refactor: Tag class support in registerTag()

docs/source/tutorials/register-filters-tags.md

@@ -12,8 +12,8 @@ engine.registerTag('upper', {
     parse: function(tagToken: TagToken, remainTokens: TopLevelToken[]) {
         this.str = tagToken.args; // name
     },
-    render: async function(ctx: Context) {
-        var str = await this.liquid.evalValue(this.str, ctx); // 'alice'
+    render: function*(ctx: Context) {
+        const str = yield this.liquid.evalValue(this.str, ctx); // 'alice'
         return str.toUpperCase() // 'ALICE'
     }
 });
@@ -22,6 +22,25 @@ engine.registerTag('upper', {
 * `parse`: Read tokens from `remainTokens` until your end token.
 * `render`: Combine scope data with your parsed tokens into HTML string.
 
+For complex tag implementation, you can also provide a tag class:
+
+```typescript
+// Usage: {% upper name:"alice" %}
+import { Hash, Tag, TagToken, Context, Emitter, TopLevelToken, Liquid } from 'liquidjs'
+
+engine.registerTag('upper', class UpperTag extends Tag {
+    private hash: Hash
+    constructor(tagToken: TagToken, remainTokens: TopLevelToken[], liquid: Liquid) {
+        super(tagToken, remainTokens, liquid)
+        this.hash = new Hash(tagToken.args)
+    }
+    * render(ctx: Context) {
+        const hash = yield this.hash.render();
+        return hash.name.toUpperCase() // 'ALICE'
+    }
+});
+```
+
 See existing tag implementations here: <https://github.com/harttle/liquidjs/tree/master/src/builtin/tags>
 See demo example here: https://github.com/harttle/liquidjs/blob/master/demo/typescript/index.ts
 

docs/source/zh-cn/tutorials/register-filters-tags.md

@@ -36,7 +36,24 @@ engine.registerFilter('upper', v => v.toUpperCase())
 engine.registerFilter('add', (initial, arg1, arg2) => initial + arg1 + arg2)
 ```
 
-查看已有的过滤器实现：<https://github.com/harttle/liquidjs/tree/master/src/builtin/filters>
+查看已有的过滤器实现：<https://github.com/harttle/liquidjs/tree/master/src/builtin/filters>。对于复杂的标签，也可以用一个类来实现：
+
+```typescript
+// Usage: {% upper name:"alice" %}
+import { Hash, Tag, TagToken, Context, Emitter, TopLevelToken, Liquid } from 'liquidjs'
+
+engine.registerTag('upper', class UpperTag extends Tag {
+    private hash: Hash
+    constructor(tagToken: TagToken, remainTokens: TopLevelToken[], liquid: Liquid) {
+        super(tagToken, remainTokens, liquid)
+        this.hash = new Hash(tagToken.args)
+    }
+    * render(ctx: Context) {
+        const hash = yield this.hash.render();
+        return hash.name.toUpperCase() // 'ALICE'
+    }
+});
+```
 
 ## 反注册标签/过滤器
 

package.json

@@ -9,7 +9,7 @@
     "./dist/liquid.node.cjs.js": "./dist/liquid.browser.umd.js",
     "./dist/liquid.node.esm.js": "./dist/liquid.browser.esm.js"
   },
-  "types": "dist/liquid.d.ts",
+  "types": "dist/index.d.ts",
   "engines": {
     "node": ">=14"
   },
@@ -44,9 +44,6 @@
     "LICENSE",
     "README.md"
   ],
-  "engines": {
-    "node": ">=4.8.7"
-  },
   "keywords": [
     "liquid",
     "template engine",

rollup.config.mjs

@@ -38,16 +38,16 @@ const versionInjection = versionInjector({
   logger: console,
   exclude: []
 })
-const input = './src/liquid.ts'
+const input = './src/index.ts'
 const browserFS = {
   include: './src/liquid-options.ts',
   delimiters: ['', ''],
   './fs/node': './fs/browser'
 }
 const browserStream = {
-  include: './src/render/render.ts',
+  include: './src/emitters/index.ts',
   delimiters: ['', ''],
-  '../emitters/streamed-emitter': '../emitters/streamed-emitter-browser'
+  './streamed-emitter': './streamed-emitter-browser'
 }
 const esmRequire = {
   include: './src/fs/node.ts',

src/cache/index.ts

@@ -0,0 +1,2 @@
+export * from './cache'
+export * from './lru'

src/cache/lru.ts

@@ -10,7 +10,7 @@ class Node<T> {
 }
 
 export class LRU<T> implements Cache<T> {
-  private cache: { [key: string]: Node<T> } = {}
+  private cache: Record<string, Node<T>> = {}
   private head: Node<T>
   private tail: Node<T>
 

src/context/block-mode.ts

@@ -1,8 +1,6 @@
-enum BlockMode {
+export enum BlockMode {
   /* store rendered html into blocks */
   OUTPUT,
   /* output rendered html directly */
   STORE
 }
-
-export default BlockMode

src/context/context.ts

@@ -2,9 +2,7 @@ import { Drop } from '../drop/drop'
 import { __assign } from 'tslib'
 import { NormalizedFullOptions, defaultOptions, RenderOptions } from '../liquid-options'
 import { Scope } from './scope'
-import { isArray, isNil, isString, isFunction, toLiquid } from '../util/underscore'
-import { InternalUndefinedVariableError } from '../util/error'
-import { toValueSync } from '../util/async'
+import { isArray, isNil, isString, isFunction, toLiquid, InternalUndefinedVariableError, toValueSync } from '../util'
 
 type PropertyKey = string | number;
 

src/context/index.ts

@@ -0,0 +1,3 @@
+export * from './context'
+export * from './scope'
+export * from './block-mode'

src/context/scope.ts

@@ -1,8 +1,7 @@
 import { Drop } from '../drop/drop'
 
-export interface PlainObject {
-  [key: string]: any;
+interface ScopeObject extends Record<string, any> {
   toLiquid?: () => any;
 }
 
-export type Scope = PlainObject | Drop
+export type Scope = ScopeObject | Drop

src/drop/blank-drop.ts

@@ -1,5 +1,5 @@
-import { isNil, isString, toValue } from '../util/underscore'
-import { EmptyDrop } from '../drop/empty-drop'
+import { isNil, isString, toValue } from '../util'
+import { EmptyDrop } from '../drop'
 
 export class BlankDrop extends EmptyDrop {
   public equals (value: any) {

src/drop/comparable.ts

@@ -1,4 +1,4 @@
-import { isFunction } from '../util/underscore'
+import { isFunction } from '../util'
 
 export interface Comparable {
   equals: (rhs: any) => boolean;

src/drop/empty-drop.ts

@@ -1,6 +1,6 @@
 import { Drop } from './drop'
 import { Comparable } from './comparable'
-import { isObject, isString, isArray, toValue } from '../util/underscore'
+import { isObject, isString, isArray, toValue } from '../util'
 
 export class EmptyDrop extends Drop implements Comparable {
   public equals (value: any) {

src/drop/index.ts

@@ -0,0 +1,7 @@
+export * from './drop'
+export * from './null-drop'
+export * from './empty-drop'
+export * from './blank-drop'
+export * from './forloop-drop'
+export * from './block-drop'
+export * from './comparable'

src/drop/null-drop.ts

@@ -1,6 +1,6 @@
 import { Drop } from './drop'
 import { Comparable } from './comparable'
-import { isNil, toValue } from '../util/underscore'
+import { isNil, toValue } from '../util'
 
 export class NullDrop extends Drop implements Comparable {
   public equals (value: any) {

src/emitters/index.ts

@@ -0,0 +1,4 @@
+export * from './emitter'
+export * from './simple-emitter'
+export * from './streamed-emitter'
+export * from './keeping-type-emitter'

src/emitters/keeping-type-emitter.ts

@@ -1,5 +1,5 @@
-import { stringify, toValue } from '../util/underscore'
-import { Emitter } from '../types'
+import { stringify, toValue } from '../util'
+import { Emitter } from './emitter'
 
 export class KeepingTypeEmitter implements Emitter {
   public buffer: any = '';

src/emitters/simple-emitter.ts

@@ -1,4 +1,4 @@
-import { stringify } from '../util/underscore'
+import { stringify } from '../util'
 import { Emitter } from './emitter'
 
 export class SimpleEmitter implements Emitter {

src/emitters/streamed-emitter.ts

@@ -1,4 +1,4 @@
-import { stringify } from '../util/underscore'
+import { stringify } from '../util'
 import { Emitter } from './emitter'
 import { PassThrough } from 'stream'
 

src/filters/array.ts

@@ -1,9 +1,8 @@
-import { argumentsToValue, toValue, stringify, caseInsensitiveCompare, isArray, isNil, last as arrayLast, hasOwnProperty } from '../util/underscore'
-import { toArray } from '../util/collection'
-import { isTruthy } from '../render/boolean'
-import { FilterImpl } from '../template/filter/filter-impl'
-import { Scope } from '../context/scope'
-import { isComparable } from '../drop/comparable'
+import { toArray, argumentsToValue, toValue, stringify, caseInsensitiveCompare, isArray, isNil, last as arrayLast, hasOwnProperty } from '../util'
+import { isTruthy } from '../render'
+import { FilterImpl } from '../template'
+import { Scope } from '../context'
+import { isComparable } from '../drop'
 
 export const join = argumentsToValue((v: any[], arg: string) => toArray(v).join(arg === undefined ? ' ' : arg))
 export const last = argumentsToValue((v: any) => isArray(v) ? arrayLast(v) : '')

src/filters/date.ts

@@ -1,8 +1,5 @@
-import strftime from '../util/strftime'
-import { LiquidDate } from '../util/liquid-date'
-import { toValue, stringify, isString, isNumber } from '../util/underscore'
-import { FilterImpl } from '../template/filter/filter-impl'
-import { TimezoneDate } from '../util/timezone-date'
+import { toValue, stringify, isString, isNumber, TimezoneDate, LiquidDate, strftime } from '../util'
+import { FilterImpl } from '../template'
 
 export function date (this: FilterImpl, v: string | Date, format: string, timeZoneOffset?: number) {
   const opts = this.context.opts

src/filters/index.ts

@@ -5,9 +5,9 @@ import * as arrayFilters from './array'
 import * as dateFilters from './date'
 import * as stringFilters from './string'
 import { Default, json } from './misc'
-import { FilterImplOptions } from '../template/filter/filter-impl-options'
+import { FilterImplOptions } from '../template'
 
-export const filters: { [key: string]: FilterImplOptions } = {
+export const filters: Record<string, FilterImplOptions> = {
   ...htmlFilters,
   ...mathFilters,
   ...urlFilters,

src/filters/misc.ts

@@ -1,6 +1,6 @@
 import { isFalsy } from '../render/boolean'
 import { identify, isArray, isString, toValue } from '../util/underscore'
-import { FilterImpl } from '../template/filter/filter-impl'
+import { FilterImpl } from '../template'
 
 export function Default<T1 extends boolean, T2> (this: FilterImpl, value: T1, defaultValue: T2, ...args: Array<[string, any]>): T1 | T2 {
