiler = Compile::RubyCompiler.new(self, options)
+      code = compiler.compile
+      Compile::CompiledTemplate.new(code, compiler.external_tags, compiler.has_external_filters?)
+    end
+
     private
 
     def configure_options(options)

lib/liquid/version.rb

@@ -2,5 +2,5 @@
 # frozen_string_literal: true
 
 module Liquid
-  VERSION = "5.8.7"
+  VERSION = "5.8.6"
 end

performance/compile_benchmark.rb

@@ -0,0 +1,222 @@
+# frozen_string_literal: true
+
+# Benchmark comparing compiled Ruby code vs interpreted Liquid rendering
+#
+# Usage:
+#   ruby performance/compile_benchmark.rb
+#
+# This benchmark compares:
+# 1. Standard Liquid render (interpreted)
+# 2. Compiled Ruby render (compiled once, executed many times)
+# 3. Compile + render (includes compilation overhead)
+
+require 'benchmark/ips'
+require_relative 'ruby33_compat'  # Add peek_byte for Ruby 3.3 compatibility
+require_relative 'shopify/liquid'
+require_relative 'shopify/database'
+
+RubyVM::YJIT.enable if defined?(RubyVM::YJIT)
+
+# Combined filter handler that includes all Shopify filters
+class ShopifyFilterHandler
+  include JsonFilter
+  include MoneyFilter
+  include ShopFilter
+  include TagFilter
+  include WeightFilter
+end
+
+class CompileBenchmarkRunner
+  def initialize
+    @templates = []
+    @compiled_procs = []
+    @filter_handler = ShopifyFilterHandler.new
+
+    # Load test templates
+    load_templates
+  end
+
+  def load_templates
+    puts "Loading templates..."
+
+    test_dirs = Dir[__dir__ + '/tests/*']
+    test_dirs.each do |dir|
+      next unless File.directory?(dir)
+
+      Dir[dir + '/*.liquid'].each do |file|
+        next if File.basename(file) == 'theme.liquid'
+
+        source = File.read(file)
+        template = Liquid::Template.parse(source)
+
+        @templates << {
+          name: File.basename(file),
+          source: source,
+          template: template,
+          assigns: Database.tables.dup,
+        }
+      end
+    end
+
+    puts "Loaded #{@templates.size} templates"
+
+    # Pre-compile all templates
+    puts "Pre-compiling templates to Ruby..."
+    @templates.each do |t|
+      begin
+        compiled = t[:template].compile_to_ruby
+        compiled.filter_handler = @filter_handler  # Set the filter handler
+        t[:compiled] = compiled  # CompiledTemplate object
+        t[:ruby_code] = compiled.code
+        notes = []
+        notes << "#{compiled.external_tags.size} external tag(s)" if compiled.has_external_tags?
+        notes << "external filters" if compiled.has_external_filters?
+        puts "  #{t[:name]}: #{notes.join(', ')}" unless notes.empty?
+      rescue => e
+        puts "  Warning: Failed to compile #{t[:name]}: #{e.message}"
+        puts "    #{e.backtrace.first(3).join("\n    ")}"
+        t[:compiled] = nil
+      end
+    end
+
+    compilable = @templates.count { |t| t[:compiled] }
+    puts "Successfully compiled #{compilable}/#{@templates.size} templates"
+    puts
+  end
+
+  # Benchmark: Standard Liquid render
+  def render_interpreted
+    @templates.each do |t|
+      t[:template].render!(t[:assigns].dup)
+    end
+  end
+
+  # Benchmark: Compiled Ruby render (already compiled)
+  def render_compiled
+    @templates.each do |t|
+      next unless t[:compiled]
+      t[:compiled].call(t[:assigns].dup)
