136 lines
3.5 KiB
Ruby
136 lines
3.5 KiB
Ruby
require 'strscan'
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module Sass
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module Script
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class Lexer # :nodoc:
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Token = Struct.new(:type, :value, :line, :offset)
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OPERATORS = {
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'+' => :plus,
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'-' => :minus,
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'*' => :times,
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'/' => :div,
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'%' => :mod,
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'(' => :lparen,
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')' => :rparen,
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',' => :comma,
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'and' => :and,
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'or' => :or,
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'not' => :not,
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'==' => :eq,
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'!=' => :neq,
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'>=' => :gte,
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'<=' => :lte,
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'>' => :gt,
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'<' => :lt,
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}
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# We'll want to match longer names first
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# so that > and < don't clobber >= and <=
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OP_NAMES = OPERATORS.keys.sort_by {|o| -o.size}
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REGULAR_EXPRESSIONS = {
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:whitespace => /\s*/,
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:variable => /!(\w+)/,
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:ident => /(\\.|[^\s\\+\-*\/%(),=!])+/,
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:string => /"((?:\\.|[^"\\])*)"/,
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:number => /(-)?(?:(\d*\.\d+)|(\d+))([a-zA-Z%]+)?/,
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:color => /\##{"([0-9a-fA-F]{1,2})" * 3}|(#{Color::HTML4_COLORS.keys.join("|")})/,
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:bool => /(true|false)\b/,
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:op => %r{(#{Regexp.union(*OP_NAMES.map{|s| Regexp.new(Regexp.escape(s) + (s =~ /\w$/ ? '(?:\b|$)' : ''))})})}
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}
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def initialize(str, line, offset)
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@scanner = StringScanner.new(str)
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@line = line
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@offset = offset
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end
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def token
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if @tok
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@tok, tok = nil, @tok
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return tok
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end
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return if done?
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value = variable || string || number || color || bool || op || ident
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unless value
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raise SyntaxError.new("Syntax error in '#{@scanner.string}' at character #{current_position}.")
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end
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Token.new(value.first, value.last, @line, last_match_position)
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end
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def peek
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@tok ||= token
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end
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def done?
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whitespace
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@scanner.eos? && @tok.nil?
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end
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def rest
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@scanner.rest
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end
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private
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def whitespace
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@scanner.scan(REGULAR_EXPRESSIONS[:whitespace])
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end
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def variable
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return unless @scanner.scan(REGULAR_EXPRESSIONS[:variable])
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[:const, @scanner[1]]
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end
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def ident
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return unless s = @scanner.scan(REGULAR_EXPRESSIONS[:ident])
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[:ident, s.gsub(/\\(.)/, '\1')]
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end
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def string
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return unless @scanner.scan(REGULAR_EXPRESSIONS[:string])
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[:string, Script::String.new(@scanner[1].gsub(/\\([^0-9a-f])/, '\1').gsub(/\\([0-9a-f]{1,4})/, "\\\\\\1"))]
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end
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def number
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return unless @scanner.scan(REGULAR_EXPRESSIONS[:number])
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value = @scanner[2] ? @scanner[2].to_f : @scanner[3].to_i
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value = -value if @scanner[1]
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[:number, Script::Number.new(value, Array(@scanner[4]))]
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end
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def color
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return unless @scanner.scan(REGULAR_EXPRESSIONS[:color])
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value = if @scanner[4]
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color = Color::HTML4_COLORS[@scanner[4].downcase]
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else
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(1..3).map {|i| @scanner[i]}.map {|num| num.ljust(2, num).to_i(16)}
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end
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[:color, Script::Color.new(value)]
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end
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def bool
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return unless s = @scanner.scan(REGULAR_EXPRESSIONS[:bool])
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[:bool, Script::Bool.new(s == 'true')]
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end
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def op
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return unless op = @scanner.scan(REGULAR_EXPRESSIONS[:op])
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[OPERATORS[op]]
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end
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protected
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def current_position
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@offset + @scanner.pos + 1
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end
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def last_match_position
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current_position - @scanner.matchedsize
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end
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end
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end
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end
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