I wrote two set-adds? Ugh, I didn't mean to. That code wouldn't even work due to arity mismatch. (set-add res (let ([v v]) v)) is more likely. -Ian ----- Original Message ----- From: Sam Tobin-Hochstadt <sa...@ccs.neu.edu> To: J. Ian Johnson <i...@ccs.neu.edu> Cc: users <users@racket-lang.org> Sent: Thu, 4 Oct 2012 19:46:36 -0400 (EDT) Subject: Re: [racket] Vast performance differences with minute syntactic differences
On Thu, Oct 4, 2012 at 7:01 PM, J. Ian Johnson <i...@ccs.neu.edu> wrote: > > By almost exactly I mean > (let () (set-add res v)) > > versus > > (let ([res res]) > (set-add (let ([v v]) > (set-add res (let () v))))) These seem importantly different, in that: (set-add v (set-add res v)) and (set-add res v) are totally different values, and the former only works if both `v` and `res` are sets. If you want to determine the behavior of the compiler, which is what matters for differences like extra `let` bindings, 'raco decompile' is the best tool. -- sam th sa...@ccs.neu.edu ____________________ Racket Users list: http://lists.racket-lang.org/users
