Ahh ok, thank you that makes sense. I didn't know about PLT_LINKLET_SHOW_CP0 before that is a nice look behind the scene.
sorawe...@gmail.com schrieb am Sonntag, 21. März 2021 um 19:47:03 UTC+1: > That’s not the job of the macro expander. And the Racket optimizer does > reduce (if '#t (#%app not '#f) '#f) — in fact to #t. > > If you use Racket CS, try running: > > PLT_LINKLET_SHOW_CP0=1 racket file.rkt > > where file.rkt is > > #lang racket > (displayln (if #t (not #f) #f)) > > Here’s the optimized program: > > ;; cp0 --------------------- > (lambda (instance-variable-reference .get-syntax-literal!1 > .set-transformer!2 displayln3 print-values4) > (call-with-module-prompt > (lambda () > (#%call-with-values > (lambda () (displayln3 #t)) > print-values4))) > (#2%void)) > > > On Mon, Mar 22, 2021 at 1:28 AM schle...@gmail.com <schle...@gmail.com> > wrote: > >> The [WordCount] thread caused me to play around with the solutions to see >> whether I could see anything else that can be tweaked, I tried a few things >> but they didn't improve performance, but it was fun anyway. >> >> Then I though I could try the macro stepper and look at the expansion of >> [crowdsourced]. >> I disabled macro hiding and stepped to the end. >> There I saw if statements with a condition that is `(quote #t)` with a >> little lock symbol before it. >> >> I would like to understand why those terms aren't reduced further. >> Are they placeholders and are replaced and resolved at a later time? >> >> terms copied (without the lock symbol) from the macro stepper >> (if (if '#t (#%app not '#f) '#f) >> (#%app for-loop (#%app unsafe-fx+ '1 pos)) >> (#%app values)) >> >> From a naive standpoint I would expect it to be simplified: >> (if '#t (#%app not '#f) '#f) -> (#%app not '#f) >> >> (if (#%app not '#f) >> (#%app for-loop (#%app unsafe-fx+ '1 pos)) >> (#%app values)) >> >> So expressed another way: why isn't the if with boolean literal as >> condition reduced to the corresponding branch? Or does this happen, just >> isn't shown in the macro stepper? >> What am I misunderstanding here? >> >> If there aren't simplifications like that, what is preventing them or >> making them not worthwhile? >> >> >> [WordCount] >> https://groups.google.com/g/racket-users/c/lGA60P6jboY/m/2ZLDAunBBgAJ >> [crowdsourced] >> https://gist.github.com/Bogdanp/b9256e1a91de9083830cb616b3659ff8 >> >> -- >> You received this message because you are subscribed to the Google Groups >> "Racket Users" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to racket-users...@googlegroups.com. >> To view this discussion on the web visit >> https://groups.google.com/d/msgid/racket-users/fce863fe-85d7-44a6-a2ba-5778df40e6bfn%40googlegroups.com >> >> <https://groups.google.com/d/msgid/racket-users/fce863fe-85d7-44a6-a2ba-5778df40e6bfn%40googlegroups.com?utm_medium=email&utm_source=footer> >> . >> > -- You received this message because you are subscribed to the Google Groups "Racket Users" group. To unsubscribe from this group and stop receiving emails from it, send an email to racket-users+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/racket-users/cd4f9860-e57d-4ce2-bef8-6598a28ddfafn%40googlegroups.com.
