# File lib/sass/script/interpolation.rb, line 59 def _perform(environment) res = "" res << @before.perform(environment).to_s if @before res << " " if @before && @whitespace_before val = @mid.perform(environment) res << (val.is_a?(Sass::Script::String) ? val.value : val.to_s) res << " " if @after && @whitespace_after res << @after.perform(environment).to_s if @after opts(Sass::Script::String.new(res)) end