Is there any sort of zip & unzip functions for lists built into Racket? Or a fairly standard extra package that includes them? I have a particular use for an unzip right now. While I could quite easily write my own function, it’s the sort of thing that I think in practice it is better to use from elsewhere if there’s a ‘standard’ version of it.

@jcoo092 try https://docs.racket-lang.org/file/index.html

Oh, no, I’m not talking about working with zip files - just something akin to e.g. https://msdn.microsoft.com/visualfsharpdocs/conceptual/list.unzip%5b%27t1%2c%27t2%5d-function-%5bfsharp%5d

@jcoo092 zip is (map list xs ys)

It’s in srfi/1 btw.

So are unzip1, …, unzip5

https://docs.racket-lang.org/srfi/srfi-std/srfi-1.html?q=zip#zip

Maybe this too https://docs.racket-lang.org/zippers/index.html

I’d prefer (map first ziped-list) over unzip1 though.

@jcoo092 in general you don’t need zip because map takes multiple list arguments.

Thanks @spdegabrielle, @soegaard2 & @samth :slightly_smiling_face:

Found a series of video lectures based on HtDP. https://www.youtube.com/channel/UC7dEjIUwSxSNcW4PqNRQW8w