Class: Foxtail::Syntax::Parser::AST::StringLiteral

Inherits:
BaseLiteral show all
Defined in:
lib/foxtail/syntax/parser/ast/string_literal.rb

Overview

Represents quoted string literals with escape sequence processing

Instance Attribute Summary

Attributes inherited from BaseLiteral

#value

Attributes inherited from SyntaxNode

#span

Attributes inherited from BaseNode

#type

Instance Method Summary collapse

Methods inherited from BaseLiteral

#initialize

Methods inherited from SyntaxNode

#add_span

Methods inherited from BaseNode

#==, #accept, #children, #initialize, #to_h

Constructor Details

This class inherits a constructor from Foxtail::Syntax::Parser::AST::BaseLiteral

Instance Method Details

#parse ⇒ Hash

Parse the string literal value, processing escape sequences Handles backslash escapes, Unicode escapes (uHHHH, UHHHHHH), and validates Unicode scalar values

Returns:

  • (Hash) —

    Hash containing the parsed string value



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# File 'lib/foxtail/syntax/parser/ast/string_literal.rb', line 12

def parse
  # Backslash backslash, backslash double quote, uHHHH, UHHHHHH.
  known_escapes = /(?:\\\\|\\"|\\u(\h{4})|\\U(\h{6}))/

  escaped_value = @value.gsub(known_escapes) {|match|
    codepoint4 = $1
    codepoint6 = $2

    case match
    when "\\\\"
      "\\"
    when '\\"'
      '"'
    else
      codepoint = (codepoint4 || codepoint6).to_i(16)
      if codepoint <= 0xd7ff || 0xe000 <= codepoint
        # It's a Unicode scalar value.
        codepoint.chr(Encoding::UTF_8)
      else
        # Escape sequences representing surrogate code points are
        # well-formed but invalid in Fluent. Replace them with U+FFFD
        # REPLACEMENT CHARACTER.
        "\uFFFD"
      end
    end
  }

  {value: escaped_value}
end