   value = toValue(value)

src/filters/string.ts

@@ -3,8 +3,7 @@
  *
  * * prefer stringify() to String() since `undefined`, `null` should eval ''
  */
-import { escapeRegExp, stringify } from '../util/underscore'
-import { assert } from '../util/assert'
+import { assert, escapeRegExp, stringify } from '../util'
 
 export function append (v: string, arg: string) {
   assert(arguments.length === 2, 'append expect 2 arguments')

src/fs/browser.ts

@@ -1,4 +1,4 @@
-import { last } from '../util/underscore'
+import { last } from '../util'
 
 function domResolve (root: string, path: string) {
   const base = document.createElement('base')

src/fs/index.ts

@@ -0,0 +1,2 @@
+export * from './loader'
+export * from './fs'

src/fs/loader.ts

@@ -1,6 +1,5 @@
 import { FS } from './fs'
-import { escapeRegex } from '../util/underscore'
-import { assert } from '../util/assert'
+import { assert, escapeRegex } from '../util'
 
 export interface LoaderOptions {
   fs: FS;

src/fs/node.ts

@@ -1,10 +1,10 @@
-import * as _ from '../util/underscore'
+import { promisify } from '../util'
 import { sep, resolve as nodeResolve, extname, dirname as nodeDirname } from 'path'
 import { stat, statSync, readFile as nodeReadFile, readFileSync as nodeReadFileSync } from 'fs'
 import { requireResolve } from './node-require'
 
-const statAsync = _.promisify(stat)
-const readFileAsync = _.promisify<string, string, string>(nodeReadFile)
+const statAsync = promisify(stat)
+const readFileAsync = promisify<string, string, string>(nodeReadFile)
 
 export async function exists (filepath: string) {
   try {

src/index.ts

@@ -0,0 +1,16 @@
+/* istanbul ignore file */
+export const version = '[VI]{version}[/VI]'
+export * as TypeGuards from './util/type-guards'
+export { toValue, TimezoneDate, createTrie, Trie, toPromise, toValueSync, assert, ParseError, TokenizationError, AssertionError } from './util'
+export { Drop } from './drop'
+export { Emitter } from './emitters'
+// TODO change to _evalToken
+export { defaultOperators, Operators, _evalToken, evalQuotedToken, Expression, isFalsy, isTruthy } from './render'
+export { Context, Scope } from './context'
+export { Value, Hash, Template, FilterImplOptions, Tag, Filter } from './template'
+export { Token, TopLevelToken, TagToken, ValueToken } from './tokens'
+export { TokenKind, Tokenizer, ParseStream } from './parser'
+export { filters } from './filters'
+export { tags } from './tags'
+export { defaultOptions } from './liquid-options'
+export { Liquid } from './liquid'

src/liquid-options.ts

@@ -1,11 +1,9 @@
-import { isArray, isString, isFunction } from './util/underscore'
-import { LiquidCache } from './cache/cache'
-import { LRU } from './cache/lru'
+import { assert, isArray, isString, isFunction } from './util'
+import { LRU, LiquidCache } from './cache'
 import { FS } from './fs/fs'
 import * as fs from './fs/node'
-import { defaultOperators, Operators } from './render/operator'
+import { defaultOperators, Operators } from './render'
 import { filters } from './filters'
-import { assert } from './util/assert'
 
 type OutputEscape = (value: any) => string
 type OutputEscapeOption = 'escape' | 'json' | OutputEscape

src/liquid.ts

@@ -1,38 +1,24 @@
-import { Context } from './context/context'
-import { forOwn } from './util/underscore'
-import { Template } from './template/template'
+import { Context } from './context'
+import { toPromise, toValueSync, isFunction, forOwn } from './util'
+import { TagClass, createTagClass, TagImplOptions, FilterImplOptions, Template, Value } from './template'
 import { LookupType } from './fs/loader'
-import { Render } from './render/render'
-import Parser from './parser/parser'
-import { TagImplOptions } from './template/tag/tag-impl-options'
-import { Value } from './template/value'
+import { Render } from './render'
+import { Parser } from './parser'
 import { tags } from './tags'
 import { filters } from './filters'
-import { TagMap } from './template/tag/tag-map'
-import { FilterMap } from './template/filter/filter-map'
 import { LiquidOptions, normalizeDirectoryList, NormalizedFullOptions, normalize, RenderOptions } from './liquid-options'
-import { FilterImplOptions } from './template/filter/filter-impl-options'
-import { toPromise, toValueSync } from './util/async'
-
-export * from './util/error'
-export * from './types'
-export const version = '[VI]{version}[/VI]'
 
 export class Liquid {
   public readonly options: NormalizedFullOptions
-  public readonly renderer: Render
+  public readonly renderer = new Render()
   public readonly parser: Parser
-  public readonly filters: FilterMap
-  public readonly tags: TagMap
+  public readonly filters: Record<string, FilterImplOptions> = {}
+  public readonly tags: Record<string, TagClass> = {}
 
   public constructor (opts: LiquidOptions = {}) {
     this.options = normalize(opts)
     this.parser = new Parser(this)
-    this.renderer = new Render()
-    this.filters = new FilterMap(this.options.strictFilters, this)
-    this.tags = new TagMap()
-
-    forOwn(tags, (conf: TagImplOptions, name: string) => this.registerTag(name, conf))
+    forOwn(tags, (conf: TagClass, name: string) => this.registerTag(name, conf))
     forOwn(filters, (handler: FilterImplOptions, name: string) => this.registerFilter(name, handler))
   }
   public parse (html: string, filepath?: string): Template[] {
@@ -103,10 +89,10 @@ export class Liquid {
   }
 
   public registerFilter (name: string, filter: FilterImplOptions) {
-    this.filters.set(name, filter)
+    this.filters[name] = filter
   }
-  public registerTag (name: string, tag: TagImplOptions) {
-    this.tags.set(name, tag)
+  public registerTag (name: string, tag: TagClass | TagImplOptions) {
+    this.tags[name] = isFunction(tag) ? tag : createTagClass(tag)
   }
   public plugin (plugin: (this: Liquid, L: typeof Liquid) => void) {
     return plugin.call(this, Liquid)

src/parser/filter-arg.ts

@@ -5,6 +5,6 @@ type KeyValuePair = [string?, ValueToken?]
 
 export type FilterArg = ValueToken | KeyValuePair
 
-export function isKeyValuePair (arr: FilterArg): arr is KeyValuePair { // TODO check
+export function isKeyValuePair (arr: FilterArg): arr is KeyValuePair {
   return isArray(arr)
 }

src/parser/index.ts

@@ -0,0 +1,5 @@
+export * from './tokenizer'
+export * from './parser'
+export * from './parse-stream'
+export * from './parse-string-literal'
+export * from './token-kind'

src/parser/match-operator.ts

@@ -1,8 +1,7 @@
-import { IDENTIFIER, TYPES } from '../util/character'
-import { Trie } from '../util/operator-trie'
+import { Trie, TrieNode, IDENTIFIER, TYPES } from '../util'
 
 export function matchOperator (str: string, begin: number, trie: Trie, end = str.length) {
-  let node = trie
+  let node: TrieNode = trie
   let i = begin
   let info
   while (node[str[i]] && i < end) {

src/parser/parse-stream.ts

@@ -1,13 +1,12 @@
-import { Token } from '../tokens/token'
-import { Template } from '../template/template'
-import { isTagToken } from '../util/type-guards'
-import { TopLevelToken } from '../tokens/toplevel-token'
+import { Token, TopLevelToken } from '../tokens'
+import { Template } from '../template'
+import { isTagToken } from '../util'
 
 type ParseToken<T extends Token> = ((token: T, remainTokens: T[]) => Template)
 
 export class ParseStream<T extends Token = TopLevelToken> {
   private tokens: T[]
-  private handlers: {[key: string]: (arg: any) => void} = {}
+  private handlers: Record<string, (arg: any) => void> = {}
   private stopRequested = false
   private parseToken: ParseToken<T>
 

src/parser/parser.ts

@@ -1,19 +1,13 @@
-import { ParseError } from '../util/error'
-import { Liquid, Tokenizer } from '../liquid'
+import { toPromise, assert, isTagToken, isOutputToken, ParseError } from '../util'
+import { Tokenizer } from './tokenizer'
 import { ParseStream } from './parse-stream'
-import { isTagToken, isOutputToken } from '../util/type-guards'
-import { OutputToken } from '../tokens/output-token'
-import { Tag } from '../template/tag/tag'
-import { Output } from '../template/output'
-import { HTML } from '../template/html'
-import { Template } from '../template/template'
-import { TopLevelToken } from '../tokens/toplevel-token'
-import { LiquidCache } from '../cache/cache'
-import { Loader, LookupType } from '../fs/loader'
-import { toPromise } from '../util/async'
-import { FS } from '../fs/fs'
+import { TopLevelToken, OutputToken } from '../tokens'
+import { Template, Output, HTML } from '../template'
+import { LiquidCache } from '../cache'
+import { FS, Loader, LookupType } from '../fs'
+import type { Liquid } from '../liquid'
 
-export default class Parser {
+export class Parser {
   public parseFile: (file: string, sync?: boolean, type?: LookupType, currentFile?: string) => Generator<unknown, Template[], Template[] | string>
 
   private liquid: Liquid
@@ -44,7 +38,9 @@ export default class Parser {
   public parseToken (token: TopLevelToken, remainTokens: TopLevelToken[]) {
     try {
       if (isTagToken(token)) {
-        return new Tag(token, remainTokens, this.liquid)
+        const TagClass = this.liquid.tags[token.name]
+        assert(TagClass, `tag "${token.name}" not found`)
+        return new TagClass(token, remainTokens, this.liquid)
       }
       if (isOutputToken(token)) {
         return new Output(token as OutputToken, this.liquid)

src/parser/tokenizer.ts

@@ -1,31 +1,10 @@
-import { whiteSpaceCtrl } from './whitespace-ctrl'
-import { NumberToken } from '../tokens/number-token'
-import { IdentifierToken } from '../tokens/identifier-token'
-import { literalValues } from '../util/literal'
-import { LiteralToken } from '../tokens/literal-token'
-import { OperatorToken } from '../tokens/operator-token'
-import { PropertyAccessToken } from '../tokens/property-access-token'
-import { assert } from '../util/assert'
-import { TopLevelToken } from '../tokens/toplevel-token'
