The lexical analyzer for SassScript. It takes a raw string and converts it to individual tokens that are easier to parse.
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.
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 sub-list of {OP_NAMES} that only includes operators with identifier names.
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.
@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 128
128: def initialize(str, line, offset, options)
129: @scanner = str.is_a?(StringScanner) ? str : StringScanner.new(str)
130: @line = line
131: @offset = offset
132: @options = options
133: @interpolation_stack = []
134: @prev = nil
135: end
@return [Boolean] Whether or not the last token lexed was `:end_interpolation`.
# File lib/sass/script/lexer.rb, line 179
179: def after_interpolation?
180: @prev && @prev.type == :end_interpolation
181: end
@return [Boolean] Whether or not there’s more source text to lex.
# File lib/sass/script/lexer.rb, line 173
173: def done?
174: whitespace unless after_interpolation? && @interpolation_stack.last
175: @scanner.eos? && @tok.nil?
176: 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 191
191: def expected!(name)
192: unpeek!
193: Sass::SCSS::Parser.expected(@scanner, name, @line)
194: end
Moves the lexer forward one token.
@return [Token] The token that was moved past
# File lib/sass/script/lexer.rb, line 140
140: def next
141: @tok ||= read_token
142: @tok, tok = nil, @tok
143: @prev = tok
144: return tok
145: end
Returns the next token without moving the lexer forward.
@return [Token] The next token
# File lib/sass/script/lexer.rb, line 162
162: def peek
163: @tok ||= read_token
164: 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 201
201: def str
202: old_pos = @tok ? @tok.pos : @scanner.pos
203: yield
204: new_pos = @tok ? @tok.pos : @scanner.pos
205: @scanner.string[old_pos...new_pos]
206: end
Rewinds the underlying StringScanner to before the token returned by {#peek}.
# File lib/sass/script/lexer.rb, line 168
168: def unpeek!
169: @scanner.pos = @tok.pos if @tok
170: end
Returns whether or not there’s whitespace before the next token.
@return [Boolean]
# File lib/sass/script/lexer.rb, line 150
150: def whitespace?(tok = @tok)
151: if tok
152: @scanner.string[0...tok.pos] =~ /\s\Z/
153: else
154: @scanner.string[@scanner.pos, 1] =~ /^\s/ ||
155: @scanner.string[@scanner.pos - 1, 1] =~ /\s\Z/
156: end
157: end
# File lib/sass/script/lexer.rb, line 241
241: def _variable(rx)
242: line = @line
243: offset = @offset
244: return unless scan(rx)
245: if @scanner[1] == '!' && @scanner[2] != 'important'
246: Script.var_warning(@scanner[2], line, offset + 1, @options[:filename])
247: end
248:
249: [:const, @scanner[2]]
250: end
# File lib/sass/script/lexer.rb, line 252
252: def ident
253: return unless scan(REGULAR_EXPRESSIONS[:ident])
254: [@scanner[2] ? :funcall : :ident, @scanner[1]]
255: end
# File lib/sass/script/lexer.rb, line 210
210: def read_token
211: return if done?
212: return unless value = token
213: type, val, size = value
214: size ||= @scanner.matched_size
215:
216: val.line = @line if val.is_a?(Script::Node)
217: Token.new(type, val, @line,
218: current_position - size, @scanner.pos - size)
219: end
# File lib/sass/script/lexer.rb, line 257
257: def string(re, open)
258: return unless scan(STRING_REGULAR_EXPRESSIONS[[re, open]])
259: if @scanner[2] == '#{' #'
260: @scanner.pos -= 2 # Don't actually consume the #{
261: @interpolation_stack << re
262: end
263: str =
264: if re == :uri
265: Script::String.new("#{'url(' unless open}#{@scanner[1]}#{')' unless @scanner[2] == '#{'}")
266: else
267: Script::String.new(@scanner[1].gsub(/\\(['"]|\#\{)/, '\1'), :string)
268: end
269: [:string, str]
270: end
271:
272: def number
273: return unless scan(REGULAR_EXPRESSIONS[:number])
274: value = @scanner[2] ? @scanner[2].to_f : @scanner[3].to_i
275: value = -value if @scanner[1]
276: [:number, Script::Number.new(value, Array(@scanner[4]))]
277: end
278:
279: def color
280: return unless s = scan(REGULAR_EXPRESSIONS[:color])
281: raise Sass::SyntaxError.new(<<MESSAGE) unless s.size == 4 || s.size == 7
282: Colors must have either three or six digits: '#{s}'
283: MESSAGE
284: value = s.scan(/^#(..?)(..?)(..?)$/).first.
285: map {|num| num.ljust(2, num).to_i(16)}
286: [:color, Script::Color.new(value)]
287: end
288:
289: def bool
290: return unless s = scan(REGULAR_EXPRESSIONS[:bool])
291: [:bool, Script::Bool.new(s == 'true')]
292: end
293:
294: def special_fun
295: return unless str1 = scan(/((-[\w-]+-)?calc|expression|progid:[a-z\.]*)\(/i)
296: str2, _ = Haml::Shared.balance(@scanner, ?(, ?), 1)
297: c = str2.count("\n")
298: old_line = @line
299: old_offset = @offset
300: @line += c
301: @offset = (c == 0 ? @offset + str2.size : str2[/\n(.*)/, 1].size)
302: [:special_fun,
303: Haml::Util.merge_adjacent_strings(
304: [str1] + Sass::Engine.parse_interp(str2, old_line, old_offset, @options)),
305: str1.size + str2.size]
306: end
307:
308: def ident_op
309: return unless op = scan(REGULAR_EXPRESSIONS[:ident_op])
310: [OPERATORS[op]]
311: end
312:
313: def op
314: return unless op = scan(REGULAR_EXPRESSIONS[:op])
315: @interpolation_stack << nil if op == :begin_interpolation
316: [OPERATORS[op]]
317: end
318:
319: def raw(rx)
320: return unless val = scan(rx)
321: [:raw, val]
322: end
323:
324: def scan(re)
325: return unless str = @scanner.scan(re)
326: c = str.count("\n")
327: @line += c
328: @offset = (c == 0 ? @offset + str.size : str[/\n(.*)/, 1].size)
329: str
330: end
331:
332: def current_position
333: @offset + 1
334: end
335: end
336: end
337: end
338:
# File lib/sass/script/lexer.rb, line 227
227: def token
228: if after_interpolation? && (interp_type = @interpolation_stack.pop)
229: return string(interp_type, true)
230: end
231:
232: variable || string(:double, false) || string(:single, false) || number ||
233: color || bool || string(:uri, false) || raw(UNICODERANGE) ||
234: special_fun || ident_op || ident || op
235: end
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