class Sass::Script::Tree::Operation - sass-3.4.14 Documentation

# class Sass::Script::Tree::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 [Sass::Script::Tree::Node] The parse-tree node

    for the right-hand side of the operator

@param operand2 [Sass::Script::Tree::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 {Sass::Script::Lexer::OPERATORS}

Calls superclass method

    # File lib/sass/script/tree/operation.rb, line 15
    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::Tree::Node#children

    # File lib/sass/script/tree/operation.rb, line 44
    def children
      [@operand1, @operand2]
    end

deep_copy() click to toggle source

@see Sass::Script::Tree::Node#deep_copy

    # File lib/sass/script/tree/operation.rb, line 49
    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/tree/operation.rb, line 23
    def inspect
      "(#{@operator.inspect} #{@operand1.inspect} #{@operand2.inspect})"
    end

to_sass(opts = {}) click to toggle source

@see Sass::Script::Tree::Node#to_sass

    # File lib/sass/script/tree/operation.rb, line 28
    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; " #{Sass::Script::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 [Sass::Script::Value] 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/tree/operation.rb, line 63
        def _perform(environment)
          value1 = @operand1.perform(environment)

          # Special-case :and and :or to support short-circuiting.
          if @operator == :and
            return value1.to_bool ? @operand2.perform(environment) : value1
          elsif @operator == :or
            return value1.to_bool ? value1 : @operand2.perform(environment)
          end

          value2 = @operand2.perform(environment)

          if (value1.is_a?(Sass::Script::Value::Null) || value2.is_a?(Sass::Script::Value::Null)) &&
              @operator != :eq && @operator != :neq
            raise Sass::SyntaxError.new(
              "Invalid null operation: \"#{value1.inspect} #{@operator} #{value2.inspect}\".")
          end

          begin
            result = opts(value1.send(@operator, value2))
          rescue NoMethodError => e
            raise e unless e.name.to_s == @operator.to_s
            raise Sass::SyntaxError.new("Undefined operation: \"#{value1} #{@operator} #{value2}\".")
          end

          if (@operator == :eq || @operator == :neq) && value1.is_a?(Sass::Script::Value::Number) &&
             value2.is_a?(Sass::Script::Value::Number) && value1.unitless? != value2.unitless? &&
             result == (if @operator == :eq
                          Sass::Script::Value::Bool::TRUE
                        else
                          Sass::Script::Value::Bool::FALSE
                        end)

            operation = "#{value1} #{@operator == :eq ? '==' : '!='} #{value2}"
            future_value = @operator == :neq
            Sass::Util.sass_warn <<WARNING
    DEPRECATION WARNING on line #{line}#{" of #{filename}" if filename}:
    The result of `#{operation}` will be `#{future_value}` in future releases of Sass.
    Unitless numbers will no longer be equal to the same numbers with units.
    WARNING
          end

          result
        end

### Private Instance Methods

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

    # File lib/sass/script/tree/operation.rb, line 110
    def operand_to_sass(op, side, opts)
      return "(#{op.to_sass(opts)})" if op.is_a?(Sass::Script::Tree::ListLiteral)
      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