Class: Sass::Script::Parser

Inherits:
Object
  • Object
show all
Defined in:
.ruby-sass/lib/sass/script/parser.rb

Overview

The parser for SassScript. It parses a string of code into a tree of Tree::Nodes.

Direct Known Subclasses

CssParser

Direct Known Subclasses

CssParser

Constant Summary

PRECEDENCE = 
[
  :comma, :single_eq, :space, :or, :and,
  [:eq, :neq],
  [:gt, :gte, :lt, :lte],
  [:plus, :minus],
  [:times, :div, :mod],
]
ASSOCIATIVE = 
[:plus, :times]

Class Method Summary (collapse)

Instance Method Summary (collapse)

Constructor Details

#initialize(str, line, offset, options = {}) ⇒ Parser

Returns a new instance of Parser

Parameters:

  • str (String, StringScanner) —

    The source text to parse

  • line (Integer) —

    The line on which the SassScript appears. Used for error reporting and sourcemap building

  • offset (Integer) —

    The character (not byte) offset where the script starts in the line. Used for error reporting and sourcemap building

  • options ({Symbol => Object}) (defaults to: {}) —

    An options hash; see the Sass options documentation. This supports an additional `:allow_extra_text` option that controls whether the parser throws an error when extra text is encountered after the parsed construct.



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# File '.ruby-sass/lib/sass/script/parser.rb', line 32

def initialize(str, line, offset, options = {})
  @options = options
  @allow_extra_text = options.delete(:allow_extra_text)
  @lexer = lexer_class.new(str, line, offset, options)
  @stop_at = nil
end

Constructor Details

#initialize(str, line, offset, options = {}) ⇒ Parser

Returns a new instance of Parser

Parameters:

  • str (String, StringScanner) —

    The source text to parse

  • line (Integer) —

    The line on which the SassScript appears. Used for error reporting and sourcemap building

  • offset (Integer) —

    The character (not byte) offset where the script starts in the line. Used for error reporting and sourcemap building

  • options ({Symbol => Object}) (defaults to: {}) —

    An options hash; see the Sass options documentation. This supports an additional `:allow_extra_text` option that controls whether the parser throws an error when extra text is encountered after the parsed construct.



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# File '.ruby-sass/lib/sass/script/parser.rb', line 32

def initialize(str, line, offset, options = {})
  @options = options
  @allow_extra_text = options.delete(:allow_extra_text)
  @lexer = lexer_class.new(str, line, offset, options)
  @stop_at = nil
end

Class Method Details

.associative?(op) ⇒ Boolean

Returns whether or not the given operation is associative.

Returns:

  • (Boolean) 


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# File '.ruby-sass/lib/sass/script/parser.rb', line 257

def associative?(op)
  ASSOCIATIVE.include?(op)
end

.parse(str, line, offset, filename = nil) ⇒ Script::Tree::Node

Parses a SassScript expression.

Returns:

See Also:



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# File '.ruby-sass/lib/sass/script/parser.rb', line 227

def self.parse(*args)
  new(*args).parse
end

.precedence_of(op) ⇒ Object

Returns an integer representing the precedence of the given operator. A lower integer indicates a looser binding.



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# File '.ruby-sass/lib/sass/script/parser.rb', line 247

def precedence_of(op)
  PRECEDENCE.each_with_index do |e, i|
    return i if Array(e).include?(op)
  end
  raise "[BUG] Unknown operator #{op.inspect}"
end

Instance Method Details

#line ⇒ Integer

The line number of the parser's current position.

Returns:

  • (Integer) 


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# File '.ruby-sass/lib/sass/script/parser.rb', line 11

def line
  @lexer.line
end

#offset ⇒ Integer

The column number of the parser's current position.

Returns:

  • (Integer) 


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# File '.ruby-sass/lib/sass/script/parser.rb', line 18

def offset
  @lexer.offset
end

#parse ⇒ Script::Tree::Node

Parses a SassScript expression.

Returns:

Raises:



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# File '.ruby-sass/lib/sass/script/parser.rb', line 67

def parse
  expr = assert_expr :expr
  assert_done
  expr.options = @options
  check_for_interpolation expr
  expr
rescue Sass::SyntaxError => e
  e.modify_backtrace :line => @lexer.line, :filename => @options[:filename]
  raise e
end

#parse_function_definition_arglist ⇒ (Array<Script::Tree::Node>, Script::Tree::Node)

Parses the argument list for a function definition.