+    end
+  end
+
+  # Benchmark: Compile + render (includes compilation time)
+  def compile_and_render
+    @templates.each do |t|
+      compiled = t[:template].compile_to_ruby
+      compiled.filter_handler = @filter_handler
+      compiled.call(t[:assigns].dup)
+    end
+  end
+
+  # Show sample output comparison
+  def verify_output
+    puts "Verifying output equivalence..."
+
+    @templates.each do |t|
+      next unless t[:compiled]
+
+      assigns = t[:assigns].dup
+      interpreted = t[:template].render!(assigns.dup)
+      compiled = t[:compiled].call(assigns.dup)
+
+      if interpreted == compiled
+        puts "  ✓ #{t[:name]}: outputs match"
+      else
+        puts "  ✗ #{t[:name]}: outputs differ!"
+        puts "    Interpreted length: #{interpreted.length}"
+        puts "    Compiled length: #{compiled.length}"
+
+        # Show first difference
+        interpreted.chars.each_with_index do |c, i|
+          if compiled[i] != c
+            puts "    First diff at position #{i}:"
+            puts "      Interpreted: #{interpreted[i-10, 30].inspect}"
+            puts "      Compiled: #{compiled[i-10, 30].inspect}"
+            break
+          end
+        end
+      end
+    end
+    puts
+  end
+
+  # Show code size comparison
+  def show_stats
+    puts "Template Statistics:"
+    puts "=" * 60
+
+    total_liquid_size = 0
+    total_ruby_size = 0
+
+    @templates.each do |t|
+      next unless t[:ruby_code]
+
+      liquid_size = t[:source].length
+      ruby_size = t[:ruby_code].length
+
+      total_liquid_size += liquid_size
+      total_ruby_size += ruby_size
+
+      ratio = ruby_size.to_f / liquid_size
+      puts "  #{t[:name]}: Liquid=#{liquid_size}b, Ruby=#{ruby_size}b (#{ratio.round(1)}x)"
+    end
+
+    puts "-" * 60
+    puts "  Total: Liquid=#{total_liquid_size}b, Ruby=#{total_ruby_size}b"
+    puts
+  end
+
+  def run_benchmark
+    puts "Running benchmark..."
+    puts "=" * 60
+    puts
+
+    # Run quick timing to get approximate values for summary
+    iterations = 50
+
+    start = Process.clock_gettime(Process::CLOCK_MONOTONIC)
+    iterations.times { render_interpreted }
+    interpreted_time = Process.clock_gettime(Process::CLOCK_MONOTONIC) - start
+
+    start = Process.clock_gettime(Process::CLOCK_MONOTONIC)
+    iterations.times { render_compiled }
+    compiled_time = Process.clock_gettime(Process::CLOCK_MONOTONIC) - start
+
+    speedup = interpreted_time / compiled_time
+
+    Benchmark.ips do |x|
+      x.time = 10
+      x.warmup = 5
+
+      x.report("Liquid render (interpreted):") do
+        render_interpreted
+      end
+
+      x.report("Ruby render (pre-compiled):") do
+        render_compiled
+      end
+
+      x.report("Compile + render:") do
+        compile_and_render
+      end
+
+      x.compare!
+    end
+
+    # Print clear summary
+    puts
+    puts "=" * 60
+    puts "SUMMARY:"
+    puts "  ✓ Pre-compiled Ruby is #{speedup.round(2)}x FASTER than interpreted Liquid"
+    puts
+    puts "  (The 'X slower' above means compared to the fastest option,"
+    puts "   which is pre-compiled Ruby. Higher i/s = faster.)"
+    puts "=" * 60
+  end
+end
+
+# Run the benchmark
+runner = CompileBenchmarkRunner.new
+runner.show_stats
+runner.verify_output
+runner.run_benchmark

