Class | Sass::Script::Lexer |
In: |
lib/sass/script/lexer.rb
|
Parent: | Object |
The lexical analyzer for SassScript. It takes a raw string and converts it to individual tokens that are easier to parse.
Token | = | Struct.new(:type, :value, :line, :offset, :pos) |
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. |
|
OPERATORS | = | { '+' => :plus, '-' => :minus, '*' => :times, '/' => :div, '%' => :mod, '=' => :single_eq, ':' => :colon, '(' => :lparen, ')' => :rparen, ',' => :comma, 'and' => :and, 'or' => :or, 'not' => :not, '==' => :eq, '!=' => :neq, '>=' => :gte, '<=' => :lte, '>' => :gt, '<' => :lt, '#{' => :begin_interpolation, '}' => :end_interpolation, ';' => :semicolon, '{' => :lcurly, } | A hash from operator strings to the corresponding token types. | |
OPERATORS_REVERSE | = | Haml::Util.map_hash(OPERATORS) {|k, v| [v, k]} | ||
TOKEN_NAMES | = | Haml::Util.map_hash(OPERATORS_REVERSE) {|k, v| [k, v.inspect]}.merge({ :const => "variable (e.g. $foo)", :ident => "identifier (e.g. middle)", :bool => "boolean (e.g. true, false)", }) | ||
OP_NAMES | = | OPERATORS.keys.sort_by {|o| -o.size} | A list of operator strings ordered with longer names first so that `>` and `<` don‘t clobber `>=` and `<=`. | |
IDENT_OP_NAMES | = | OP_NAMES.select {|k, v| k =~ /^\w+/} | A sub-list of {OP_NAMES} that only includes operators with identifier names. | |
REGULAR_EXPRESSIONS | = | { :whitespace => /\s+/, :comment => COMMENT, :single_line_comment => SINGLE_LINE_COMMENT, :variable => /([!\$])(#{IDENT})/, :ident => /(#{IDENT})(\()?/, :number => /(-)?(?:(\d*\.\d+)|(\d+))([a-zA-Z%]+)?/, :color => HEXCOLOR, :bool => /(true|false)\b/, :ident_op => %r{(#{Regexp.union(*IDENT_OP_NAMES.map{|s| Regexp.new(Regexp.escape(s) + "(?!#{NMCHAR}|$)")})})}, :op => %r{(#{Regexp.union(*OP_NAMES)})}, } | A hash of regular expressions that are used for tokenizing. | |
STRING_REGULAR_EXPRESSIONS | = | { [:double, false] => string_re('"', '"'), [:single, false] => string_re("'", "'"), [:double, true] => string_re('', '"'), [:single, true] => string_re('', "'"), [:uri, false] => /url\(#{W}(#{URLCHAR}*?)(#{W}\)|#\{)/, [:uri, true] => /(#{URLCHAR}*?)(#{W}\)|#\{)/, } |
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. |
line | [R] |
The line number of the lexer‘s current position.
@return [Fixnum] |
offset | [R] |
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 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
# File lib/sass/script/lexer.rb, line 101 101: def string_re(open, close) 102: /#{open}((?:\\.|\#(?!\{)|[^#{close}\\#])*)(#{close}|#\{)/ 103: 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
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
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
# File lib/sass/script/lexer.rb, line 237 237: def variable 238: _variable(REGULAR_EXPRESSIONS[:variable]) 239: end