-import { FilterArg } from './filter-arg'
-import { FilterToken } from '../tokens/filter-token'
-import { HashToken } from '../tokens/hash-token'
-import { QuotedToken } from '../tokens/quoted-token'
-import { ellipsis } from '../util/underscore'
-import { HTMLToken } from '../tokens/html-token'
-import { TagToken } from '../tokens/tag-token'
-import { Token } from '../tokens/token'
-import { RangeToken } from '../tokens/range-token'
-import { ValueToken } from '../tokens/value-token'
-import { OutputToken } from '../tokens/output-token'
-import { TokenizationError } from '../util/error'
+import { TagToken, HTMLToken, HashToken, QuotedToken, LiquidTagToken, OutputToken, ValueToken, Token, RangeToken, FilterToken, TopLevelToken, PropertyAccessToken, OperatorToken, LiteralToken, IdentifierToken, NumberToken } from '../tokens'
+import { Trie, createTrie, ellipsis, literalValues, assert, TokenizationError, TYPES, QUOTE, BLANK, IDENTIFIER } from '../util'
+import { Operators, Expression } from '../render'
 import { NormalizedFullOptions, defaultOptions } from '../liquid-options'
-import { TYPES, QUOTE, BLANK, IDENTIFIER } from '../util/character'
+import { FilterArg } from './filter-arg'
 import { matchOperator } from './match-operator'
-import { Trie, createTrie } from '../util/operator-trie'
-import { Expression } from '../render/expression'
-import { Operators } from '../render/operator'
-import { LiquidTagToken } from '../tokens/liquid-tag-token'
+import { whiteSpaceCtrl } from './whitespace-ctrl'
 
 export class Tokenizer {
   p = 0
@@ -36,7 +15,7 @@ export class Tokenizer {
   constructor (
     public input: string,
     operators: Operators = defaultOptions.operators,
-    public file: string = ''
+    public file?: string
   ) {
     this.N = input.length
     this.opTrie = createTrie(operators)

src/parser/whitespace-ctrl.ts

@@ -1,7 +1,6 @@
-import { Token } from '../tokens/token'
-import { isTagToken, isHTMLToken, isDelimitedToken } from '../util/type-guards'
+import { Token } from '../tokens'
 import { NormalizedFullOptions } from '../liquid-options'
-import { TYPES, INLINE_BLANK, BLANK } from '../util/character'
+import { isTagToken, isHTMLToken, isDelimitedToken, TYPES, INLINE_BLANK, BLANK } from '../util'
 
 export function whiteSpaceCtrl (tokens: Token[], options: NormalizedFullOptions) {
   let inRaw = false

src/render/expression.ts

@@ -1,19 +1,8 @@
-import { QuotedToken } from '../tokens/quoted-token'
-import { PropertyAccessToken } from '../tokens/property-access-token'
-import { NumberToken } from '../tokens/number-token'
-import { assert } from '../util/assert'
-import { literalValues } from '../util/literal'
-import { LiteralToken } from '../tokens/literal-token'
-import * as TypeGuards from '../util/type-guards'
-import { Token } from '../tokens/token'
-import { OperatorToken } from '../tokens/operator-token'
-import { RangeToken } from '../tokens/range-token'
-import { parseStringLiteral } from '../parser/parse-string-literal'
-import { Context } from '../context/context'
-import { range } from '../util/underscore'
-import { Operators } from '../render/operator'
-import { UndefinedVariableError } from '../util/error'
-import { toValueSync } from '../util/async'
+import { RangeToken, OperatorToken, Token, LiteralToken, NumberToken, PropertyAccessToken, QuotedToken } from '../tokens'
+import { isQuotedToken, isWordToken, isNumberToken, isLiteralToken, isRangeToken, isPropertyAccessToken, UndefinedVariableError, range, isOperatorToken, literalValues, assert } from '../util'
+import { parseStringLiteral } from '../parser'
+import { Context } from '../context'
+import { Operators } from '../render'
 
 export class Expression {
   private postfix: Token[]
@@ -25,7 +14,7 @@ export class Expression {
     assert(ctx, 'unable to evaluate: context not defined')
     const operands: any[] = []
     for (const token of this.postfix) {
-      if (TypeGuards.isOperatorToken(token)) {
+      if (isOperatorToken(token)) {
         const r = operands.pop()
         const l = operands.pop()
         const result = yield evalOperatorToken(ctx.opts.operators, token, l, r, ctx)
@@ -38,20 +27,13 @@ export class Expression {
   }
 }
 
-/**
- * @deprecated use `_evalToken` instead
- */
-export function * evalToken (token: Token | undefined, ctx: Context, lenient = false) {
-  return toValueSync(_evalToken(token, ctx, lenient))
-}
-
 export function * _evalToken (token: Token | undefined, ctx: Context, lenient = false): IterableIterator<unknown> {
-  if (TypeGuards.isPropertyAccessToken(token)) return yield evalPropertyAccessToken(token, ctx, lenient)
-  if (TypeGuards.isRangeToken(token)) return yield evalRangeToken(token, ctx)
-  if (TypeGuards.isLiteralToken(token)) return evalLiteralToken(token)
-  if (TypeGuards.isNumberToken(token)) return evalNumberToken(token)
-  if (TypeGuards.isWordToken(token)) return token.getText()
-  if (TypeGuards.isQuotedToken(token)) return evalQuotedToken(token)
+  if (isPropertyAccessToken(token)) return yield evalPropertyAccessToken(token, ctx, lenient)
+  if (isRangeToken(token)) return yield evalRangeToken(token, ctx)
+  if (isLiteralToken(token)) return evalLiteralToken(token)
+  if (isNumberToken(token)) return evalNumberToken(token)
+  if (isWordToken(token)) return token.getText()
+  if (isQuotedToken(token)) return evalQuotedToken(token)
 }
 
 function * evalPropertyAccessToken (token: PropertyAccessToken, ctx: Context, lenient: boolean): IterableIterator<unknown> {
@@ -94,7 +76,7 @@ function * evalRangeToken (token: RangeToken, ctx: Context) {
 function * toPostfix (tokens: IterableIterator<Token>): IterableIterator<Token> {
   const ops: OperatorToken[] = []
   for (const token of tokens) {
-    if (TypeGuards.isOperatorToken(token)) {
+    if (isOperatorToken(token)) {
       while (ops.length && ops[ops.length - 1].getPrecedence() > token.getPrecedence()) {
         yield ops.pop()!
       }

src/render/index.ts

@@ -0,0 +1,4 @@
+export * from './render'
+export * from './expression'
+export * from './operator'
+export * from './boolean'

src/render/operator.ts

@@ -1,11 +1,10 @@
 import { isComparable } from '../drop/comparable'
-import { Context } from '../context/context'
-import { isFunction, toValue } from '../util/underscore'
+import { Context } from '../context'
+import { isFunction, toValue } from '../util'
 import { isTruthy } from '../render/boolean'
 
-export interface Operators {
-  [key: string]: (lhs: any, rhs: any, ctx: Context) => boolean;
-}
+export type OperatorHandler = (lhs: any, rhs: any, ctx: Context) => boolean;
+export type Operators = Record<string, OperatorHandler>
 
 export const defaultOperators: Operators = {
   '==': (l: any, r: any) => {

src/render/render.ts

@@ -1,11 +1,7 @@
-import { RenderError } from '../util/error'
-import { Context } from '../context/context'
-import { Template } from '../template/template'
-import { Emitter } from '../emitters/emitter'
-import { SimpleEmitter } from '../emitters/simple-emitter'
-import { StreamedEmitter } from '../emitters/streamed-emitter'
-import { toPromise } from '../util/async'
-import { KeepingTypeEmitter } from '../emitters/keeping-type-emitter'
+import { toPromise, RenderError } from '../util'
+import { Context } from '../context'
+import { Template } from '../template'
+import { Emitter, KeepingTypeEmitter, StreamedEmitter, SimpleEmitter } from '../emitters'
 
 export class Render {
   public renderTemplatesToNodeStream (templates: Template[], ctx: Context): NodeJS.ReadableStream {

src/tags/assign.ts

@@ -1,15 +1,18 @@
-import { Value, Tokenizer, assert, TagImplOptions, TagToken, Context } from '../types'
+import { Value, assert, Tokenizer, Liquid, TopLevelToken, TagToken, Context, Tag } from '..'
+export default class extends Tag {
+  private key: string
+  private value: Value
 
-export default {
-  parse: function (token: TagToken) {
-    const tokenizer = new Tokenizer(token.args, this.liquid.options.operators)
+  constructor (token: TagToken, remainTokens: TopLevelToken[], liquid: Liquid) {
+    super(token, remainTokens, liquid)
+    const tokenizer = new Tokenizer(token.args, liquid.options.operators)
     this.key = tokenizer.readIdentifier().content
     tokenizer.skipBlank()
     assert(tokenizer.peek() === '=', () => `illegal token ${token.getText()}`)
     tokenizer.advance()
     this.value = new Value(tokenizer.remaining(), this.liquid)
-  },
-  render: function * (ctx: Context): Generator<unknown, void, unknown> {
+  }
+  * render (ctx: Context): Generator<unknown, void, unknown> {
     ctx.bottom()[this.key] = yield this.value.value(ctx, this.liquid.options.lenientIf)
   }
-} as TagImplOptions
+}

src/tags/block.ts

@@ -1,29 +1,34 @@
-import BlockMode from '../context/block-mode'
-import { BlockDrop } from '../drop/block-drop'
-import { TagToken, TopLevelToken, Template, Context, TagImpl, Emitter } from '../types'
+import { BlockMode } from '../context'
+import { isTagToken } from '../util'
+import { BlockDrop } from '../drop'
+import { Liquid, TagToken, TopLevelToken, Template, Context, Emitter, Tag } from '..'
 
-export default {
-  parse (this: TagImpl, token: TagToken, remainTokens: TopLevelToken[]) {
+export default class extends Tag {
+  private block: string
+  private tpls: Template[] = []
+  constructor (token: TagToken, remainTokens: TopLevelToken[], liquid: Liquid) {
+    super(token, remainTokens, liquid)
     const match = /\w+/.exec(token.args)
     this.block = match ? match[0] : ''
-    this.tpls = [] as Template[]
-    this.liquid.parser.parseStream(remainTokens)
-      .on('tag:endblock', function () { this.stop() })
-      .on('template', (tpl: Template) => this.tpls.push(tpl))
-      .on('end', () => { throw new Error(`tag ${token.getText()} not closed`) })
-      .start()
-  },
+    while (remainTokens.length) {
+      const token = remainTokens.shift()!
