class Liquid::Lexer

Constants

COMPARISON_OPERATOR
DOTDOT
DOUBLE_STRING_LITERAL
IDENTIFIER
NUMBER_LITERAL
SINGLE_STRING_LITERAL
SPECIALS

Public Class Methods

new(input) click to toggle source
# File lib/liquid/lexer.rb, line 21
def initialize(input)
  @ss = StringScanner.new(input.rstrip)
end

Public Instance Methods

tokenize() click to toggle source
# File lib/liquid/lexer.rb, line 25
def tokenize
  @output = []

  while !@ss.eos?
    @ss.skip(/\s*/)
    tok = case
    when t = @ss.scan(COMPARISON_OPERATOR) then [:comparison, t]
    when t = @ss.scan(SINGLE_STRING_LITERAL) then [:string, t]
    when t = @ss.scan(DOUBLE_STRING_LITERAL) then [:string, t]
    when t = @ss.scan(NUMBER_LITERAL) then [:number, t]
    when t = @ss.scan(IDENTIFIER) then [:id, t]
    when t = @ss.scan(DOTDOT) then [:dotdot, t]
    else
      c = @ss.getch
      if s = SPECIALS[c]
        [s,c]
      else
        raise SyntaxError, "Unexpected character #{c}"
      end
    end
    @output << tok
  end

  @output << [:end_of_string]
end