class Liquid::Expression

Constants

FLOATS_REGEX
INTEGERS_REGEX
LITERALS
RANGES_REGEX

Use an atomic group (?>…) to avoid pathological backtracing from malicious input as described in github.com/Shopify/liquid/issues/1357

Public Class Methods

parse(markup) click to toggle source
# File lib/liquid/expression.rb, line 20
def self.parse(markup)
  return nil unless markup

  markup = markup.strip
  if (markup.start_with?('"') && markup.end_with?('"')) ||
     (markup.start_with?("'") && markup.end_with?("'"))
    return markup[1..-2]
  end

  case markup
  when INTEGERS_REGEX
    Regexp.last_match(1).to_i
  when RANGES_REGEX
    RangeLookup.parse(Regexp.last_match(1), Regexp.last_match(2))
  when FLOATS_REGEX
    Regexp.last_match(1).to_f
  else
    if LITERALS.key?(markup)
      LITERALS[markup]
    else
      VariableLookup.parse(markup)
    end
  end
end