+      if (isTagToken(token) && token.name === 'endblock') return
+      const template = liquid.parser.parseToken(token, remainTokens)
+      this.tpls.push(template)
+    }
+    throw new Error(`tag ${token.getText()} not closed`)
+  }
 
-  * render (this: TagImpl, ctx: Context, emitter: Emitter) {
+  * render (ctx: Context, emitter: Emitter) {
     const blockRender = this.getBlockRender(ctx)
     if (ctx.getRegister('blockMode') === BlockMode.STORE) {
       ctx.getRegister('blocks')[this.block] = blockRender
     } else {
       yield blockRender(new BlockDrop(), emitter)
     }
-  },
+  }
 
-  getBlockRender (this: TagImpl, ctx: Context) {
+  private getBlockRender (ctx: Context) {
     const { liquid, tpls } = this
     const renderChild = ctx.getRegister('blocks')[this.block]
     const renderCurrent = function * (superBlock: BlockDrop, emitter: Emitter) {

src/tags/break.ts

@@ -1,7 +1,7 @@
-import { Emitter, Context } from '../types'
+import { Context, Emitter, Tag } from '..'
 
-export default {
-  render: function (ctx: Context, emitter: Emitter) {
+export default class extends Tag {
+  render (ctx: Context, emitter: Emitter) {
     emitter['break'] = true
   }
 }

src/tags/capture.ts

@@ -1,28 +1,29 @@
-import { Tokenizer, assert, Template, Context, TagImplOptions, TagToken, TopLevelToken } from '../types'
-import { evalQuotedToken } from '../render/expression'
+import { Liquid, Tag, Tokenizer, assert, Template, Context, TagToken, TopLevelToken } from '..'
+import { evalQuotedToken } from '../render'
+import { isTagToken } from '../util'
 
-export default {
-  parse: function (tagToken: TagToken, remainTokens: TopLevelToken[]) {
+export default class extends Tag {
+  private variable: string
+  private templates: Template[] = []
+  constructor (tagToken: TagToken, remainTokens: TopLevelToken[], liquid: Liquid) {
+    super(tagToken, remainTokens, liquid)
     const tokenizer = new Tokenizer(tagToken.args, this.liquid.options.operators)
-    this.variable = readVariableName(tokenizer)
+    this.variable = readVariableName(tokenizer)!
     assert(this.variable, () => `${tagToken.args} not valid identifier`)
 
-    this.templates = []
-
-    const stream = this.liquid.parser.parseStream(remainTokens)
-    stream.on('tag:endcapture', () => stream.stop())
-      .on('template', (tpl: Template) => this.templates.push(tpl))
-      .on('end', () => {
-        throw new Error(`tag ${tagToken.getText()} not closed`)
-      })
-    stream.start()
-  },
-  render: function * (ctx: Context): Generator<unknown, void, string> {
+    while (remainTokens.length) {
+      const token = remainTokens.shift()!
+      if (isTagToken(token) && token.name === 'endcapture') return
+      this.templates.push(liquid.parser.parseToken(token, remainTokens))
+    }
+    throw new Error(`tag ${tagToken.getText()} not closed`)
+  }
+  * render (ctx: Context): Generator<unknown, void, string> {
     const r = this.liquid.renderer
     const html = yield r.renderTemplates(this.templates, ctx)
     ctx.bottom()[this.variable] = html
   }
-} as TagImplOptions
+}
 
 function readVariableName (tokenizer: Tokenizer) {
   const word = tokenizer.readIdentifier().content

src/tags/case.ts

@@ -1,10 +1,12 @@
-import { toValue, _evalToken, Value, Emitter, TagToken, TopLevelToken, Context, Template, TagImplOptions, ParseStream } from '../types'
-import { Tokenizer } from '../parser/tokenizer'
+import { ValueToken, Liquid, Tokenizer, toValue, _evalToken, Value, Emitter, TagToken, TopLevelToken, Context, Template, Tag, ParseStream } from '..'
 
-export default {
-  parse: function (tagToken: TagToken, remainTokens: TopLevelToken[]) {
+export default class extends Tag {
+  private cond: Value
+  private cases: { val?: ValueToken, templates: Template[] }[] = []
+  private elseTemplates: Template[] = []
+  constructor (tagToken: TagToken, remainTokens: TopLevelToken[], liquid: Liquid) {
+    super(tagToken, remainTokens, liquid)
     this.cond = new Value(tagToken.args, this.liquid)
-    this.cases = []
     this.elseTemplates = []
 
     let p: Template[] = []
@@ -31,9 +33,9 @@ export default {
       })
 
     stream.start()
-  },
+  }
 
-  render: function * (ctx: Context, emitter: Emitter) {
+  * render (ctx: Context, emitter: Emitter): Generator<unknown, unknown, unknown> {
     const r = this.liquid.renderer
     const cond = toValue(yield this.cond.value(ctx, ctx.opts.lenientIf))
     for (const branch of this.cases) {
@@ -45,4 +47,4 @@ export default {
     }
     yield r.renderTemplates(this.elseTemplates, ctx, emitter)
   }
-} as TagImplOptions
+}

src/tags/comment.ts

@@ -1,17 +1,14 @@
-import { TagToken } from '../tokens/tag-token'
-import { TopLevelToken } from '../tokens/toplevel-token'
-import { TagImplOptions } from '../template/tag/tag-impl-options'
+import { Liquid, TopLevelToken, TagToken, Tag } from '..'
+import { isTagToken } from '../util'
 
-export default {
-  parse: function (tagToken: TagToken, remainTokens: TopLevelToken[]) {
-    const stream = this.liquid.parser.parseStream(remainTokens)
-    stream
-      .on('token', (token: TagToken) => {
-        if (token.name === 'endcomment') stream.stop()
-      })
-      .on('end', () => {
-        throw new Error(`tag ${tagToken.getText()} not closed`)
-      })
-    stream.start()
+export default class extends Tag {
+  constructor (tagToken: TagToken, remainTokens: TopLevelToken[], liquid: Liquid) {
+    super(tagToken, remainTokens, liquid)
+    while (remainTokens.length) {
+      const token = remainTokens.shift()!
+      if (isTagToken(token) && token.name === 'endcomment') return
+    }
+    throw new Error(`tag ${tagToken.getText()} not closed`)
   }
-} as TagImplOptions
+  render () {}
+}

src/tags/continue.ts

@@ -1,7 +1,7 @@
-import { Emitter, Context } from '../types'
+import { Tag, Emitter, Context } from '..'
 
-export default {
-  render: function (ctx: Context, emitter: Emitter) {
+export default class extends Tag {
+  render (ctx: Context, emitter: Emitter) {
     emitter['continue'] = true
   }
 }

src/tags/cycle.ts

@@ -1,15 +1,14 @@
-import { assert } from '../util/assert'
-import { _evalToken, Emitter, TagToken, Context, TagImplOptions } from '../types'
-import { Tokenizer } from '../parser/tokenizer'
+import { Tokenizer, assert, TopLevelToken, Liquid, ValueToken, _evalToken, Emitter, TagToken, Context, Tag } from '..'
 
-export default {
-  parse: function (tagToken: TagToken) {
+export default class extends Tag {
+  private candidates: ValueToken[] = []
+  private group?: ValueToken
+  constructor (tagToken: TagToken, remainTokens: TopLevelToken[], liquid: Liquid) {
+    super(tagToken, remainTokens, liquid)
     const tokenizer = new Tokenizer(tagToken.args, this.liquid.options.operators)
     const group = tokenizer.readValue()
     tokenizer.skipBlank()
 
-    this.candidates = []
-
     if (group) {
       if (tokenizer.peek() === ':') {
         this.group = group
@@ -23,10 +22,10 @@ export default {
       tokenizer.readTo(',')
     }
     assert(this.candidates.length, () => `empty candidates: ${tagToken.getText()}`)
-  },
+  }
 
-  render: function * (ctx: Context, emitter: Emitter) {
-    const group = yield _evalToken(this.group, ctx)
+  * render (ctx: Context, emitter: Emitter): Generator<unknown, unknown, unknown> {
+    const group = (yield _evalToken(this.group, ctx)) as ValueToken
     const fingerprint = `cycle:${group}:` + this.candidates.join(',')
     const groups = ctx.getRegister('cycle')
     let idx = groups[fingerprint]
@@ -38,7 +37,6 @@ export default {
     const candidate = this.candidates[idx]
     idx = (idx + 1) % this.candidates.length
     groups[fingerprint] = idx
-    const html = yield _evalToken(candidate, ctx)
-    emitter.write(html)
+    return yield _evalToken(candidate, ctx)
   }
-} as TagImplOptions
+}

src/tags/decrement.ts

@@ -1,16 +1,18 @@
-import { Tokenizer, Emitter, TagToken, Context, TagImplOptions } from '../types'
-import { isNumber, stringify } from '../util/underscore'
+import { Tag, Liquid, TopLevelToken, Tokenizer, Emitter, TagToken, Context } from '..'
+import { isNumber, stringify } from '../util'
 
-export default {
-  parse: function (token: TagToken) {
+export default class extends Tag {
+  private variable: string
+  constructor (token: TagToken, remainTokens: TopLevelToken[], liquid: Liquid) {
+    super(token, remainTokens, liquid)
     const tokenizer = new Tokenizer(token.args, this.liquid.options.operators)
     this.variable = tokenizer.readIdentifier().content
-  },
-  render: function (context: Context, emitter: Emitter) {
+  }
+  render (context: Context, emitter: Emitter) {
     const scope = context.environments
     if (!isNumber(scope[this.variable])) {
       scope[this.variable] = 0
     }
     emitter.write(stringify(--scope[this.variable]))
   }
-} as TagImplOptions
+}

src/tags/echo.ts

@@ -1,13 +1,13 @@
-import { Value } from '../template/value'
-import { Emitter } from '../emitters/emitter'
-import { TagImplOptions, TagToken, Context } from '../types'
+import { Liquid, TopLevelToken, Emitter, Value, TagToken, Context, Tag } from '..'
