forked from sass/sass
/
operation.rb
90 lines (79 loc) · 2.83 KB
/
operation.rb
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require 'set'
require 'sass/script/string'
require 'sass/script/number'
require 'sass/script/color'
require 'sass/script/functions'
require 'sass/script/unary_operation'
require 'sass/script/interpolation'
require 'sass/script/string_interpolation'
module Sass::Script
# A SassScript parse node representing a binary operation,
# such as `$a + $b` or `"foo" + 1`.
class Operation < Node
attr_reader :operand1
attr_reader :operand2
attr_reader :operator
# @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}
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 = {})
pred = Sass::Script::Parser.precedence_of(@operator)
o1 = operand_to_sass pred, @operand1, opts
o2 = operand_to_sass pred, @operand2, opts
sep =
case @operator
when :comma; ", "
when :concat; " "
else; " #{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
protected
# 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
def _perform(environment)
literal1 = @operand1.perform(environment)
literal2 = @operand2.perform(environment)
if @operator == :concat && context == :equals
literal1 = Sass::Script::String.new(literal1.value) if literal1.is_a?(Sass::Script::String)
literal2 = Sass::Script::String.new(literal2.value) if literal2.is_a?(Sass::Script::String)
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
def operand_to_sass(pred, op, opts = {})
return "(#{op.to_sass(opts)})" if op.is_a?(Operation) &&
Sass::Script::Parser.precedence_of(op.operator) < pred
op.to_sass(opts)
end
end
end