Don't think I'm understanding what you mean - composability of what exactly? It's a very Python-like language, so if-blocks behave like they do in Python/C, etc. Suppressing one's output: are you referring to invoking shell commands? Each shell invocation (at the moment) happens in its own session, independent of others, so variable assignments really only matter if you're basically embedding a shell script in RSL as e.g. a multiline string, and then invoking it. But I might be misunderstanding what you mean!