 
-export default {
-  parse: function (token: TagToken) {
+export default class extends Tag {
+  private value: Value
+  constructor (token: TagToken, remainTokens: TopLevelToken[], liquid: Liquid) {
+    super(token, remainTokens, liquid)
     this.value = new Value(token.args, this.liquid)
-  },
-  render: function * (ctx: Context, emitter: Emitter): Generator<unknown, void, unknown> {
+  }
+  * render (ctx: Context, emitter: Emitter): Generator<unknown, void, unknown> {
     const val = yield this.value.value(ctx, false)
     emitter.write(val)
   }
-} as TagImplOptions
+}

src/tags/for.ts

@@ -1,24 +1,27 @@
-import { assert, Tokenizer, _evalToken, Emitter, TagToken, TopLevelToken, Context, Template, TagImplOptions, ParseStream } from '../types'
+import { Hash, ValueToken, Liquid, Tag, Tokenizer, _evalToken, Emitter, TagToken, TopLevelToken, Context, Template, ParseStream } from '..'
 import { toEnumerable } from '../util/collection'
 import { ForloopDrop } from '../drop/forloop-drop'
-import { Hash, HashValue } from '../template/tag/hash'
 
 const MODIFIERS = ['offset', 'limit', 'reversed']
 
 type valueof<T> = T[keyof T]
 
-export default {
-  type: 'block',
-  parse: function (token: TagToken, remainTokens: TopLevelToken[]) {
-    const tokenizer = new Tokenizer(token.args, this.liquid.options.operators)
+export default class extends Tag {
+  private variable: string
+  private collection: ValueToken
+  private hash: Hash
+  private templates: Template[]
+  private elseTemplates: Template[]
 
+  constructor (token: TagToken, remainTokens: TopLevelToken[], liquid: Liquid) {
+    super(token, remainTokens, liquid)
+    const tokenizer = new Tokenizer(token.args, this.liquid.options.operators)
     const variable = tokenizer.readIdentifier()
     const inStr = tokenizer.readIdentifier()
     const collection = tokenizer.readValue()
-    assert(
-      variable.size() && inStr.content === 'in' && collection,
-      () => `illegal tag: ${token.getText()}`
-    )
+    if (!variable.size() || inStr.content !== 'in' || !collection) {
+      throw new Error(`illegal tag: ${token.getText()}`)
+    }
 
     this.variable = variable.content
     this.collection = collection
@@ -37,8 +40,8 @@ export default {
       })
 
     stream.start()
-  },
-  render: function * (ctx: Context, emitter: Emitter): Generator<unknown, void | string, HashValue | Template[]> {
+  }
+  * render (ctx: Context, emitter: Emitter): Generator<unknown, void | string, Template[]> {
     const r = this.liquid.renderer
     let collection = toEnumerable(yield _evalToken(this.collection, ctx))
 
@@ -77,7 +80,7 @@ export default {
     }
     ctx.pop()
   }
-} as TagImplOptions
+}
 
 function reversed<T> (arr: Array<T>) {
   return [...arr].reverse()

src/tags/if.ts

@@ -1,12 +1,13 @@
-import { Value, Emitter, isTruthy, TagToken, TopLevelToken, Context, Template, TagImplOptions } from '../types'
+import { Liquid, Tag, Value, Emitter, isTruthy, TagToken, TopLevelToken, Context, Template } from '..'
 
-export default {
-  parse: function (tagToken: TagToken, remainTokens: TopLevelToken[]) {
-    this.branches = []
-    this.elseTemplates = []
+export default class extends Tag {
+  private branches: { predicate: Value, templates: Template[] }[] = []
+  private elseTemplates: Template[] = []
 
+  constructor (tagToken: TagToken, remainTokens: TopLevelToken[], liquid: Liquid) {
+    super(tagToken, remainTokens, liquid)
     let p
-    this.liquid.parser.parseStream(remainTokens)
+    liquid.parser.parseStream(remainTokens)
       .on('start', () => this.branches.push({
         predicate: new Value(tagToken.args, this.liquid),
         templates: (p = [])
@@ -20,9 +21,9 @@ export default {
       .on('template', (tpl: Template) => p.push(tpl))
       .on('end', () => { throw new Error(`tag ${tagToken.getText()} not closed`) })
       .start()
-  },
+  }
 
-  render: function * (ctx: Context, emitter: Emitter): Generator<unknown, void, string> {
+  * render (ctx: Context, emitter: Emitter): Generator<unknown, void, string> {
     const r = this.liquid.renderer
 
     for (const { predicate, templates } of this.branches) {
@@ -34,4 +35,4 @@ export default {
     }
     yield r.renderTemplates(this.elseTemplates, ctx, emitter)
   }
-} as TagImplOptions
+}

src/tags/include.ts

@@ -1,14 +1,15 @@
-import { assert, Tokenizer, _evalToken, Hash, Emitter, TagToken, Context, TagImplOptions } from '../types'
-import BlockMode from '../context/block-mode'
+import { Template, ValueToken, TopLevelToken, Liquid, Tag, assert, Tokenizer, _evalToken, Hash, Emitter, TagToken, Context } from '..'
+import { BlockMode, Scope } from '../context'
 import { parseFilePath, renderFilePath } from './render'
 
-export default {
-  parseFilePath,
-  renderFilePath,
-  parse: function (token: TagToken) {
+export default class extends Tag {
+  private withVar?: ValueToken
+  private hash: Hash
+  constructor (token: TagToken, remainTokens: TopLevelToken[], liquid: Liquid) {
+    super(token, remainTokens, liquid)
     const args = token.args
     const tokenizer = new Tokenizer(args, this.liquid.options.operators)
-    this['file'] = this.parseFilePath(tokenizer, this.liquid)
+    this['file'] = parseFilePath(tokenizer, this.liquid)
     this['currentFile'] = token.file
 
     const begin = tokenizer.p
@@ -21,22 +22,22 @@ export default {
     } else tokenizer.p = begin
 
     this.hash = new Hash(tokenizer.remaining(), this.liquid.options.jekyllInclude)
-  },
-  render: function * (ctx: Context, emitter: Emitter) {
+  }
+  * render (ctx: Context, emitter: Emitter): Generator<unknown, void, unknown> {
     const { liquid, hash, withVar } = this
     const { renderer } = liquid
-    const filepath = yield this.renderFilePath(this['file'], ctx, liquid)
+    const filepath = (yield renderFilePath(this['file'], ctx, liquid)) as string
     assert(filepath, () => `illegal filename "${filepath}"`)
 
     const saved = ctx.saveRegister('blocks', 'blockMode')
     ctx.setRegister('blocks', {})
     ctx.setRegister('blockMode', BlockMode.OUTPUT)
-    const scope = yield hash.render(ctx)
+    const scope = (yield hash.render(ctx)) as Scope
     if (withVar) scope[filepath] = yield _evalToken(withVar, ctx)
-    const templates = yield liquid._parsePartialFile(filepath, ctx.sync, this['currentFile'])
+    const templates = (yield liquid._parsePartialFile(filepath, ctx.sync, this['currentFile'])) as Template[]
     ctx.push(ctx.opts.jekyllInclude ? { include: scope } : scope)
     yield renderer.renderTemplates(templates, ctx, emitter)
     ctx.pop()
     ctx.restoreRegister(saved)
   }
-} as TagImplOptions
+}

src/tags/increment.ts

@@ -1,12 +1,14 @@
-import { isNumber, stringify } from '../util/underscore'
-import { Tokenizer, Emitter, TagToken, Context, TagImplOptions } from '../types'
+import { isNumber, stringify } from '../util'
+import { Tag, Liquid, TopLevelToken, Tokenizer, Emitter, TagToken, Context } from '..'
 
-export default {
-  parse: function (token: TagToken) {
+export default class extends Tag {
+  private variable: string
+  constructor (token: TagToken, remainTokens: TopLevelToken[], liquid: Liquid) {
+    super(token, remainTokens, liquid)
     const tokenizer = new Tokenizer(token.args, this.liquid.options.operators)
     this.variable = tokenizer.readIdentifier().content
-  },
-  render: function (context: Context, emitter: Emitter) {
+  }
+  render (context: Context, emitter: Emitter) {
     const scope = context.environments
     if (!isNumber(scope[this.variable])) {
       scope[this.variable] = 0
@@ -15,4 +17,4 @@ export default {
     scope[this.variable]++
     emitter.write(stringify(val))
   }
-} as TagImplOptions
+}

src/tags/index.ts

@@ -19,8 +19,8 @@ import Continue from './continue'
 import echo from './echo'
 import liquid from './liquid'
 import inlineComment from './inline-comment'
-import { TagImplOptions } from '../template/tag/tag-impl-options'
+import type { TagClass } from '../template/tag'
 
-export const tags: { [key: string]: TagImplOptions } = {
+export const tags: Record<string, TagClass> = {
   assign, 'for': For, capture, 'case': Case, comment, include, render, decrement, increment, cycle, 'if': If, layout, block, raw, tablerow, unless, 'break': Break, 'continue': Continue, echo, liquid, '#': inlineComment
 }

src/tags/inline-comment.ts

@@ -1,11 +1,11 @@
-import { TagToken } from '../tokens/tag-token'
-import { TopLevelToken } from '../tokens/toplevel-token'
-import { TagImplOptions } from '../template/tag/tag-impl-options'
+import { TagToken, Liquid, TopLevelToken, Tag } from '..'
 
-export default {
-  parse: function (tagToken: TagToken, remainTokens: TopLevelToken[]) {
+export default class extends Tag {
+  constructor (tagToken: TagToken, remainTokens: TopLevelToken[], liquid: Liquid) {
+    super(tagToken, remainTokens, liquid)
     if (tagToken.args.search(/\n\s*[^#\s]/g) !== -1) {
       throw new Error('every line of an inline comment must start with a \'#\' character')
     }
   }
-} as TagImplOptions
+  render () { }
+}

src/tags/layout.ts

@@ -1,29 +1,31 @@
-import { assert, Tokenizer, Emitter, Hash, TagToken, TopLevelToken, Context, TagImplOptions } from '../types'
-import BlockMode from '../context/block-mode'
-import { parseFilePath, renderFilePath } from './render'
-import { BlankDrop } from '../drop/blank-drop'
+import { Scope, Template, Liquid, Tag, assert, Tokenizer, Emitter, Hash, TagToken, TopLevelToken, Context } from '..'
+import { BlockMode } from '../context'
+import { parseFilePath, renderFilePath, ParsedFileName } from './render'
+import { BlankDrop } from '../drop'
 
-export default {
-  parseFilePath,
-  renderFilePath,
-  parse: function (token: TagToken, remainTokens: TopLevelToken[]) {
+export default class extends Tag {
+  private hash: Hash
+  private tpls: Template[]
+  private file?: ParsedFileName
+  constructor (token: TagToken, remainTokens: TopLevelToken[], liquid: Liquid) {
+    super(token, remainTokens, liquid)
     const tokenizer = new Tokenizer(token.args, this.liquid.options.operators)
-    this['file'] = this.parseFilePath(tokenizer, this.liquid)
+    this.file = parseFilePath(tokenizer, this.liquid)
     this['currentFile'] = token.file
     this.hash = new Hash(tokenizer.remaining())
     this.tpls = this.liquid.parser.parseTokens(remainTokens)
-  },
-  render: function * (ctx: Context, emitter: Emitter) {
+  }
+  * render (ctx: Context, emitter: Emitter): Generator<unknown, unknown, unknown> {
     const { liquid, hash, file } = this
     const { renderer } = liquid
-    if (file === null) {
+    if (file === undefined) {
       ctx.setRegister('blockMode', BlockMode.OUTPUT)
       yield renderer.renderTemplates(this.tpls, ctx, emitter)
       return
     }
-    const filepath = yield this.renderFilePath(this['file'], ctx, liquid)
+    const filepath = (yield renderFilePath(this.file, ctx, liquid)) as string
     assert(filepath, () => `illegal filename "${filepath}"`)
-    const templates = yield liquid._parseLayoutFile(filepath, ctx.sync, this['currentFile'])
+    const templates = (yield liquid._parseLayoutFile(filepath, ctx.sync, this['currentFile'])) as Template[]
 
     // render remaining contents and store rendered results
     ctx.setRegister('blockMode', BlockMode.STORE)
@@ -35,8 +37,8 @@ export default {
     ctx.setRegister('blockMode', BlockMode.OUTPUT)
 
     // render the layout file use stored blocks
-    ctx.push(yield hash.render(ctx))
+    ctx.push((yield hash.render(ctx)) as Scope)
     yield renderer.renderTemplates(templates, ctx, emitter)
     ctx.pop()
   }
-} as TagImplOptions
+}

src/tags/liquid.ts

@@ -1,14 +1,14 @@
-import { Emitter } from '../emitters/emitter'
-import { TagImplOptions, TagToken, Context } from '../types'
-import { Tokenizer } from '../parser/tokenizer'
+import { Template, Tokenizer, Emitter, Liquid, TopLevelToken, TagToken, Context, Tag } from '..'