performance/ruby33_compat.rb

@@ -0,0 +1,26 @@
+# frozen_string_literal: true
+
+# Compatibility shim for Ruby 3.3
+# The Liquid library uses peek_byte and scan_byte which are only available in Ruby 3.4+
+
+require 'strscan'
+
+unless StringScanner.method_defined?(:peek_byte)
+  class StringScanner
+    def peek_byte
+      return nil if eos?
+      string.getbyte(pos)
+    end
+  end
+end
+
+unless StringScanner.method_defined?(:scan_byte)
+  class StringScanner
+    def scan_byte
+      return nil if eos?
+      byte = string.getbyte(pos)
+      self.pos += 1
+      byte
+    end
+  end
+end

test/unit/compile_test.rb

@@ -0,0 +1,556 @@
+# frozen_string_literal: true
+
+require 'test_helper'
+
+# Ruby 3.3 compatibility for peek_byte and scan_byte
+require 'strscan'
+unless StringScanner.method_defined?(:peek_byte)
+  class StringScanner
+    def peek_byte
+      return nil if eos?
+      string.getbyte(pos)
+    end
+  end
+end
+
+unless StringScanner.method_defined?(:scan_byte)
+  class StringScanner
+    def scan_byte
+      return nil if eos?
+      byte = string.getbyte(pos)
+      self.pos += 1
+      byte
+    end
+  end
+end
+
+class CompileTest < Minitest::Test
+  include Liquid
+
+  def test_compile_simple_string
+    template = Template.parse("Hello, World!")
+    compiled = template.compile_to_ruby
+    assert_equal "Hello, World!", compiled.call({})
+  end
+
+  def test_compile_variable
+    template = Template.parse("Hello, {{ name }}!")
+    compiled = template.compile_to_ruby
+    assert_equal "Hello, World!", compiled.call({ "name" => "World" })
+  end
+
+  def test_compile_variable_with_filter
+    template = Template.parse("{{ name | upcase }}")
+    compiled = template.compile_to_ruby
+    assert_equal "WORLD", compiled.call({ "name" => "world" })
+  end
+
+  def test_compile_variable_with_multiple_filters
+    template = Template.parse("{{ name | downcase | capitalize }}")
+    compiled = template.compile_to_ruby
+    assert_equal "Hello", compiled.call({ "name" => "HELLO" })
+  end
+
+  def test_compile_if_true
+    template = Template.parse("{% if show %}visible{% endif %}")
+    compiled = template.compile_to_ruby
+    assert_equal "visible", compiled.call({ "show" => true })
+    assert_equal "", compiled.call({ "show" => false })
+  end
+
+  def test_compile_if_else
+    template = Template.parse("{% if show %}yes{% else %}no{% endif %}")
+    compiled = template.compile_to_ruby
+    assert_equal "yes", compiled.call({ "show" => true })
+    assert_equal "no", compiled.call({ "show" => false })
+  end
+
+  def test_compile_if_elsif
+    template = Template.parse("{% if x == 1 %}one{% elsif x == 2 %}two{% else %}other{% endif %}")
+    compiled = template.compile_to_ruby
+    assert_equal "one", compiled.call({ "x" => 1 })
+    assert_equal "two", compiled.call({ "x" => 2 })
+    assert_equal "other", compiled.call({ "x" => 3 })
+  end
+
+  def test_compile_unless
+    template = Template.parse("{% unless hidden %}visible{% endunless %}")
+    compiled = template.compile_to_ruby
+    assert_equal "visible", compiled.call({ "hidden" => false })
+    assert_equal "", compiled.call({ "hidden" => true })
+  end
+
+  def test_compile_for_loop
+    template = Template.parse("{% for item in items %}{{ item }} {% endfor %}")
+    compiled = template.compile_to_ruby
+    assert_equal "a b c ", compiled.call({ "items" => ["a", "b", "c"] })
+  end
+
+  def test_compile_for_loop_with_forloop
+    template = Template.parse("{% for item in items %}{{ forloop.index }}:{{ item }} {% endfor %}")
+    compiled = template.compile_to_ruby
+    assert_equal "1:a 2:b 3:c ", compiled.call({ "items" => ["a", "b", "c"] })
+  end
+
+  def test_compile_for_loop_else
+    template = Template.parse("{% for item in items %}{{ item }}{% else %}empty{% endfor %}")
+    compiled = template.compile_to_ruby
+    assert_equal "abc", compiled.call({ "items" => ["a", "b", "c"] })
+    assert_equal "empty", compiled.call({ "items" => [] })
