Question

Note: this is NOT about concurrency. This is about the thread macro.

I know that -> puts the object at the 2nd position and ->> puts the argument at the last position.

Now, I’m curious, much like the short hand notation of #( ... % ) for functions, is there a short hand notation for threads that lets me place the argument at arbitrary location?

The goal would be that instead of having a fixed location for the thread to run through … I can write arbitrary forms, and insert %% at special places, and the %% is where the thread gets inserted.

Thanks!

Answer 1

The ‘diamond wand’ from Swiss Arrows library would do what you’re asking for:

(-<> 0
 (* <> 5)
 (vector 1 2 <> 3 4))
; => [1 2 0 3 4]

That said, it isn’t something you end up needing often (or ever in my Clojure experience)