 
-export default {
-  parse: function (token: TagToken) {
+export default class extends Tag {
+  private tpls: Template[]
+  constructor (token: TagToken, remainTokens: TopLevelToken[], liquid: Liquid) {
+    super(token, remainTokens, liquid)
     const tokenizer = new Tokenizer(token.args, this.liquid.options.operators)
     const tokens = tokenizer.readLiquidTagTokens(this.liquid.options)
     this.tpls = this.liquid.parser.parseTokens(tokens)
-  },
-  render: function * (ctx: Context, emitter: Emitter): Generator<unknown, void, unknown> {
+  }
+  * render (ctx: Context, emitter: Emitter): Generator<unknown, void, unknown> {
     yield this.liquid.renderer.renderTemplates(this.tpls, ctx, emitter)
   }
-} as TagImplOptions
+}

src/tags/raw.ts

@@ -1,21 +1,18 @@
-import { TagToken, TopLevelToken, TagImplOptions } from '../types'
+import { Liquid, TagToken, TopLevelToken, Tag } from '..'
+import { isTagToken } from '../util'
 
-export default {
-  parse: function (tagToken: TagToken, remainTokens: TopLevelToken[]) {
-    this.tokens = []
-
-    const stream = this.liquid.parser.parseStream(remainTokens)
-    stream
-      .on('token', (token: TagToken) => {
-        if (token.name === 'endraw') stream.stop()
-        else this.tokens.push(token)
-      })
-      .on('end', () => {
-        throw new Error(`tag ${tagToken.getText()} not closed`)
-      })
-    stream.start()
-  },
-  render: function () {
+export default class extends Tag {
+  private tokens: TopLevelToken[] = []
+  constructor (tagToken: TagToken, remainTokens: TopLevelToken[], liquid: Liquid) {
+    super(tagToken, remainTokens, liquid)
+    while (remainTokens.length) {
+      const token = remainTokens.shift()!
+      if (isTagToken(token) && token.name === 'endraw') return
+      this.tokens.push(token)
+    }
+    throw new Error(`tag ${tagToken.getText()} not closed`)
+  }
+  render () {
     return this.tokens.map((token: TopLevelToken) => token.getText()).join('')
   }
-} as TagImplOptions
+}

src/tags/render.ts

@@ -1,18 +1,20 @@
 import { __assign } from 'tslib'
-import { assert } from '../util/assert'
-import { ForloopDrop } from '../drop/forloop-drop'
-import { toEnumerable } from '../util/collection'
-import { Liquid } from '../liquid'
-import { Token, Template, evalQuotedToken, TypeGuards, Tokenizer, _evalToken, Hash, Emitter, TagToken, Context, TagImplOptions } from '../types'
+import { ForloopDrop } from '../drop'
+import { toEnumerable } from '../util'
+import { TopLevelToken, assert, Liquid, Token, Template, evalQuotedToken, TypeGuards, Tokenizer, _evalToken, Hash, Emitter, TagToken, Context, Tag } from '..'
 
-export default {
-  parseFilePath,
-  renderFilePath,
-  parse: function (token: TagToken) {
+export type ParsedFileName = Template[] | Token | string | undefined
+
+export default class extends Tag {
+  private file: ParsedFileName
+  private currentFile?: string
+  private hash: Hash
+  constructor (token: TagToken, remainTokens: TopLevelToken[], liquid: Liquid) {
+    super(token, remainTokens, liquid)
     const args = token.args
     const tokenizer = new Tokenizer(args, this.liquid.options.operators)
-    this['file'] = this.parseFilePath(tokenizer, this.liquid)
-    this['currentFile'] = token.file
+    this.file = parseFilePath(tokenizer, this.liquid)
+    this.currentFile = token.file
     while (!tokenizer.end()) {
       tokenizer.skipBlank()
       const begin = tokenizer.p
@@ -33,8 +35,7 @@ export default {
             this[keyword.content] = { value, alias: alias && alias.content }
             tokenizer.skipBlank()
             if (tokenizer.peek() === ',') tokenizer.advance()
-            // matched!
-            continue
+            continue // matched!
           }
         }
       }
@@ -45,10 +46,10 @@ export default {
       break
     }
     this.hash = new Hash(tokenizer.remaining())
-  },
-  render: function * (ctx: Context, emitter: Emitter) {
+  }
+  * render (ctx: Context, emitter: Emitter): Generator<unknown, void, unknown> {
     const { liquid, hash } = this
-    const filepath = yield this.renderFilePath(this['file'], ctx, liquid)
+    const filepath = (yield renderFilePath(this['file'], ctx, liquid)) as string
     assert(filepath, () => `illegal filename "${filepath}"`)
 
     const childCtx = new Context({}, ctx.opts, { sync: ctx.sync, globals: ctx.globals, strictVariables: ctx.strictVariables })
@@ -61,23 +62,20 @@ export default {
 
     if (this['for']) {
       const { value, alias } = this['for']
-      let collection = yield _evalToken(value, ctx)
-      collection = toEnumerable(collection)
+      const collection = toEnumerable(yield _evalToken(value, ctx))
       scope['forloop'] = new ForloopDrop(collection.length, value.getText(), alias)
       for (const item of collection) {
         scope[alias] = item
-        const templates = yield liquid._parsePartialFile(filepath, childCtx.sync, this['currentFile'])
+        const templates = (yield liquid._parsePartialFile(filepath, childCtx.sync, this['currentFile'])) as Template[]
         yield liquid.renderer.renderTemplates(templates, childCtx, emitter)
         scope['forloop'].next()
       }
     } else {
-      const templates = yield liquid._parsePartialFile(filepath, childCtx.sync, this['currentFile'])
+      const templates = (yield liquid._parsePartialFile(filepath, childCtx.sync, this['currentFile'])) as Template[]
       yield liquid.renderer.renderTemplates(templates, childCtx, emitter)
     }
   }
-} as TagImplOptions
-
-type ParsedFileName = Template[] | Token | string | undefined
+}
 
 /**
  * @return null for "none",
@@ -85,11 +83,11 @@ type ParsedFileName = Template[] | Token | string | undefined
  * @return Token for expression (not quoted)
  * @throws TypeError if cannot read next token
  */
-export function parseFilePath (tokenizer: Tokenizer, liquid: Liquid): ParsedFileName | null {
+export function parseFilePath (tokenizer: Tokenizer, liquid: Liquid): ParsedFileName {
   if (liquid.options.dynamicPartials) {
     const file = tokenizer.readValue()
     if (file === undefined) throw new TypeError(`illegal argument "${tokenizer.input}"`)
-    if (file.getText() === 'none') return null
+    if (file.getText() === 'none') return
     if (TypeGuards.isQuotedToken(file)) {
       // for filenames like "files/{{file}}", eval as liquid template
       const templates = liquid.parse(evalQuotedToken(file))
@@ -99,7 +97,7 @@ export function parseFilePath (tokenizer: Tokenizer, liquid: Liquid): ParsedFile
   }
   const tokens = [...tokenizer.readFileNameTemplate(liquid.options)]
   const templates = optimize(liquid.parser.parseTokens(tokens))
-  return templates === 'none' ? null : templates
+  return templates === 'none' ? undefined : templates
 }
 
 function optimize (templates: Template[]): string | Template[] {

src/tags/tablerow.ts

@@ -1,20 +1,28 @@
 import { toEnumerable } from '../util/collection'
-import { assert, _evalToken, Emitter, Hash, TagToken, TopLevelToken, Context, Template, TagImplOptions, ParseStream } from '../types'
+import { ValueToken, Liquid, Tag, _evalToken, Emitter, Hash, TagToken, TopLevelToken, Context, Template, ParseStream } from '..'
 import { TablerowloopDrop } from '../drop/tablerowloop-drop'
 import { Tokenizer } from '../parser/tokenizer'
 
-export default {
-  parse: function (tagToken: TagToken, remainTokens: TopLevelToken[]) {
+export default class extends Tag {
+  private variable: string
+  private hash: Hash
+  private templates: Template[]
+  private collection: ValueToken
+  constructor (tagToken: TagToken, remainTokens: TopLevelToken[], liquid: Liquid) {
+    super(tagToken, remainTokens, liquid)
     const tokenizer = new Tokenizer(tagToken.args, this.liquid.options.operators)
 
     const variable = tokenizer.readIdentifier()
     tokenizer.skipBlank()
 
-    const tmp = tokenizer.readIdentifier()
-    assert(tmp && tmp.content === 'in', () => `illegal tag: ${tagToken.getText()}`)
+    const predicate = tokenizer.readIdentifier()
+    const collectionToken = tokenizer.readValue()
+    if (predicate.content !== 'in' || !collectionToken) {
+      throw new Error(`illegal tag: ${tagToken.getText()}`)
+    }
 
     this.variable = variable.content
-    this.collection = tokenizer.readValue()
+    this.collection = collectionToken
     this.hash = new Hash(tokenizer.remaining())
     this.templates = []
 
@@ -28,11 +36,11 @@ export default {
       })
 
     stream.start()
-  },
+  }
 
-  render: function * (ctx: Context, emitter: Emitter) {
+  * render (ctx: Context, emitter: Emitter): Generator<unknown, void, unknown> {
     let collection = toEnumerable(yield _evalToken(this.collection, ctx))
-    const hash = yield this.hash.render(ctx)
+    const hash = (yield this.hash.render(ctx)) as Record<string, any>
     const offset = hash.offset || 0
     const limit = (hash.limit === undefined) ? collection.length : hash.limit
 
@@ -57,4 +65,4 @@ export default {
     if (collection.length) emitter.write('</tr>')
     ctx.pop()
   }
-} as TagImplOptions
+}

src/tags/unless.ts

@@ -1,9 +1,10 @@
-import { Value, TopLevelToken, Template, Emitter, isTruthy, isFalsy, Context, TagImplOptions, TagToken } from '../types'
+import { Liquid, Tag, Value, TopLevelToken, Template, Emitter, isTruthy, isFalsy, Context, TagToken } from '..'