+  end
+
+  def test_compile_for_with_limit
+    template = Template.parse("{% for item in items limit:2 %}{{ item }}{% endfor %}")
+    compiled = template.compile_to_ruby
+    assert_equal "ab", compiled.call({ "items" => ["a", "b", "c", "d"] })
+  end
+
+  def test_compile_assign
+    template = Template.parse("{% assign x = 'hello' %}{{ x }}")
+    compiled = template.compile_to_ruby
+    assert_equal "hello", compiled.call({})
+  end
+
+  def test_compile_assign_with_filter
+    template = Template.parse("{% assign x = name | upcase %}{{ x }}")
+    compiled = template.compile_to_ruby
+    assert_equal "WORLD", compiled.call({ "name" => "world" })
+  end
+
+  def test_compile_capture
+    template = Template.parse("{% capture greeting %}Hello, {{ name }}!{% endcapture %}{{ greeting }}")
+    compiled = template.compile_to_ruby
+    assert_equal "Hello, World!", compiled.call({ "name" => "World" })
+  end
+
+  def test_compile_case
+    template = Template.parse("{% case x %}{% when 1 %}one{% when 2 %}two{% else %}other{% endcase %}")
+    compiled = template.compile_to_ruby
+    assert_equal "one", compiled.call({ "x" => 1 })
+    assert_equal "two", compiled.call({ "x" => 2 })
+    assert_equal "other", compiled.call({ "x" => 3 })
+  end
+
+  def test_compile_raw
+    template = Template.parse("{% raw %}{{ not_a_variable }}{% endraw %}")
+    compiled = template.compile_to_ruby
+    assert_equal "{{ not_a_variable }}", compiled.call({})
+  end
+
+  def test_compile_comment
+    template = Template.parse("before{% comment %}hidden{% endcomment %}after")
+    compiled = template.compile_to_ruby
+    assert_equal "beforeafter", compiled.call({})
+  end
+
+  def test_compile_increment
+    template = Template.parse("{% increment x %}{% increment x %}{% increment x %}")
+    compiled = template.compile_to_ruby
+    assert_equal "012", compiled.call({})
+  end
+
+  def test_compile_decrement
+    template = Template.parse("{% decrement x %}{% decrement x %}{% decrement x %}")
+    compiled = template.compile_to_ruby
+    assert_equal "-1-2-3", compiled.call({})
+  end
+
+  def test_compile_cycle
+    template = Template.parse("{% for i in (1..3) %}{% cycle 'a', 'b' %}{% endfor %}")
+    compiled = template.compile_to_ruby
+    assert_equal "aba", compiled.call({})
+  end
+
+  def test_compile_nested_property_access
+    template = Template.parse("{{ user.profile.name }}")
+    compiled = template.compile_to_ruby
+    data = { "user" => { "profile" => { "name" => "Alice" } } }
+    assert_equal "Alice", compiled.call(data)
+  end
+
+  def test_compile_array_access
+    template = Template.parse("{{ items[1] }}")
+    compiled = template.compile_to_ruby
+    assert_equal "b", compiled.call({ "items" => ["a", "b", "c"] })
+  end
+
+  def test_compile_size_filter
+    template = Template.parse("{{ items | size }}")
+    compiled = template.compile_to_ruby
+    assert_equal "3", compiled.call({ "items" => [1, 2, 3] })
+  end
+
+  def test_compile_join_filter
+    template = Template.parse("{{ items | join: ', ' }}")
+    compiled = template.compile_to_ruby
+    assert_equal "a, b, c", compiled.call({ "items" => ["a", "b", "c"] })
+  end
+
+  def test_compile_split_filter
+    template = Template.parse("{% assign arr = str | split: ',' %}{{ arr | size }}")
+    compiled = template.compile_to_ruby
+    assert_equal "3", compiled.call({ "str" => "a,b,c" })
+  end
+
+  def test_compile_math_filters
+    template = Template.parse("{{ x | plus: 5 | minus: 2 | times: 3 }}")
+    compiled = template.compile_to_ruby
+    assert_equal "24", compiled.call({ "x" => 5 })
+  end
+
+  def test_compile_default_filter
+    template = Template.parse("{{ x | default: 'nothing' }}")
+    compiled = template.compile_to_ruby
+    assert_equal "hello", compiled.call({ "x" => "hello" })
+    assert_equal "nothing", compiled.call({ "x" => nil })
+    assert_equal "nothing", compiled.call({})
+  end
+
+  def test_compile_first_last_filters
