Addition of a compact_map/2 function to the Enum module

[dimitarvp]

@sodapopcan

EDIT: I re-read the thread and had missed @dimitarvp’s message re: filter_map which I believe Elixir actually used to have?

And I was wondering why I can’t quickly find filter_map… It was last directly accessible in the docs all the way back in Elixir 1.4.5, woah.

@gregvaughn

The main piece to understand are filters in for comprehensions. If you have a clause that is not a generator, it’s a filter. If it evaluates to falsy, then the do block is not executed and the next iteration begins.

I understand the liking of the for comprehension and used it a lot but the whole truthy / falsy thing just rings my alarms as I am an other side of the spectrum and I want explicitness all the way to the point of ju-u-ust before it becomes unwieldy and annoying. To me the truthy / falsy semantics will be never welcome but oh well. Just adding one more anecdote because arguing for/against it is fruitless; it’s just a preference in the end, and it is clear that the core team is not on my side in this instance. I’ll just never ever approve of the if value ... thing.