Returns:

Raises:



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# File '.ruby-sass/lib/sass/script/parser.rb', line 174

def parse_function_definition_arglist
  args, splat = defn_arglist!(true)
  assert_done

  args.each do |k, v|
    check_for_interpolation k
    k.options = @options

    if v
      check_for_interpolation v
      v.options = @options
    end
  end

  if splat
    check_for_interpolation splat
    splat.options = @options
  end

  return args, splat
rescue Sass::SyntaxError => e
  e.modify_backtrace :line => @lexer.line, :filename => @options[:filename]
  raise e
end

#parse_interpolated(warn_for_color = false) ⇒ Script::Tree::Node

Parses a SassScript expression within an interpolated segment (`#{}`). This means that it stops when it comes across an unmatched `}`, which signals the end of an interpolated segment, it returns rather than throwing an error.

Parameters:

  • warn_for_color (Boolean) (defaults to: false) —

    Whether raw color values passed to interoplation should cause a warning.

Returns:

Raises:



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# File '.ruby-sass/lib/sass/script/parser.rb', line 48

def parse_interpolated(warn_for_color = false)
  # Start two characters back to compensate for #{
  start_pos = Sass::Source::Position.new(line, offset - 2)
  expr = assert_expr :expr
  assert_tok :end_interpolation
  expr = Sass::Script::Tree::Interpolation.new(
    nil, expr, nil, false, false, :warn_for_color => warn_for_color)
  check_for_interpolation expr
  expr.options = @options
  node(expr, start_pos)
rescue Sass::SyntaxError => e
  e.modify_backtrace :line => @lexer.line, :filename => @options[:filename]
  raise e
end

#parse_mixin_definition_arglist ⇒ (Array<Script::Tree::Node>, Script::Tree::Node)

Parses the argument list for a mixin definition.

Returns:

Raises:



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# File '.ruby-sass/lib/sass/script/parser.rb', line 144

def parse_mixin_definition_arglist
  args, splat = defn_arglist!(false)
  assert_done

  args.each do |k, v|
    check_for_interpolation k
    k.options = @options

    if v
      check_for_interpolation v
      v.options = @options
    end
  end

  if splat
    check_for_interpolation splat
    splat.options = @options
  end

  return args, splat
rescue Sass::SyntaxError => e
  e.modify_backtrace :line => @lexer.line, :filename => @options[:filename]
  raise e
end

#parse_mixin_include_arglist ⇒ (Array<Script::Tree::Node>, {String => Script::Tree::Node}, Script::Tree::Node, Script::Tree::Node)

Parses the argument list for a mixin include.

The root nodes of the positional arguments, keyword arguments, and
splat argument(s). Keyword arguments are in a hash from names to values.

Returns:

Raises:



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# File '.ruby-sass/lib/sass/script/parser.rb', line 105

def parse_mixin_include_arglist
  args, keywords = [], {}
  if try_tok(:lparen)
    args, keywords, splat, kwarg_splat = mixin_arglist
    assert_tok(:rparen)
  end
  assert_done

  args.each do |a|
    check_for_interpolation a
    a.options = @options
  end

  keywords.each do |_, v|
    check_for_interpolation v
    v.options = @options
  end

  if splat
    check_for_interpolation splat
    splat.options = @options
  end

  if kwarg_splat
    check_for_interpolation kwarg_splat
    kwarg_splat.options = @options
  end

  return args, keywords, splat, kwarg_splat
rescue Sass::SyntaxError => e
  e.modify_backtrace :line => @lexer.line, :filename => @options[:filename]
  raise e
end

#parse_string ⇒ Script::Tree::Node

Parse a single string value, possibly containing interpolation. Doesn't assert that the scanner is finished after parsing.

Returns:

Raises:



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# File '.ruby-sass/lib/sass/script/parser.rb', line 204

def parse_string
  unless (peek = @lexer.peek) &&
      (peek.type == :string ||
      (peek.type == :funcall && peek.value.downcase == 'url'))
    lexer.expected!("string")
  end

  expr = assert_expr :funcall
  check_for_interpolation expr
  expr.options = @options
  @lexer.unpeek!
  expr
rescue Sass::SyntaxError => e
  e.modify_backtrace :line => @lexer.line, :filename => @options[:filename]
  raise e
end

#parse_until(tokens) ⇒ Script::Tree::Node

Parses a SassScript expression, ending it when it encounters one of the given identifier tokens.

Parameters:

  • tokens (#include?(String)) —

    A set of strings that delimit the expression.

Returns:

Raises:



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# File '.ruby-sass/lib/sass/script/parser.rb', line 84

def parse_until(tokens)
  @stop_at = tokens
  expr = assert_expr :expr
  assert_done
  expr.options = @options
  check_for_interpolation expr
  expr
rescue Sass::SyntaxError => e
  e.modify_backtrace :line => @lexer.line, :filename => @options[:filename]
  raise e
end