Class: Sass::Script::Lexer
- Inherits:
-
Object
- Object
- Sass::Script::Lexer
- Includes:
- Sass::SCSS::RX
- Defined in:
- /var/www/sass-pages/.haml/lib/sass/script/lexer.rb
Overview
The lexical analyzer for SassScript. It takes a raw string and converts it to individual tokens that are easier to parse.
Direct Known Subclasses
Constant Summary
Instance Attribute Summary
- - (Fixnum) line readonly The line number of the lexer’s current position.
- - (Fixnum) offset readonly The number of bytes into the current line of the lexer’s current position.
Instance Method Summary
-
- (Boolean) after_interpolation?
Whether or not the last token lexed was
:end_interpolation. - - (Boolean) done? Whether or not there’s more source text to lex.
-
- expected!(name)
Raise an error to the effect that
namewas expected in the input stream and wasn’t found. - - (Lexer) initialize(str, line, offset, options) constructor A new instance of Lexer.
- - (Token) next Moves the lexer forward one token.
- - (Token) peek Returns the next token without moving the lexer forward.
- - (String) str { ... } Records all non-comment text the lexer consumes within the block and returns it as a string.
- - unpeek! Rewinds the underlying StringScanner to before the token returned by #peek.
- - (Boolean) whitespace?(tok = @tok) Returns whether or not there’s whitespace before the next token.
Methods included from Sass::SCSS::RX
Constructor Details
- (Lexer) initialize(str, line, offset, options)
A new instance of Lexer
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# File '/var/www/sass-pages/.haml/lib/sass/script/lexer.rb', line 128
def initialize(str, line, offset, options)
@scanner = str.is_a?(StringScanner) ? str : StringScanner.new(str)
@line = line
@offset = offset
@options = options
@interpolation_stack = []
@prev = nil
end
|
Instance Attribute Details
- (Fixnum) line (readonly)
The line number of the lexer’s current position.
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# File '/var/www/sass-pages/.haml/lib/sass/script/lexer.rb', line 34
def line
@line
end
|
- (Fixnum) offset (readonly)
The number of bytes into the current line of the lexer’s current position.
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# File '/var/www/sass-pages/.haml/lib/sass/script/lexer.rb', line 40
def offset
@offset
end
|
Instance Method Details
- (Boolean) after_interpolation?
Whether or not the last token lexed was :end_interpolation.
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# File '/var/www/sass-pages/.haml/lib/sass/script/lexer.rb', line 179
def after_interpolation?
@prev && @prev.type == :end_interpolation
end
|
- (Boolean) done?
Whether or not there’s more source text to lex.
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# File '/var/www/sass-pages/.haml/lib/sass/script/lexer.rb', line 173
def done?
whitespace unless after_interpolation? && @interpolation_stack.last
@scanner.eos? && @tok.nil?
end
|
- expected!(name)
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.
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# File '/var/www/sass-pages/.haml/lib/sass/script/lexer.rb', line 191
def expected!(name)
unpeek!
Sass::SCSS::Parser.expected(@scanner, name, @line)
end
|
- (Token) next
Moves the lexer forward one token.
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# File '/var/www/sass-pages/.haml/lib/sass/script/lexer.rb', line 140
def next
@tok ||= read_token
@tok, tok = nil, @tok
@prev = tok
return tok
end
|
- (Token) peek
Returns the next token without moving the lexer forward.
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# File '/var/www/sass-pages/.haml/lib/sass/script/lexer.rb', line 162
def peek
@tok ||= read_token
end
|
- (String) str { ... }
Records all non-comment text the lexer consumes within the block and returns it as a string.
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# File '/var/www/sass-pages/.haml/lib/sass/script/lexer.rb', line 201
def str
old_pos = @tok ? @tok.pos : @scanner.pos
yield
new_pos = @tok ? @tok.pos : @scanner.pos
@scanner.string[old_pos...new_pos]
end
|
- unpeek!
Rewinds the underlying StringScanner to before the token returned by #peek.
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# File '/var/www/sass-pages/.haml/lib/sass/script/lexer.rb', line 168
def unpeek!
@scanner.pos = @tok.pos if @tok
end
|
- (Boolean) whitespace?(tok = @tok)
Returns whether or not there’s whitespace before the next token.
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# File '/var/www/sass-pages/.haml/lib/sass/script/lexer.rb', line 150
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
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