+    template = Template.parse("{{ items | first }}-{{ items | last }}")
+    compiled = template.compile_to_ruby
+    assert_equal "a-c", compiled.call({ "items" => ["a", "b", "c"] })
+  end
+
+  def test_compile_escape_filter
+    template = Template.parse("{{ html | escape }}")
+    compiled = template.compile_to_ruby
+    assert_equal "&lt;p&gt;hello&lt;/p&gt;", compiled.call({ "html" => "<p>hello</p>" })
+  end
+
+  def test_compile_replace_filter
+    template = Template.parse("{{ str | replace: 'foo', 'bar' }}")
+    compiled = template.compile_to_ruby
+    assert_equal "bar baz bar", compiled.call({ "str" => "foo baz foo" })
+  end
+
+  def test_compile_append_prepend_filters
+    template = Template.parse("{{ name | prepend: 'Hello, ' | append: '!' }}")
+    compiled = template.compile_to_ruby
+    assert_equal "Hello, World!", compiled.call({ "name" => "World" })
+  end
+
+  def test_compile_for_break
+    template = Template.parse("{% for i in (1..5) %}{% if i == 3 %}{% break %}{% endif %}{{ i }}{% endfor %}")
+    compiled = template.compile_to_ruby
+    assert_equal "12", compiled.call({})
+  end
+
+  def test_compile_for_continue
+    template = Template.parse("{% for i in (1..5) %}{% if i == 3 %}{% continue %}{% endif %}{{ i }}{% endfor %}")
+    compiled = template.compile_to_ruby
+    assert_equal "1245", compiled.call({})
+  end
+
+  def test_compile_comparison_operators
+    template = Template.parse("{% if x > 5 %}big{% elsif x == 5 %}five{% else %}small{% endif %}")
+    compiled = template.compile_to_ruby
+    assert_equal "big", compiled.call({ "x" => 10 })
+    assert_equal "five", compiled.call({ "x" => 5 })
+    assert_equal "small", compiled.call({ "x" => 2 })
+  end
+
+  def test_compile_and_or_operators
+    template = Template.parse("{% if a and b %}both{% elsif a or b %}one{% else %}none{% endif %}")
+    compiled = template.compile_to_ruby
+    assert_equal "both", compiled.call({ "a" => true, "b" => true })
+    assert_equal "one", compiled.call({ "a" => true, "b" => false })
+    assert_equal "none", compiled.call({ "a" => false, "b" => false })
+  end
+
+  def test_compile_contains
+    template = Template.parse("{% if str contains 'hello' %}found{% else %}not found{% endif %}")
+    compiled = template.compile_to_ruby
+    assert_equal "found", compiled.call({ "str" => "say hello world" })
+    assert_equal "not found", compiled.call({ "str" => "goodbye" })
+  end
+
+  def test_compile_produces_valid_ruby
+    template = Template.parse("{% for item in items %}{{ item | upcase }}{% endfor %}")
+    compiled = template.compile_to_ruby
+
+    # Should produce valid Ruby syntax - if eval succeeds without error, it's valid
+    proc = eval(compiled.code)
+    assert_kind_of Proc, proc
+  end
+
+  def test_compile_vs_render_equivalence
+    templates = [
+      "Hello, {{ name }}!",
+      "{% if show %}visible{% else %}hidden{% endif %}",
+      "{% for i in (1..3) %}{{ i }}{% endfor %}",
+      "{{ str | upcase | split: '' | join: '-' }}",
+      "{% assign x = 5 %}{% assign y = x | plus: 3 %}{{ y }}",
+    ]
+
+    assigns_list = [
+      { "name" => "World", "show" => true, "str" => "hello" },
+      { "name" => "Ruby", "show" => false, "str" => "test" },
+    ]
+
+    templates.each do |source|
+      template = Template.parse(source)
+      compiled = template.compile_to_ruby
+
+      assigns_list.each do |assigns|
+        expected = template.render(assigns)
+        actual = compiled.call(assigns.dup)
+        assert_equal expected, actual, "Mismatch for template '#{source}' with assigns #{assigns}"
+      end
+    end
+  end
+
+  def test_compiled_template_class
+    template = Template.parse("Hello, {{ name }}!")
+    compiled = template.compile_to_ruby
+
+    assert_instance_of Liquid::Compile::CompiledTemplate, compiled
+    assert_respond_to compiled, :call
+    assert_respond_to compiled, :code
+    assert_respond_to compiled, :to_s
+    assert_respond_to compiled, :to_proc
+  end
+
+  def test_compiled_template_code
