The lexical analyzer for SassScript. It takes a raw string and converts it to individual tokens that are easier to parse.
A sub-list of {OP_NAMES} that only includes operators with identifier names.
A hash from operator strings to the corresponding token types.
A list of operator strings ordered with longer names first so that `>` and `<` don't clobber `>=` and `<=`.
A hash of regular expressions that are used for tokenizing.
A hash of regular expressions that are used for tokenizing strings.
The key is a `[Symbol, Boolean]` pair. The symbol represents which style of quotation to use, while the boolean represents whether or not the string is following an interpolated segment.
A struct containing information about an individual token.
`type`: [`Symbol`] : The type of token.
`value`: [`Object`] : The Ruby object corresponding to the value of the token.
`line`: [`Fixnum`] : The line of the source file on which the token appears.
`offset`: [`Fixnum`] : The number of bytes into the line the SassScript token appeared.
`pos`: [`Fixnum`] : The scanner position at which the SassScript token appeared.
The line number of the lexer's current position.
@return [Fixnum]
The number of bytes into the current line of the lexer's current position.
@return [Fixnum]
@param str [String, StringScanner] The source text to lex @param line [Fixnum] The line on which the SassScript appears.
Used for error reporting
@param offset [Fixnum] The number of characters in on which the SassScript appears.
Used for error reporting
@param options [{Symbol => Object}] An options hash;
see {file:SASS_REFERENCE.md#sass_options the Sass options documentation}
# File lib/sass/script/lexer.rb, line 131 def initialize(str, line, offset, options) @scanner = str.is_a?(StringScanner) ? str : Sass::Util::MultibyteStringScanner.new(str) @line = line @offset = offset @options = options @interpolation_stack = [] @prev = nil end
# File lib/sass/script/lexer.rb, line 98 def string_re(open, close) /#{open}((?:\.|\#(?!\{)|[^#{close}\#])*)(#{close}|#\{)/ end
@return [Boolean] Whether or not the last token lexed was `:end_interpolation`.
# File lib/sass/script/lexer.rb, line 182 def after_interpolation? @prev && @prev.type == :end_interpolation end
@return [Boolean] Whether or not there's more source text to lex.
# File lib/sass/script/lexer.rb, line 176 def done? whitespace unless after_interpolation? && @interpolation_stack.last @scanner.eos? && @tok.nil? end
Raise an error to the effect that `name` was expected in the input stream and wasn't found.
This calls {#unpeek!} to rewind the scanner to immediately after the last returned token.
@param name [String] The name of the entity that was expected but not found @raise [Sass::SyntaxError]
# File lib/sass/script/lexer.rb, line 194 def expected!(name) unpeek! Sass::SCSS::Parser.expected(@scanner, name, @line) end
Moves the lexer forward one token.
@return [Token] The token that was moved past
# File lib/sass/script/lexer.rb, line 143 def next @tok ||= read_token @tok, tok = nil, @tok @prev = tok return tok end
Returns the next token without moving the lexer forward.
@return [Token] The next token
# File lib/sass/script/lexer.rb, line 165 def peek @tok ||= read_token end
Records all non-comment text the lexer consumes within the block and returns it as a string.
@yield A block in which text is recorded @return [String]
# File lib/sass/script/lexer.rb, line 204 def str old_pos = @tok ? @tok.pos : @scanner.pos yield new_pos = @tok ? @tok.pos : @scanner.pos @scanner.string[old_pos...new_pos] end
Rewinds the underlying StringScanner to before the token returned by {#peek}.
# File lib/sass/script/lexer.rb, line 171 def unpeek! @scanner.pos = @tok.pos if @tok end
Returns whether or not there's whitespace before the next token.
