| module Sass::Script::Tree |
| # A SassScript parse node representing a binary operation, |
| # such as `$a + $b` or `"foo" + 1`. |
| class Operation < Node |
| @@color_arithmetic_deprecation = Sass::Deprecation.new |
| @@unitless_equals_deprecation = Sass::Deprecation.new |
| |
| attr_reader :operand1 |
| attr_reader :operand2 |
| attr_reader :operator |
| |
| # @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} |
| def initialize(operand1, operand2, operator) |
| @operand1 = operand1 |
| @operand2 = operand2 |
| @operator = operator |
| super() |
| end |
| |
| # @return [String] A human-readable s-expression representation of the operation |
| def inspect |
| "(#{@operator.inspect} #{@operand1.inspect} #{@operand2.inspect})" |
| end |
| |
| # @see Node#to_sass |
| 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 |
| |
| # Returns the operands for this operation. |
| # |
| # @return [Array<Node>] |
| # @see Node#children |
| def children |
| [@operand1, @operand2] |
| end |
| |
| # @see Node#deep_copy |
| def deep_copy |
| node = dup |
| node.instance_variable_set('@operand1', @operand1.deep_copy) |
| node.instance_variable_set('@operand2', @operand2.deep_copy) |
| node |
| end |
| |
| protected |
| |
| # 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 |
| 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 |
| |
| warn_for_color_arithmetic(value1, value2) |
| warn_for_unitless_equals(value1, value2, result) |
| |
| result |
| end |
| |
| private |
| |
| def warn_for_color_arithmetic(value1, value2) |
| return unless @operator == :plus || @operator == :times || @operator == :minus || |
| @operator == :div || @operator == :mod |
| |
| if value1.is_a?(Sass::Script::Value::Number) |
| return unless value2.is_a?(Sass::Script::Value::Color) |
| elsif value1.is_a?(Sass::Script::Value::Color) |
| return unless value2.is_a?(Sass::Script::Value::Color) || value2.is_a?(Sass::Script::Value::Number) |
| else |
| return |
| end |
| |
| @@color_arithmetic_deprecation.warn(filename, line, <<WARNING) |
| The operation `#{value1} #{@operator} #{value2}` is deprecated and will be an error in future versions. |
| Consider using Sass's color functions instead. |
| http://sass-lang.com/documentation/Sass/Script/Functions.html#other_color_functions |
| WARNING |
| end |
| |
| def warn_for_unitless_equals(value1, value2, result) |
| return unless @operator == :eq || @operator == :neq |
| return unless value1.is_a?(Sass::Script::Value::Number) |
| return unless value2.is_a?(Sass::Script::Value::Number) |
| return unless value1.unitless? != value2.unitless? |
| return unless result == (if @operator == :eq |
| Sass::Script::Value::Bool::TRUE |
| else |
| Sass::Script::Value::Bool::FALSE |
| end) |
| |
| operation = "#{value1.to_sass} #{@operator == :eq ? '==' : '!='} #{value2.to_sass}" |
| future_value = @operator == :neq |
| @@unitless_equals_deprecation.warn(filename, line, <<WARNING) |
| 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 |
| |
| 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 |
| end |
| end |