+    template = Template.parse("Hello!")
+    compiled = template.compile_to_ruby
+
+    assert_kind_of String, compiled.code
+    assert_includes compiled.code, "__output__"
+    assert_includes compiled.code, "Hello!"
+  end
+
+  def test_external_tags_indicator
+    # A simple template should have no external tags
+    template = Template.parse("Hello!")
+    compiled = template.compile_to_ruby
+
+    assert_equal false, compiled.has_external_tags?
+    assert_empty compiled.external_tags
+  end
+
+  def test_external_filters_indicator
+    # A simple template should have no external filters
+    template = Template.parse("{{ name | upcase }}")
+    compiled = template.compile_to_ruby
+
+    assert_equal false, compiled.has_external_filters?
+  end
+
+  def test_comprehensive_output_equivalence
+    # Comprehensive test comparing compiled vs interpreted output
+    test_cases = [
+      # Basic variables
+      { source: "{{ x }}", assigns: { "x" => "hello" } },
+      { source: "{{ x }}", assigns: { "x" => 123 } },
+      { source: "{{ x }}", assigns: { "x" => nil } },
+
+      # Nested access
+      { source: "{{ a.b.c }}", assigns: { "a" => { "b" => { "c" => "deep" } } } },
+      { source: "{{ items[0] }}", assigns: { "items" => ["first", "second"] } },
+
+      # Filters
+      { source: "{{ x | upcase }}", assigns: { "x" => "hello" } },
+      { source: "{{ x | size }}", assigns: { "x" => [1, 2, 3] } },
+      { source: "{{ x | default: 'fallback' }}", assigns: { "x" => nil } },
+      { source: "{{ x | plus: 10 }}", assigns: { "x" => 5 } },
+      { source: "{{ x | split: ',' | first }}", assigns: { "x" => "a,b,c" } },
+
+      # Conditionals
+      { source: "{% if x %}yes{% endif %}", assigns: { "x" => true } },
+      { source: "{% if x %}yes{% endif %}", assigns: { "x" => false } },
+      { source: "{% if x > 5 %}big{% else %}small{% endif %}", assigns: { "x" => 10 } },
+
+      # Loops
+      { source: "{% for i in items %}{{ i }}{% endfor %}", assigns: { "items" => [1, 2, 3] } },
+      { source: "{% for i in (1..3) %}{{ i }}{% endfor %}", assigns: {} },
+      { source: "{% for i in items %}{{ forloop.index }}{% endfor %}", assigns: { "items" => %w[a b] } },
+      { source: "{% for i in items %}{% if forloop.first %}first{% endif %}{% endfor %}", assigns: { "items" => [1, 2] } },
+
+      # Assignments
+      { source: "{% assign y = x | upcase %}{{ y }}", assigns: { "x" => "hello" } },
+      { source: "{% capture c %}Hello {{ x }}{% endcapture %}{{ c }}", assigns: { "x" => "World" } },
+
+      # Case
+      { source: "{% case x %}{% when 1 %}one{% when 2 %}two{% else %}other{% endcase %}", assigns: { "x" => 1 } },
+      { source: "{% case x %}{% when 1 %}one{% when 2 %}two{% else %}other{% endcase %}", assigns: { "x" => 3 } },
+
+      # Increment/Decrement
+      { source: "{% increment x %}{% increment x %}", assigns: {} },
+      { source: "{% decrement x %}{% decrement x %}", assigns: {} },
+
+      # Cycle
+      { source: "{% for i in (1..4) %}{% cycle 'a', 'b' %}{% endfor %}", assigns: {} },
+
+      # Break/Continue
+      { source: "{% for i in (1..5) %}{% if i == 3 %}{% break %}{% endif %}{{ i }}{% endfor %}", assigns: {} },
+      { source: "{% for i in (1..5) %}{% if i == 3 %}{% continue %}{% endif %}{{ i }}{% endfor %}", assigns: {} },
+
+      # Raw
+      { source: "{% raw %}{{ not a var }}{% endraw %}", assigns: {} },
+
+      # Comment
+      { source: "before{% comment %}hidden{% endcomment %}after", assigns: {} },
+
+      # Tablerow
+      { source: "{% tablerow i in items cols:2 %}{{ i }}{% endtablerow %}", assigns: { "items" => [1, 2, 3] } },
+    ]
+
+    test_cases.each do |tc|
+      source = tc[:source]
+      assigns = tc[:assigns]
+
+      template = Template.parse(source)
+      compiled = template.compile_to_ruby
+
+      expected = template.render(assigns.dup)
+      actual = compiled.call(assigns.dup)
+
+      assert_equal expected, actual, "Output mismatch for: #{source.inspect}\nAssigns: #{assigns.inspect}"
