Move to_integer, to_date, and to_number to Liquid::Utils

lib/liquid/utils.rb

@@ -32,5 +32,48 @@ module Liquid
 
       segments
     end
+
+    def self.to_integer(num)
+      return num if num.is_a?(Integer)
+      num = num.to_s
+      begin
+        Integer(num)
+      rescue ::ArgumentError
+        raise Liquid::ArgumentError, "invalid integer"
+      end
+    end
+
+    def self.to_number(obj)
+      case obj
+      when Float
+        BigDecimal.new(obj.to_s)
+      when Numeric
+        obj
+      when String
+        (obj.strip =~ /\A\d+\.\d+\z/) ? BigDecimal.new(obj) : obj.to_i
+      else
+        0
+      end
+    end
+
+    def self.to_date(obj)
+      return obj if obj.respond_to?(:strftime)
+
+      if obj.is_a?(String)
+        return nil if obj.empty?
+        obj = obj.downcase
+      end
+
+      case obj
+      when 'now'.freeze, 'today'.freeze
+        Time.now
+      when /\A\d+\z/, Integer
+        Time.at(obj.to_i)
+      when String
+        Time.parse(obj)
+      end
+    rescue ArgumentError
+      nil
+    end
   end
 end