@return [Boolean]
# File lib/sass/script/lexer.rb, line 153 def whitespace?(tok = @tok) if tok @scanner.string[0...tok.pos] =~ /\s\Z/ else @scanner.string[@scanner.pos, 1] =~ /^\s/ || @scanner.string[@scanner.pos - 1, 1] =~ /\s\Z/ end end
# File lib/sass/script/lexer.rb, line 244 def _variable(rx) return unless scan(rx) [:const, @scanner[2]] end
# File lib/sass/script/lexer.rb, line 250 def ident return unless scan(REGULAR_EXPRESSIONS[:ident]) [@scanner[2] ? :funcall : :ident, @scanner[1]] end
# File lib/sass/script/lexer.rb, line 213 def read_token return if done? return unless value = token type, val, size = value size ||= @scanner.matched_size val.line = @line if val.is_a?(Script::Node) Token.new(type, val, @line, current_position - size, @scanner.pos - size) end
# File lib/sass/script/lexer.rb, line 255 def string(re, open) return unless scan(STRING_REGULAR_EXPRESSIONS[[re, open]]) if @scanner[2] == '#{' #' @scanner.pos -= 2 # Don't actually consume the #{ @interpolation_stack << re end str = if re == :uri Script::String.new("#{'url(' unless open}#{@scanner[1]}#{')' unless @scanner[2] == '#{'}") else Script::String.new(@scanner[1].gsub(/\\(['"]|\#\{)/, '\1'), :string) end [:string, str] end def number return unless scan(REGULAR_EXPRESSIONS[:number]) value = @scanner[2] ? @scanner[2].to_f : @scanner[3].to_i value = -value if @scanner[1] [:number, Script::Number.new(value, Array(@scanner[4]))] end def color return unless s = scan(REGULAR_EXPRESSIONS[:color]) raise Sass::SyntaxError.new(<<MESSAGE.rstrip) unless s.size == 4 || s.size == 7 Colors must have either three or six digits: '#{s}' MESSAGE value = s.scan(/^#(..?)(..?)(..?)$/).first. map {|num| num.ljust(2, num).to_i(16)} [:color, Script::Color.new(value)] end def special_fun return unless str1 = scan(/((-[\w-]+-)?(calc|element)|expression|progid:[a-z\.]*)\(/i) str2, _ = Sass::Shared.balance(@scanner, ?(, ?), 1) c = str2.count("\n") old_line = @line old_offset = @offset @line += c @offset = (c == 0 ? @offset + str2.size : str2[/\n(.*)/, 1].size) [:special_fun, Sass::Util.merge_adjacent_strings( [str1] + Sass::Engine.parse_interp(str2, old_line, old_offset, @options)), str1.size + str2.size] end def special_val return unless scan(/!important/i) [:string, Script::String.new("!important")] end def ident_op return unless op = scan(REGULAR_EXPRESSIONS[:ident_op]) [OPERATORS[op]] end def op return unless op = scan(REGULAR_EXPRESSIONS[:op]) @interpolation_stack << nil if op == :begin_interpolation [OPERATORS[op]] end def raw(rx) return unless val = scan(rx) [:raw, val] end def scan(re) return unless str = @scanner.scan(re) c = str.count("\n") @line += c @offset = (c == 0 ? @offset + str.size : str[/\n(.*)/, 1].size) str end def current_position @offset + 1 end end end end
# File lib/sass/script/lexer.rb, line 230 def token if after_interpolation? && (interp_type = @interpolation_stack.pop) return string(interp_type, true) end variable || string(:double, false) || string(:single, false) || number || color || string(:uri, false) || raw(UNICODERANGE) || special_fun || special_val || ident_op || ident || op end
# File lib/sass/script/lexer.rb, line 240 def variable _variable(REGULAR_EXPRESSIONS[:variable]) end
# File lib/sass/script/lexer.rb, line 224 def whitespace nil while scan(REGULAR_EXPRESSIONS[:whitespace]) || scan(REGULAR_EXPRESSIONS[:comment]) || scan(REGULAR_EXPRESSIONS[:single_line_comment]) end