+    end
+  end
+
+  def test_debug_mode_adds_comments
+    template = Template.parse("{{ name }}")
+    compiled = template.compile_to_ruby(debug: true)
+
+    assert_includes compiled.code, "# LIQUID"
+    assert_includes compiled.code, "# Compiled from Liquid template"
+  end
+
+  def test_filter_handler_can_be_set
+    # Create a custom filter module
+    filter_mod = Module.new do
+      def custom_filter(input)
+        "custom:#{input}"
+      end
+    end
+
+    class_with_filter = Class.new do
+      include filter_mod
+    end
+
+    template = Template.parse("{{ x | custom_filter }}")
+    compiled = template.compile_to_ruby
+    compiled.filter_handler = class_with_filter.new
+
+    # The template should use the custom filter
+    result = compiled.call({ "x" => "test" })
+    assert_equal "custom:test", result
+  end
+
+  # Test Drop support
+  def test_compile_with_drop
+    # Create a simple Drop class
+    product_drop = Class.new(Liquid::Drop) do
+      def initialize(name, price)
+        super()
+        @name = name
+        @price = price
+      end
+
+      def name
+        @name
+      end
+
+      def price
+        @price
+      end
+
+      def discounted_price
+        @price * 0.9
+      end
+    end
+
+    template = Template.parse("Product: {{ product.name }} costs ${{ product.price }}")
+    compiled = template.compile_to_ruby
+
+    drop = product_drop.new("Widget", 100)
+    result = compiled.call({ "product" => drop })
+    assert_equal "Product: Widget costs $100", result
+  end
+
+  def test_compile_with_drop_context_access
+    # Create a Drop that uses context
+    context_aware_drop = Class.new(Liquid::Drop) do
+      def initialize(multiplier)
+        super()
+        @multiplier = multiplier
+      end
+
+      def computed_value
+        # Access another variable via context
+        base = @context["base_value"] || 0
+        base * @multiplier
+      end
+    end
+
+    template = Template.parse("Result: {{ calc.computed_value }}")
+    compiled = template.compile_to_ruby
+
+    drop = context_aware_drop.new(3)
+    result = compiled.call({ "calc" => drop, "base_value" => 10 })
+    assert_equal "Result: 30", result
+  end
+
+  def test_compile_with_nested_drops
+    inner_drop = Class.new(Liquid::Drop) do
+      def initialize(value)
+        super()
+        @value = value
+      end
+
+      def value
+        @value
+      end
+    end
+
+    outer_drop = Class.new(Liquid::Drop) do
+      def initialize(inner)
+        super()
+        @inner = inner
+      end
+
+      def inner
+        @inner
+      end
+    end
+
+    template = Template.parse("{{ outer.inner.value }}")
+    compiled = template.compile_to_ruby
+
+    inner = inner_drop.new("nested!")
+    outer = outer_drop.new(inner)
+    result = compiled.call({ "outer" => outer })
+    assert_equal "nested!", result
+  end
+
+  def test_compile_with_forloop_drop
+    # ForloopDrop is a built-in Drop - ensure it works
+    template = Template.parse("{% for item in items %}{{ forloop.index }}:{{ item }} {% endfor %}")
+    compiled = template.compile_to_ruby
+
+    # Note: Compiled code uses a hash for forloop, not the actual ForloopDrop
+    # This test verifies the hash-based forloop still works
+    result = compiled.call({ "items" => ["a", "b", "c"] })
+    assert_equal "1:a 2:b 3:c ", result
+  end
+
+  def test_compile_with_registers
+    template = Template.parse("{{ product.name }}")
+    compiled = template.compile_to_ruby
+
+    # Create a Drop that checks registers
+    product_drop = Class.new(Liquid::Drop) do
+      def name
+        # Access registers through context
+        store = @context.registers[:store] || "Unknown Store"
+        "Product from #{store}"
+      end
+    end
+
+    drop = product_drop.new
+    result = compiled.call({ "product" => drop }, registers: { store: "Acme Corp" })
+    assert_equal "Product from Acme Corp", result
+  end
+end