 
-export default {
-  parse: function (tagToken: TagToken, remainTokens: TopLevelToken[]) {
-    this.branches = []
-    this.elseTemplates = []
+export default class extends Tag {
+  private branches: { predicate: Value, test: (val: any, ctx: Context) => boolean, templates: Template[] }[] = []
+  private elseTemplates: Template[] = []
+  constructor (tagToken: TagToken, remainTokens: TopLevelToken[], liquid: Liquid) {
+    super(tagToken, remainTokens, liquid)
     let p
     this.liquid.parser.parseStream(remainTokens)
       .on('start', () => this.branches.push({
@@ -21,9 +22,9 @@ export default {
       .on('template', (tpl: Template) => p.push(tpl))
       .on('end', () => { throw new Error(`tag ${tagToken.getText()} not closed`) })
       .start()
-  },
+  }
 
-  render: function * (ctx: Context, emitter: Emitter) {
+  * render (ctx: Context, emitter: Emitter): Generator<unknown, unknown, unknown> {
     const r = this.liquid.renderer
 
     for (const { predicate, test, templates } of this.branches) {
@@ -36,4 +37,4 @@ export default {
 
     yield r.renderTemplates(this.elseTemplates, ctx, emitter)
   }
-} as TagImplOptions
+}

src/template/filter-impl-options.ts

@@ -0,0 +1,11 @@
+import type { Context } from '../context'
+import type { Liquid } from '../liquid'
+
+export interface FilterImpl {
+  context: Context;
+  liquid: Liquid;
+}
+
+export interface FilterImplOptions {
+  (this: FilterImpl, value: any, ...args: any[]): any;
+}

src/template/filter.ts

@@ -1,9 +1,9 @@
-import { _evalToken } from '../../render/expression'
-import { Context } from '../../context/context'
-import { identify } from '../../util/underscore'
+import { _evalToken } from '../render'
+import { Context } from '../context'
+import { identify } from '../util/underscore'
 import { FilterImplOptions } from './filter-impl-options'
-import { FilterArg, isKeyValuePair } from '../../parser/filter-arg'
-import { Liquid } from '../../liquid'
+import { FilterArg, isKeyValuePair } from '../parser/filter-arg'
+import { Liquid } from '../liquid'
 
 export class Filter {
   public name: string
@@ -11,7 +11,7 @@ export class Filter {
   private impl: FilterImplOptions
   private liquid: Liquid
 
-  public constructor (name: string, impl: FilterImplOptions, args: FilterArg[], liquid: Liquid) {
+  public constructor (name: string, impl: FilterImplOptions | undefined, args: FilterArg[], liquid: Liquid) {
     this.name = name
     this.impl = impl || identify
     this.args = args

src/template/filter/filter-impl-options.ts

@@ -1,5 +0,0 @@
-import { FilterImpl } from './filter-impl'
-
-export interface FilterImplOptions {
-  (this: FilterImpl, value: any, ...args: any[]): any;
-}

src/template/filter/filter-impl.ts

@@ -1,7 +0,0 @@
-import { Context } from '../../context/context'
-import { Liquid } from '../../liquid'
-
-export interface FilterImpl {
-  context: Context;
-  liquid: Liquid;
-}

src/template/filter/filter-map.ts

@@ -1,28 +0,0 @@
-import { FilterImplOptions } from './filter-impl-options'
-import { Filter } from './filter'
-import { FilterArg } from '../../parser/filter-arg'
-import { assert } from '../../util/assert'
-import { Liquid } from '../../liquid'
-
-export class FilterMap {
-  private impls: {[key: string]: FilterImplOptions} = {}
-
-  constructor (
-    private readonly strictFilters: boolean,
-    private readonly liquid: Liquid
-  ) {}
-
-  get (name: string) {
-    const impl = this.impls[name]
-    assert(impl || !this.strictFilters, () => `undefined filter: ${name}`)
-    return impl
-  }
-
-  set (name: string, impl: FilterImplOptions) {
-    this.impls[name] = impl
-  }
-
-  create (name: string, args: FilterArg[]) {
-    return new Filter(name, this.get(name), args, this.liquid)
-  }
-}

src/template/hash.ts

@@ -1,10 +1,9 @@
-import { _evalToken } from '../../render/expression'
-import { Context } from '../../context/context'
-import { Tokenizer } from '../../parser/tokenizer'
+import { _evalToken } from '../render/expression'
+import { Context } from '../context/context'
+import { Tokenizer } from '../parser/tokenizer'
+import { Token } from '../tokens/token'
 
-export interface HashValue {
-  [key: string]: any;
-}
+type HashValueTokens = Record<string, Token | undefined>
 
 /**
  * Key-Value Pairs Representing Tag Arguments
@@ -15,14 +14,14 @@ export interface HashValue {
  *    hash['reversed'] === undefined
  */
 export class Hash {
-  hash: HashValue = {}
+  hash: HashValueTokens = {}
   constructor (markup: string, jekyllStyle?: boolean) {
     const tokenizer = new Tokenizer(markup, {})
     for (const hash of tokenizer.readHashes(jekyllStyle)) {
       this.hash[hash.name.content] = hash.value
     }
   }
-  * render (ctx: Context): Generator<unknown, HashValue, unknown> {
+  * render (ctx: Context): Generator<unknown, Record<string, any>, unknown> {
     const hash = {}
     for (const key of Object.keys(this.hash)) {
       hash[key] = this.hash[key] === undefined ? true : yield _evalToken(this.hash[key], ctx)

src/template/html.ts

@@ -1,8 +1,7 @@
-import { TemplateImpl } from '../template/template-impl'
-import { Template } from '../template/template'
-import { HTMLToken } from '../tokens/html-token'
-import { Context } from '../context/context'
-import { Emitter } from '../emitters/emitter'
+import { TemplateImpl, Template } from '../template'
+import { HTMLToken } from '../tokens'
+import { Context } from '../context'
+import { Emitter } from '../emitters'
 
 export class HTML extends TemplateImpl<HTMLToken> implements Template {
   private str: string

src/template/index.ts

@@ -0,0 +1,10 @@
+export * from './template'
+export * from './template-impl'
+export * from './tag'
+export * from './tag-options-adapter'
+export * from './filter'
+export * from './filter-impl-options'
+export * from './hash'
+export * from './value'
+export * from './output'
+export * from './html'

src/template/output.ts

@@ -1,11 +1,10 @@
 import { Value } from './value'
-import { TemplateImpl } from '../template/template-impl'
-import { Template } from '../template/template'
+import { Template, TemplateImpl } from '../template'
 import { Context } from '../context/context'
 import { Emitter } from '../emitters/emitter'
 import { OutputToken } from '../tokens/output-token'
 import { Liquid } from '../liquid'
-import { Filter } from './filter/filter'
+import { Filter } from './filter'
 
 export class Output extends TemplateImpl<OutputToken> implements Template {
   private value: Value

src/template/tag-options-adapter.ts

@@ -0,0 +1,27 @@
+import { isFunction } from '../util'
+import { Hash } from './hash'
+import { Tag, TagClass, TagRenderReturn } from './tag'
+import { TagToken, TopLevelToken } from '../tokens'
+import { Emitter } from '../emitters'
+import { Context } from '../context'
+import type { Liquid } from '../liquid'
+
+export interface TagImplOptions {
+  parse?: (this: Tag, token: TagToken, remainingTokens: TopLevelToken[]) => void;
+  render: (this: Tag, ctx: Context, emitter: Emitter, hash: Record<string, any>) => TagRenderReturn;
+}
+
+export function createTagClass (options: TagImplOptions): TagClass {
+  return class extends Tag {
+    constructor (token: TagToken, tokens: TopLevelToken[], liquid: Liquid) {
+      super(token, tokens, liquid)
+      if (isFunction(options.parse)) {
+        options.parse.call(this, token, tokens)
+      }
+    }
+    * render (ctx: Context, emitter: Emitter): TagRenderReturn {
+      const hash = (yield new Hash(this.token.args).render(ctx)) as Record<string, any>
+      return yield options.render.call(this, ctx, emitter, hash)
+    }
+  }
+}

src/template/tag.ts

@@ -0,0 +1,24 @@
+import { TemplateImpl } from './template-impl'
+import type { Emitter } from '../emitters/emitter'
+import type { Context } from '../context/context'
+import type { TopLevelToken, TagToken } from '../tokens'
+import type { Template } from './template'
+import type { Liquid } from '../liquid'
+
+export type TagRenderReturn = Generator<unknown, unknown, unknown> | Promise<unknown> | unknown
+
+export abstract class Tag extends TemplateImpl<TagToken> implements Template {
+  public name: string
+  protected liquid: Liquid
+
+  public constructor (token: TagToken, remainTokens: TopLevelToken[], liquid: Liquid) {
+    super(token)
+    this.name = token.name
+    this.liquid = liquid
+  }
+  public abstract render (ctx: Context, emitter: Emitter): TagRenderReturn;
+}
+
+export interface TagClass {
+  new(token: TagToken, tokens: TopLevelToken[], liquid: Liquid): Tag
+}

src/template/tag/tag-impl-options.ts

@@ -1,11 +0,0 @@
-import { Context } from '../../context/context'
-import { TagToken } from '../../tokens/tag-token'
-import { TopLevelToken } from '../../tokens/toplevel-token'
-import { TagImpl } from './tag-impl'
-import { HashValue } from '../../template/tag/hash'
-import { Emitter } from '../../emitters/emitter'
-
-export interface TagImplOptions {
-  parse?: (this: TagImpl, token: TagToken, remainingTokens: TopLevelToken[]) => void;
-  render: (this: TagImpl, ctx: Context, emitter: Emitter, hash: HashValue) => void | string | Promise<void | string> | Generator<unknown, void | string, unknown>;
-}

src/template/tag/tag-impl.ts

@@ -1,7 +0,0 @@
-import { Liquid } from '../../liquid'
-import { TagImplOptions } from './tag-impl-options'
-
-export interface TagImpl extends TagImplOptions {
-  liquid: Liquid;
-  [key: string]: any;
-}

src/template/tag/tag-map.ts

@@ -1,16 +0,0 @@
-import { TagImplOptions } from './tag-impl-options'
-import { assert } from '../../util/assert'
-
-export class TagMap {
-  private impls: {[key: string]: TagImplOptions} = {}
-
-  get (name: string) {
-    const impl = this.impls[name]
-    assert(impl, () => `tag "${name}" not found`)
-    return impl
-  }
-
-  set (name: string, impl: TagImplOptions) {
-    this.impls[name] = impl
-  }
-}

src/template/tag/tag.ts

@@ -1,29 +0,0 @@
-import { isFunction } from '../../util/underscore'
-import { Liquid } from '../../liquid'
-import { TemplateImpl } from '../../template/template-impl'
-import { Emitter, Hash, Context, TagToken, Template, TopLevelToken } from '../../types'
-import { TagImpl } from './tag-impl'
-import { HashValue } from './hash'
-
