WIP2

History.md

@@ -2,8 +2,6 @@
 
 ## 6.0.0
 
-### Architectural changes
-
 ### Features
 * (TODO) Add support for boolean expressions everywhere
   * As variable output `{{ a or b }}`
@@ -21,16 +19,28 @@
 - (TODO) Add support for parenthesized expressions
   * e.g. `(a or b) and c`
 
+### Architectural changes
+* `parse_expression` and `safe_parse_expression` have been removed from `Tag` and `ParseContext`
+* `Parser` methods now produce AST nodes instead of strings
+  * `Parser#expression` produces a value,
+  * `Parser#string` produces a string,
+  * etc.
+
 ### Breaking changes
-* We are removing the Environment's `error_mode` option.
+* The Environment's `error_mode` option has been removed.
   * `:warn` is no longer supported
   * `:lax` and `lax_parse` is no longer supported
   * `:strict` and `strict_parse` is no longer supported
   * `strict2_parse` is renamed to `parse_markup`
+* The `warnings` system has been removed.
+* `Parser#expression` is renamed to `Parser#expression_string`
+* `safe_parse_expression` methods are replaced by `Parser#expression`
+* `parse_expression` methods are replaced by `Parser#unsafe_parse_expression`
 
 ### Migrating from `^5.11.0`
 - In custom tags that include `ParserSwitching`, rename `strict2_parse` to `parse_markup`
 - Remove code depending on `:error_mode`
+- Replace `safe_parse_expression` calls with `Parser#expression`
 
 ## 5.11.0
 * Revert the Inline Snippets tag (#2001), treat its inclusion in the latest Liquid release as a bug, and allow for feedback on RFC#1916 to better support Liquid developers [Guilherme Carreiro]

lib/liquid/condition.rb

@@ -48,8 +48,9 @@ def self.operators
       @@operators
     end
 
-    def self.parse_expression(parse_context, markup, safe: false)
-      @@method_literals[markup] || parse_context.parse_expression(markup, safe: safe)
+    def self.parse_expression(parser)
+      markup = parser.expression_string
+      @@method_literals[markup] || parser.unsafe_parse_expression(markup)
     end
 
     attr_reader :attachment, :child_condition

lib/liquid/context.rb

@@ -60,10 +60,6 @@ def initialize(environments = {}, outer_scope = {}, registers = {}, rethrow_erro
     end
     # rubocop:enable Metrics/ParameterLists
 
-    def warnings
-      @warnings ||= []
-    end
-
     def strainer
       @strainer ||= @environment.create_strainer(self, @filters)
     end
@@ -157,7 +153,6 @@ def new_isolated_subcontext
         subcontext.filters  = @filters
         subcontext.strainer = nil
         subcontext.errors   = errors
-        subcontext.warnings = warnings
         subcontext.disabled_tags = @disabled_tags
       end
     end
@@ -180,7 +175,8 @@ def []=(key, value)
     # Example:
     #   products == empty #=> products.empty?
     def [](expression)
-      evaluate(Expression.parse(expression, @string_scanner))
+      @string_scanner.string = expression
+      evaluate(Parser.new(@string_scanner).expression)
     end
 
     def key?(key)
@@ -244,7 +240,7 @@ def tag_disabled?(tag_name)
 
     protected
 
-    attr_writer :base_scope_depth, :warnings, :errors, :strainer, :filters, :disabled_tags
+    attr_writer :base_scope_depth, :errors, :strainer, :filters, :disabled_tags
 
     private
 

lib/liquid/expression.rb

@@ -25,10 +25,6 @@ class Expression
     FLOAT_REGEX = /\A(-?\d+)\.\d+\z/
 
     class << self
-      def safe_parse(parser, ss = StringScanner.new(""), cache = nil)
-        parse(parser.expression, ss, cache)
-      end
-
       def parse(markup, ss = StringScanner.new(""), cache = nil)
         return unless markup
 