test/unit/environment_test.rb

@@ -1,25 +0,0 @@
-# frozen_string_literal: true
-
-require 'test_helper'
-
-class EnvironmentTest < Minitest::Test
-  include Liquid
-
-  class UnsubscribeFooter < Liquid::Tag
-    def render(_context)
-      'Unsubscribe Footer'
-    end
-  end
-
-  def test_custom_tag
-    email_environment = Liquid::Environment.build do |environment|
-      environment.register_tag("unsubscribe_footer", UnsubscribeFooter)
-    end
-
-    assert(email_environment.tags["unsubscribe_footer"])
-    assert(email_environment.tag_for_name("unsubscribe_footer"))
-    template = Liquid::Template.parse("{% unsubscribe_footer %}", environment: email_environment)
-
-    assert_equal('Unsubscribe Footer', template.render)
-  end
-end

test/unit/tags/doc_tag_unit_test.rb

@@ -20,21 +20,6 @@ class DocTagUnitTest < Minitest::Test
     assert_template_result('', template)
   end
 
-  def test_doc_tag_body_content
-    doc_content = "  Documentation content\n  @param {string} foo - test\n"
-    template_source = "{% doc %}#{doc_content}{% enddoc %}"
-
-    doc_tag = nil
-    ParseTreeVisitor
-      .for(Template.parse(template_source).root)
-      .add_callback_for(Liquid::Doc) do |tag|
-        doc_tag = tag
-      end
-      .visit
-
-    assert_equal(doc_content, doc_tag.nodelist.first.to_s)
-  end
-
   def test_doc_tag_does_not_support_extra_arguments
     error = assert_raises(Liquid::SyntaxError) do
       template = <<~LIQUID.chomp
@@ -131,20 +116,6 @@ class DocTagUnitTest < Minitest::Test
     assert_template_result('', template)
   end
 
-  def test_doc_tag_captures_token_before_enddoc
-    template_source = "{% doc %}{{ incomplete{% enddoc %}"
-
-    doc_tag = nil
-    ParseTreeVisitor
-      .for(Template.parse(template_source).root)
-      .add_callback_for(Liquid::Doc) do |tag|
-        doc_tag = tag
-      end
-      .visit
-
-    assert_equal("{{ incomplete", doc_tag.nodelist.first.to_s)
-  end
-
   def test_doc_tag_preserves_error_line_numbers
     template = Liquid::Template.parse(<<~LIQUID.chomp, line_numbers: true)
       {% doc %}
@@ -174,11 +145,11 @@ class DocTagUnitTest < Minitest::Test
 
   def test_doc_tag_delimiter_handling
     assert_template_result('', <<~LIQUID.chomp)
-      {%- if true -%}
-        {%- doc -%}
-          {%- docEXTRA -%}wut{% enddocEXTRA -%}xyz
-        {%- enddoc -%}
-      {%- endif -%}
+      {% if true %}
+        {% doc %}
+          {% docEXTRA %}wut{% enddocEXTRA %}xyz
+        {% enddoc %}
+      {% endif %}
     LIQUID
 
     assert_template_result('', "{% doc %}123{% enddoc xyz %}")
@@ -196,80 +167,6 @@ class DocTagUnitTest < Minitest::Test
     )
   end
 
-  def test_doc_tag_blank_with_empty_content
-    template_source = "{% doc %}{% enddoc %}"
-
-    doc_tag = nil
-    ParseTreeVisitor
-      .for(Template.parse(template_source).root)
-      .add_callback_for(Liquid::Doc) do |tag|
-        doc_tag = tag
-      end
-      .visit
-
-    assert_equal(true, doc_tag.blank?)
-  end
-
-  def test_doc_tag_blank_with_content
-    template_source = "{% doc %}Some documentation{% enddoc %}"
-
-    doc_tag = nil
-    ParseTreeVisitor
-      .for(Template.parse(template_source).root)
-      .add_callback_for(Liquid::Doc) do |tag|
-        doc_tag = tag
-      end
-      .visit
-
-    assert_equal(false, doc_tag.blank?)
-  end
-
-  def test_doc_tag_blank_with_whitespace_only
-    template_source = "{% doc %}    {% enddoc %}"
-
-    doc_tag = nil
-    ParseTreeVisitor
-      .for(Template.parse(template_source).root)
-      .add_callback_for(Liquid::Doc) do |tag|
-        doc_tag = tag
-      end
-      .visit
-
-    assert_equal(false, doc_tag.blank?)
-  end
-
-  def test_doc_tag_nodelist_returns_array_with_body
-    doc_content = "Documentation content\n@param {string} foo"
-    template_source = "{% doc %}#{doc_content}{% enddoc %}"
-
-    doc_tag = nil
-    ParseTreeVisitor
-      .for(Template.parse(template_source).root)
-      .add_callback_for(Liquid::Doc) do |tag|
-        doc_tag = tag
-      end
-      .visit
-
-    assert_equal([doc_content], doc_tag.nodelist)
-    assert_equal(1, doc_tag.nodelist.length)
-    assert_equal(doc_content, doc_tag.nodelist.first)
-  end
-
-  def test_doc_tag_nodelist_with_empty_content
-    template_source = "{% doc %}{% enddoc %}"
-
-    doc_tag = nil
-    ParseTreeVisitor
-      .for(Template.parse(template_source).root)
-      .add_callback_for(Liquid::Doc) do |tag|
-        doc_tag = tag
-      end
-      .visit
-
-    assert_equal([""], doc_tag.nodelist)
-    assert_equal(1, doc_tag.nodelist.length)
-  end
-
   private
 
   def traversal(template)