symfony/symfony-docs — pull request #3771 by raulfraile (2014-04-07 14:46:58+00:00)
Title: Fix function example in expression language component

The is_string check needs to be part of the runtime code, not of the compilation code, because it needs to check that the argument is a string, not the compiled code to access it (which is always a string as it is source code. cc @stof