https://explainshell.com/ and http://showthedocs.com/ are a thing of beauty. Why don't we have something like that integrated in our IDEs/REPLs/terminal? Both are interactive — go on, take a non-trivial shell / SQL command from your history and plug it there. I'm not sure I've seen that level of doc integration in any language env, yet an interpreter/compiler doing the actual parsing and name resolution should be well positioned to offer it, no?