lib/haml/attribute_parser.rb
# frozen_string_literal: true
require 'haml/ruby_expression'
module Haml
class AttributeParser
class ParseSkip < StandardError
end
# @return [TrueClass, FalseClass] - return true if AttributeParser.parse can be used.
def self.available?
# TruffleRuby doesn't have Ripper.lex
defined?(Ripper) && Ripper.respond_to?(:lex) && Temple::StaticAnalyzer.available?
end
def self.parse(text)
self.new.parse(text)
end
def parse(text)
exp = wrap_bracket(text)
return if Temple::StaticAnalyzer.syntax_error?(exp)
hash = {}
tokens = Ripper.lex(exp)[1..-2] || []
each_attr(tokens) do |attr_tokens|
key = parse_key!(attr_tokens)
hash[key] = attr_tokens.map { |t| t[2] }.join.strip
end
hash
rescue ParseSkip
nil
end
private
def wrap_bracket(text)
text = text.strip
return text if text[0] == '{'
"{#{text}}"
end
def parse_key!(tokens)
_, type, str = tokens.shift
case type
when :on_sp
parse_key!(tokens)
when :on_label
str.tr(':', '')
when :on_symbeg
_, _, key = tokens.shift
assert_type!(tokens.shift, :on_tstring_end) if str != ':'
skip_until_hash_rocket!(tokens)
key
when :on_tstring_beg
_, _, key = tokens.shift
next_token = tokens.shift
unless next_token[1] == :on_label_end
assert_type!(next_token, :on_tstring_end)
skip_until_hash_rocket!(tokens)
end
key
else
raise ParseSkip
end
end
def assert_type!(token, type)
raise ParseSkip if token[1] != type
end
def skip_until_hash_rocket!(tokens)
until tokens.empty?
_, type, str = tokens.shift
break if type == :on_op && str == '=>'
end
end
def each_attr(tokens)
attr_tokens = []
open_tokens = Hash.new { |h, k| h[k] = 0 }
tokens.each do |token|
_, type, _ = token
case type
when :on_comma
if open_tokens.values.all?(&:zero?)
yield(attr_tokens)
attr_tokens = []
next
end
when :on_lbracket
open_tokens[:array] += 1
when :on_rbracket
open_tokens[:array] -= 1
when :on_lbrace
open_tokens[:block] += 1
when :on_rbrace
open_tokens[:block] -= 1
when :on_lparen
open_tokens[:paren] += 1
when :on_rparen
open_tokens[:paren] -= 1
when :on_embexpr_beg
open_tokens[:embexpr] += 1
when :on_embexpr_end
open_tokens[:embexpr] -= 1
when :on_sp
next if attr_tokens.empty?
end
attr_tokens << token
end
yield(attr_tokens) unless attr_tokens.empty?
end
end
end