class Sass::Script::Operation - sass-3.2.19 Documentation

# class Sass::Script::Operation

A SassScript parse node representing a binary operation, such as `$a + $b` or `“foo” + 1`.

### Attributes

operand1[R]
operand2[R]
operator[R]

### Public Class Methods

new(operand1, operand2, operator) click to toggle source

@param operand1 [Script::Node] The parse-tree node

    for the right-hand side of the operator

@param operand2 [Script::Node] The parse-tree node

    for the left-hand side of the operator

@param operator [Symbol] The operator to perform.

    This should be one of the binary operator names in {Lexer::OPERATORS}

Calls superclass method

    # File lib/sass/script/operation.rb, line 24
    def initialize(operand1, operand2, operator)
      @operand1 = operand1
      @operand2 = operand2
      @operator = operator
      super()
    end

### Public Instance Methods

children() click to toggle source

Returns the operands for this operation.

@return [Array<Node>] @see Sass::Script::Node#children

    # File lib/sass/script/operation.rb, line 53
    def children
      [@operand1, @operand2]
    end

deep_copy() click to toggle source

@see Sass::Script::Node#deep_copy

    # File lib/sass/script/operation.rb, line 58
    def deep_copy
      node = dup
      node.instance_variable_set('@operand1', @operand1.deep_copy)
      node.instance_variable_set('@operand2', @operand2.deep_copy)
      node
    end

inspect() click to toggle source

@return [String] A human-readable s-expression representation of the operation

    # File lib/sass/script/operation.rb, line 32
    def inspect
      "(#{@operator.inspect} #{@operand1.inspect} #{@operand2.inspect})"
    end

to_sass(opts = {}) click to toggle source

@see Sass::Script::Node#to_sass

    # File lib/sass/script/operation.rb, line 37
    def to_sass(opts = {})
      o1 = operand_to_sass @operand1, :left, opts
      o2 = operand_to_sass @operand2, :right, opts
      sep =
        case @operator
        when :comma; ", "
        when :space; " "
        else; " #{Lexer::OPERATORS_REVERSE[@operator]} "
        end
      "#{o1}#{sep}#{o2}"
    end

### Protected Instance Methods

_perform(environment) click to toggle source

Evaluates the operation.

@param environment [Sass::Environment] The environment in which to evaluate the SassScript @return [Literal] The SassScript object that is the value of the operation @raise [Sass::SyntaxError] if the operation is undefined for the operands

    # File lib/sass/script/operation.rb, line 72
    def _perform(environment)
      literal1 = @operand1.perform(environment)

      # Special-case :and and :or to support short-circuiting.
      if @operator == :and
        return literal1.to_bool ? @operand2.perform(environment) : literal1
      elsif @operator == :or
        return literal1.to_bool ? literal1 : @operand2.perform(environment)
      end

      literal2 = @operand2.perform(environment)

      if (literal1.is_a?(Null) || literal2.is_a?(Null)) && @operator != :eq && @operator != :neq
        raise Sass::SyntaxError.new("Invalid null operation: \"#{literal1.inspect} #{@operator} #{literal2.inspect}\".")
      end

      begin
        opts(literal1.send(@operator, literal2))
      rescue NoMethodError => e
        raise e unless e.name.to_s == @operator.to_s
        raise Sass::SyntaxError.new("Undefined operation: \"#{literal1} #{@operator} #{literal2}\".")
      end
    end

### Private Instance Methods

operand_to_sass(op, side, opts) click to toggle source

    # File lib/sass/script/operation.rb, line 98
    def operand_to_sass(op, side, opts)
      return "(#{op.to_sass(opts)})" if op.is_a?(List)
      return op.to_sass(opts) unless op.is_a?(Operation)

      pred = Sass::Script::Parser.precedence_of(@operator)
      sub_pred = Sass::Script::Parser.precedence_of(op.operator)
      assoc = Sass::Script::Parser.associative?(@operator)
      return "(#{op.to_sass(opts)})" if sub_pred < pred ||
        (side == :right && sub_pred == pred && !assoc)
      op.to_sass(opts)
    end