class Liquid::Parser
Public Class Methods
new(input)
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# File lib/liquid/parser.rb, line 3 def initialize(input) l = Lexer.new(input) @tokens = l.tokenize @p = 0 # pointer to current location end
Public Instance Methods
argument()
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# File lib/liquid/parser.rb, line 65 def argument str = "" # might be a keyword argument (identifier: expression) if look(:id) && look(:colon, 1) str << consume << consume << ' '.freeze end str << expression str end
consume(type = nil)
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# File lib/liquid/parser.rb, line 13 def consume(type = nil) token = @tokens[@p] if type && token[0] != type raise SyntaxError, "Expected #{type} but found #{@tokens[@p].first}" end @p += 1 token[1] end
consume?(type)
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Only consumes the token if it matches the type Returns the token's contents if it was consumed or false otherwise.
# File lib/liquid/parser.rb, line 25 def consume?(type) token = @tokens[@p] return false unless token && token[0] == type @p += 1 token[1] end
expression()
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# File lib/liquid/parser.rb, line 47 def expression token = @tokens[@p] if token[0] == :id variable_signature elsif [:string, :number].include? token[0] consume elsif token.first == :open_round consume first = expression consume(:dotdot) last = expression consume(:close_round) "(#{first}..#{last})" else raise SyntaxError, "#{token} is not a valid expression" end end
id?(str)
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Like consume? Except for an :id token of a certain name
# File lib/liquid/parser.rb, line 33 def id?(str) token = @tokens[@p] return false unless token && token[0] == :id return false unless token[1] == str @p += 1 token[1] end
jump(point)
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# File lib/liquid/parser.rb, line 9 def jump(point) @p = point end
look(type, ahead = 0)
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# File lib/liquid/parser.rb, line 41 def look(type, ahead = 0) tok = @tokens[@p + ahead] return false unless tok tok[0] == type end
variable_signature()
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# File lib/liquid/parser.rb, line 76 def variable_signature str = consume(:id) if look(:open_square) str << consume str << expression str << consume(:close_square) end if look(:dot) str << consume str << variable_signature end str end