class Sass::Script::Tree::Operation

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

def children
  [@operand1, @operand2]
end

def deep_copy
  node = dup
  node.instance_variable_set('@operand1', @operand1.deep_copy)
  node.instance_variable_set('@operand2', @operand2.deep_copy)
  node
end

def initialize(operand1, operand2, operator)
  @operand1 = operand1
  @operand2 = operand2
  @operator = operator
  super()
end

def inspect
  "(#{@operator.inspect} #{@operand1.inspect} #{@operand2.inspect})"
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

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

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)
operation `#{value1} #{@operator} #{value2}` is deprecated and will be an error in future versions.
ider using Sass's color functions instead.
s://sass-lang.com/documentation/Sass/Script/Functions.html#other_color_functions
ING
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)
result of `#{operation}` will be `#{future_value}` in future releases of Sass.
less numbers will no longer be equal to the same numbers with units.
ING
end