Arc Forumnew | comments | leaders | submitlogin
2 points by Pauan 4780 days ago | link | parent

"I like it if and only if this works:"

That doesn't, but this does:

  (let (a . b) '(1 2 3)
    ...)
The reason is because racket-mlist->list expects a proper list. I can fix that easily.

Update: I fixed racket-mlist->list, but Racket's apply absolutely positively requires a proper list, so it looks like I can't use nested lambdas if I want to fix that: I'll have to use a Racket let*

---

"I almost expect Racket to copy a mutable argument list into an immutable one for use inside the lambda"

It's true, it does copy the list, so that returns nil. I wonder if I can work around that...

---

"One reason it's on my mind is the Racket 5.2 changelog"

I'm not using Racket 5.2. And even if I were, the reason for the speed tests was to see how it would perform within the (fn ...) expansion, where it does indeed overwrite an already-existing variable. (Though I could change it to use a gensym...)