@@ -52,72 +48,35 @@ def parse(markup, ss = StringScanner.new(""), cache = nil)
       end
 
       def inner_parse(markup, ss, cache)
-        if markup.start_with?("(") && markup.end_with?(")") && markup =~ RANGES_REGEX
-          return RangeLookup.parse(
-            Regexp.last_match(1),
-            Regexp.last_match(2),
-            ss,
-            cache,
+        if (markup.start_with?("(") && markup.end_with?(")")) && markup =~ RANGES_REGEX
+          start_markup = Regexp.last_match(1)
+          end_markup = Regexp.last_match(2)
+          start_obj = parse(start_markup, ss, cache)
+          end_obj = parse(end_markup, ss, cache)
+          return RangeLookup.create(
+            start_obj,
+            end_obj,
+            start_markup,
+            end_markup,
           )
         end
 
-        if (num = parse_number(markup, ss))
+        if (num = parse_number(markup))
           num
         else
           VariableLookup.parse(markup, ss, cache)
         end
       end
 
-      def parse_number(markup, ss)
+      def parse_number(markup)
         # check if the markup is simple integer or float
         case markup
         when INTEGER_REGEX
-          return Integer(markup, 10)
+          Integer(markup, 10)
         when FLOAT_REGEX
-          return markup.to_f
-        end
-
-        ss.string = markup
-        # the first byte must be a digit or  a dash
-        byte = ss.scan_byte
-
-        return false if byte != DASH && (byte < ZERO || byte > NINE)
-
-        if byte == DASH
-          peek_byte = ss.peek_byte
-
-          # if it starts with a dash, the next byte must be a digit
-          return false if peek_byte.nil? || !(peek_byte >= ZERO && peek_byte <= NINE)
-        end
-
-        # The markup could be a float with multiple dots
-        first_dot_pos = nil
-        num_end_pos = nil
-
-        while (byte = ss.scan_byte)
-          return false if byte != DOT && (byte < ZERO || byte > NINE)
-
-          # we found our number and now we are just scanning the rest of the string
-          next if num_end_pos
-
-          if byte == DOT
-            if first_dot_pos.nil?
-              first_dot_pos = ss.pos
-            else
-              # we found another dot, so we know that the number ends here
-              num_end_pos = ss.pos - 1
-            end
-          end
-        end
-
-        num_end_pos = markup.length if ss.eos?
-
-        if num_end_pos
-          # number ends with a number "123.123"
-          markup.byteslice(0, num_end_pos).to_f
+          markup.to_f
         else
-          # number ends with a dot "123."
-          markup.byteslice(0, first_dot_pos).to_f
+          false
         end
       end
     end

lib/liquid/parse_context.rb

@@ -3,14 +3,13 @@
 module Liquid
   class ParseContext
     attr_accessor :locale, :line_number, :trim_whitespace, :depth
-    attr_reader :partial, :warnings, :environment
+    attr_reader :partial, :environment
 
     def initialize(options = Const::EMPTY_HASH)
       @environment = options.fetch(:environment, Environment.default)
       @template_options = options ? options.dup : {}
 
-      @locale   = @template_options[:locale] ||= I18n.new
-      @warnings = []
+      @locale = @template_options[:locale] ||= I18n.new
 
       # constructing new StringScanner in Lexer, Tokenizer, etc is expensive
       # This StringScanner will be shared by all of them
@@ -38,7 +37,7 @@ def new_block_body
 
     def new_parser(input)
       @string_scanner.string = input
-      Parser.new(@string_scanner)
+      Parser.new(@string_scanner, @expression_cache)
     end
 
     def new_tokenizer(source, start_line_number: nil, for_liquid_tag: false)
@@ -50,21 +49,6 @@ def new_tokenizer(source, start_line_number: nil, for_liquid_tag: false)
       )
     end
 
-    def safe_parse_expression(parser)
-      Expression.safe_parse(parser, @string_scanner, @expression_cache)
-    end
-
-    def parse_expression(markup, safe: false)
-      # markup MUST come from a string returned by the parser
-      # (e.g., parser.expression). We're not calling the parser here to
-      # prevent redundant parser overhead. The `safe` opt-in
-      # exists to ensure it is not accidentally still called with
-      # the result of a regex.
-      raise Liquid::InternalError, "unsafe parse_expression cannot be used" unless safe
-
-      Expression.parse(markup, @string_scanner, @expression_cache)
-    end
-
     def partial=(value)
       @partial = value
       @options = value ? partial_options : @template_options