Class: Liquid::Expression
- Inherits:
-
Object
- Object
- Liquid::Expression
- Defined in:
- lib/liquid/expression.rb
Constant Summary collapse
- LITERALS =
{ nil => nil, 'nil' => nil, 'null' => nil, '' => nil, 'true' => true, 'false' => false, 'blank' => '', 'empty' => '', # in lax mode, minus sign can be a VariableLookup # For simplicity and performace, we treat it like a literal '-' => VariableLookup.parse("-", nil).freeze, }.freeze
- DOT =
".".ord
- ZERO =
"0".ord
- NINE =
"9".ord
- DASH =
"-".ord
- RANGES_REGEX =
Use an atomic group (?>…) to avoid pathological backtracing from malicious input as described in github.com/Shopify/liquid/issues/1357
/\A\(\s*(?>(\S+)\s*\.\.)\s*(\S+)\s*\)\z/
- INTEGER_REGEX =
/\A(-?\d+)\z/
- FLOAT_REGEX =
/\A(-?\d+)\.\d+\z/
Class Method Summary collapse
- .inner_parse(markup, ss, cache) ⇒ Object
- .parse(markup, ss = StringScanner.new(""), cache = nil) ⇒ Object
- .parse_number(markup, ss) ⇒ Object
Class Method Details
.inner_parse(markup, ss, cache) ⇒ Object
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# File 'lib/liquid/expression.rb', line 53 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, ) end if (num = parse_number(markup, ss)) num else VariableLookup.parse(markup, ss, cache) end end |
.parse(markup, ss = StringScanner.new(""), cache = nil) ⇒ Object
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# File 'lib/liquid/expression.rb', line 31 def parse(markup, ss = StringScanner.new(""), cache = nil) return unless markup markup = markup.strip # markup can be a frozen string if (markup.start_with?('"') && markup.end_with?('"')) || (markup.start_with?("'") && markup.end_with?("'")) return markup[1..-2] elsif LITERALS.key?(markup) return LITERALS[markup] end # Cache only exists during parsing if cache return cache[markup] if cache.key?(markup) cache[markup] = inner_parse(markup, ss, cache).freeze else inner_parse(markup, ss, nil).freeze end end |
.parse_number(markup, ss) ⇒ Object
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# File 'lib/liquid/expression.rb', line 70 def parse_number(markup, ss) # check if the markup is simple integer or float case markup when INTEGER_REGEX return 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 else # number ends with a dot "123." markup.byteslice(0, first_dot_pos).to_f end end |