# File lib/sass/script/tree/string_interpolation.rb, line 89 def _perform(environment) res = "" before = @before.perform(environment) res << before.value mid = @mid.perform(environment) res << (mid.is_a?(Sass::Script::Value::String) ? mid.value : mid.to_s(:quote => :none)) res << @after.perform(environment).value opts(Sass::Script::Value::String.new(res, before.type)) end