-export class Tag extends TemplateImpl<TagToken> implements Template {
-  public name: string
-  private impl: TagImpl
-
-  public constructor (token: TagToken, tokens: TopLevelToken[], liquid: Liquid) {
-    super(token)
-    this.name = token.name
-
-    const impl = liquid.tags.get(token.name)
-
-    this.impl = Object.create(impl)
-    this.impl.liquid = liquid
-    if (this.impl.parse) {
-      this.impl.parse(token, tokens)
-    }
-  }
-  public * render (ctx: Context, emitter: Emitter): Generator<unknown, unknown, HashValue | unknown> {
-    const hash = (yield new Hash(this.token.args).render(ctx)) as HashValue
-    const impl = this.impl
-    if (isFunction(impl.render)) return yield impl.render(ctx, emitter, hash)
-  }
-}

src/template/value.ts

@@ -1,8 +1,9 @@
-import { Expression } from '../render/expression'
-import { Tokenizer } from '../parser/tokenizer'
-import { Filter } from './filter/filter'
-import { Context } from '../context/context'
-import { Liquid } from '../liquid'
+import { Filter } from './filter'
+import { Expression } from '../render'
+import { Tokenizer } from '../parser'
+import { assert } from '../util'
+import type { Liquid } from '../liquid'
+import type { Context } from '../context'
 
 export class Value {
   public readonly filters: Filter[] = []
@@ -14,7 +15,7 @@ export class Value {
   public constructor (str: string, liquid: Liquid) {
     const tokenizer = new Tokenizer(str, liquid.options.operators)
     this.initial = tokenizer.readExpression()
-    this.filters = tokenizer.readFilters().map(({ name, args }) => new Filter(name, liquid.filters.get(name), args, liquid))
+    this.filters = tokenizer.readFilters().map(({ name, args }) => new Filter(name, this.getFilter(liquid, name), args, liquid))
   }
   public * value (ctx: Context, lenient: boolean): Generator<unknown, unknown, unknown> {
     lenient = lenient || (ctx.opts.lenientIf && this.filters.length > 0 && this.filters[0].name === 'default')
@@ -25,4 +26,9 @@ export class Value {
     }
     return val
   }
+  private getFilter (liquid: Liquid, name: string) {
+    const impl = liquid.filters[name]
+    assert(impl || !liquid.options.strictFilters, () => `undefined filter: ${name}`)
+    return impl
+  }
 }

src/tokens/delimited-token.ts

@@ -1,6 +1,6 @@
 import { Token } from './token'
-import { TokenKind } from '../parser/token-kind'
-import { last } from '../util/underscore'
+import { TokenKind } from '../parser'
+import { last } from '../util'
 
 export abstract class DelimitedToken extends Token {
   public trimLeft = false

src/tokens/filter-token.ts

@@ -1,6 +1,6 @@
 import { Token } from './token'
 import { FilterArg } from '../parser/filter-arg'
-import { TokenKind } from '../parser/token-kind'
+import { TokenKind } from '../parser'
 
 export class FilterToken extends Token {
   public constructor (

src/tokens/hash-token.ts

@@ -1,7 +1,7 @@
 import { Token } from './token'
 import { ValueToken } from './value-token'
 import { IdentifierToken } from './identifier-token'
-import { TokenKind } from '../parser/token-kind'
+import { TokenKind } from '../parser'
 
 export class HashToken extends Token {
   constructor (

src/tokens/html-token.ts

@@ -1,5 +1,5 @@
 import { Token } from './token'
-import { TokenKind } from '../parser/token-kind'
+import { TokenKind } from '../parser'
 
 export class HTMLToken extends Token {
   trimLeft = 0

src/tokens/identifier-token.ts

@@ -1,6 +1,6 @@
 import { Token } from './token'
-import { NUMBER, TYPES, SIGN } from '../util/character'
-import { TokenKind } from '../parser/token-kind'
+import { NUMBER, TYPES, SIGN } from '../util'
+import { TokenKind } from '../parser'
 
 export class IdentifierToken extends Token {
   public content: string

src/tokens/index.ts

@@ -0,0 +1,17 @@
+export * from './top-level-token'
+export * from './tag-token'
+export * from './output-token'
+export * from './html-token'
+export * from './number-token'
+export * from './identifier-token'
+export * from './literal-token'
+export * from './operator-token'
+export * from './property-access-token'
+export * from './filter-token'
+export * from './hash-token'
+export * from './quoted-token'
+export * from './token'
+export * from './range-token'
+export * from './value-token'
+export * from './liquid-tag-token'
+export * from './delimited-token'

src/tokens/liquid-tag-token.ts

@@ -1,8 +1,7 @@
 import { DelimitedToken } from './delimited-token'
-import { TokenizationError } from '../util/error'
+import { TokenizationError } from '../util'
 import { NormalizedFullOptions } from '../liquid-options'
-import { TokenKind } from '../parser/token-kind'
-import { Tokenizer } from '../parser/tokenizer'
+import { Tokenizer, TokenKind } from '../parser'
 
 export class LiquidTagToken extends DelimitedToken {
   public name: string

src/tokens/literal-token.ts

@@ -1,5 +1,5 @@
 import { Token } from './token'
-import { TokenKind } from '../parser/token-kind'
+import { TokenKind } from '../parser'
 
 export class LiteralToken extends Token {
   public literal: string

src/tokens/number-token.ts

@@ -1,6 +1,6 @@
 import { Token } from './token'
 import { IdentifierToken } from './identifier-token'
-import { TokenKind } from '../parser/token-kind'
+import { TokenKind } from '../parser'
 
 export class NumberToken extends Token {
   constructor (

src/tokens/operator-token.ts

@@ -1,5 +1,5 @@
 import { Token } from './token'
-import { TokenKind } from '../parser/token-kind'
+import { TokenKind } from '../parser'
 
 export const precedence = {
   '==': 1,

src/tokens/output-token.ts

@@ -1,6 +1,6 @@
 import { DelimitedToken } from './delimited-token'
 import { NormalizedFullOptions } from '../liquid-options'
-import { TokenKind } from '../parser/token-kind'
+import { TokenKind } from '../parser'
 
 export class OutputToken extends DelimitedToken {
   public constructor (

src/tokens/property-access-token.ts

@@ -1,8 +1,7 @@
 import { Token } from './token'
 import { IdentifierToken } from './identifier-token'
 import { QuotedToken } from './quoted-token'
-import { TokenKind } from '../parser/token-kind'
-import { parseStringLiteral } from '../parser/parse-string-literal'
+import { TokenKind, parseStringLiteral } from '../parser'
 
 export class PropertyAccessToken extends Token {
   public propertyName: string

src/tokens/quoted-token.ts

@@ -1,5 +1,5 @@
 import { Token } from './token'
-import { TokenKind } from '../parser/token-kind'
+import { TokenKind } from '../parser'
 
 export class QuotedToken extends Token {
   constructor (

src/tokens/range-token.ts

@@ -1,6 +1,6 @@
 import { Token } from './token'
 import { ValueToken } from './value-token'
-import { TokenKind } from '../parser/token-kind'
+import { TokenKind } from '../parser'
 
 export class RangeToken extends Token {
   constructor (

src/tokens/tag-token.ts

@@ -1,8 +1,7 @@
 import { DelimitedToken } from './delimited-token'
 import { TokenizationError } from '../util/error'
-import { NormalizedFullOptions } from '../liquid-options'
-import { TokenKind } from '../parser/token-kind'
-import { Tokenizer } from '../parser/tokenizer'
+import { Tokenizer, TokenKind } from '../parser'
+import type { NormalizedFullOptions } from '../liquid-options'
 
 export class TagToken extends DelimitedToken {
   public name: string

src/tokens/token.ts

@@ -1,4 +1,4 @@
-import { TokenKind } from '../parser/token-kind'
+import { TokenKind } from '../parser'
 
 export abstract class Token {
   public constructor (

src/tokens/top-level-token.ts

@@ -0,0 +1,5 @@
+import type { TagToken } from './tag-token'
+import type { HTMLToken } from './html-token'
+import type { OutputToken } from './output-token'
+
+export type TopLevelToken = TagToken | OutputToken | HTMLToken

src/tokens/toplevel-token.ts

@@ -1,5 +0,0 @@
-import { TagToken } from './tag-token'
-import { HTMLToken } from './html-token'
-import { OutputToken } from './output-token'
-
-export type TopLevelToken = TagToken | OutputToken | HTMLToken

src/types.ts

@@ -1,32 +0,0 @@
-/* istanbul ignore file */
-import * as TypeGuards from './util/type-guards'
-export { TypeGuards }
-export { ParseError, TokenizationError, AssertionError } from './util/error'
-export { assert } from './util/assert'
-export { Drop } from './drop/drop'
-export { Emitter } from './emitters/emitter'
-export { Expression } from './render/expression'
-export { isFalsy, isTruthy } from './render/boolean'
-export { TagToken } from './tokens/tag-token'
-export { Context } from './context/context'
-export { Template } from './template/template'
-export { FilterImplOptions } from './template/filter/filter-impl-options'
-export { TagImplOptions } from './template/tag/tag-impl-options'
-export { TagImpl } from './template/tag/tag-impl'
-export { ParseStream } from './parser/parse-stream'
-export { Token } from './tokens/token'
-export { TokenKind } from './parser/token-kind'
-export { TopLevelToken } from './tokens/toplevel-token'
-export { Tokenizer } from './parser/tokenizer'
-export { Hash } from './template/tag/hash'
-export { Value } from './template/value'
-// eslint-disable-next-line deprecation/deprecation
-export { _evalToken, evalToken, evalQuotedToken } from './render/expression'
-export { toPromise, toValueSync } from './util/async'
-export { defaultOperators, Operators } from './render/operator'
-export { createTrie, Trie } from './util/operator-trie'
-export { toValue } from './util/underscore'
-export { TimezoneDate } from './util/timezone-date'
-export { filters } from './filters'
-export { tags } from './tags'
-export { defaultOptions } from './liquid-options'

src/util/collection.ts

@@ -1,11 +1,11 @@
 import { isNil, isString, isObject, isArray, isIterable, toValue } from './underscore'
 
-export function toEnumerable (val: any) {
+export function toEnumerable<T = unknown> (val: any): T[] {
   val = toValue(val)
   if (isArray(val)) return val
-  if (isString(val) && val.length > 0) return [val]
+  if (isString(val) && val.length > 0) return [val] as unknown as T[]
   if (isIterable(val)) return Array.from(val)
-  if (isObject(val)) return Object.keys(val).map((key) => [key, val[key]])
+  if (isObject(val)) return Object.keys(val).map((key) => [key, val[key]]) as unknown as T[]
   return []
 }