Here are several variants of the code: https://gist.github.com/d6fbe3757c462d5b4d1d9393b72f9ab9
The enabled version is about the fastest I can get without using `unsafe` (which the rules said not to do). It's possible to optimize a tiny bit more by avoiding sorting, but only a few milliseconds -- it would be more significant if there were more different words. Switching to bytes works correctly for the given task, but wouldn't always work in the case of general UTF8 input. But those versions appeared not be faster for me. Also, writing my own string-downcase didn't help. And using a big buffer and doing my own newline splitting didn't help either. The version using just a regexp matching on a port (suggested by Robby) turned out not to be faster either, so my suspicion is that the original slowness is just using regexps for splitting words. Sam On Thu, Mar 18, 2021 at 11:28 AM Sam Tobin-Hochstadt <sa...@cs.indiana.edu> wrote: > > Here's a somewhat-optimized version of the code: > > #lang racket/base > (require racket/string racket/vector racket/port) > > (define h (make-hash)) > > (time > (for* ([l (in-lines)] > [w (in-list (string-split l))] > [w* (in-value (string-downcase w))]) > (hash-update! h w* add1 0))) > > (define v > (time > (for/vector #:length (hash-count h) > ([(k v) (in-hash h)]) > (cons k v)))) > (time (vector-sort! v > #:key cdr)) > (define p (current-output-port) #;(open-output-nowhere)) > (time > (for ([pair (in-vector v)]) > (write-string (car pair) p) > (write-string (number->string (cdr pair)) p) > (newline p))) > > It's much more imperative, but also pretty nice and compact. The > `printf` optimization is significant for that portion of the program, > but that isn't much of the running time. The overall running time for > 10 copies of the KJV is about 9 seconds on my laptop. > > I think the remaining difference between Racket and other languages is > likely the `string-split` and `string-downcase` functions, plus the > relatively-inefficient string representation that Racket uses. > > Sam > > > On Thu, Mar 18, 2021 at 10:28 AM Pawel Mosakowski <pa...@mosakowski.net> > wrote: > > > > Hi David, > > > > Yes, the 21 seconds includes the interpreter startup time. I have done a > > simple test to see how long it takes: > > > > $ time racket -e '(displayln "Hello, world")' > > Hello, world > > > > real 0m0.479s > > user 0m0.449s > > sys 0m0.030s > > > > I have also put my code inside a main function and profiled it: > > > > Profiling results > > ----------------- > > Total cpu time observed: 20910ms (out of 20970ms) > > Number of samples taken: 382 (once every 55ms) > > (Hiding functions with self<1.0% and local<2.0%: 1 of 12 hidden) > > > > ============================================================== > > Caller > > Idx Total Self Name+src Local% > > ms(pct) ms(pct) Callee > > ============================================================== > > [1] 20910(100.0%) 0(0.0%) [running body] > > ...word-occurences-profile.rkt":##f > > profile-thunk [2] 100.0% > > -------------------------------------------------------------- > > [running body] [1] 100.0% > > [2] 20910(100.0%) 0(0.0%) profile-thunk > > ...ket/pkgs/profile-lib/main.rkt:9:0 > > run [3] 100.0% > > -------------------------------------------------------------- > > profile-thunk [2] 100.0% > > [3] 20910(100.0%) 0(0.0%) run > > ...share/racket/pkgs/profile-lib/main.rkt:39:2 > > main [4] 100.0% > > -------------------------------------------------------------- > > run [3] 100.0% > > [4] 20910(100.0%) 50(0.2%) main > > ...cket/count-word-occurences-profile.rkt:5:0 > > read-from-stdin-it [5] 98.5% > > ??? [6] 0.2% > > -------------------------------------------------------------- > > main [4] 100.0% > > [5] 20606(98.5%) 11796(56.4%) read-from-stdin-it > > ...-occurences-profile.rkt:19:6 > > internal-split [7] 42.8% > > -------------------------------------------------------------- > > main [4] 100.0% > > [6] 51(0.2%) 0(0.0%) ??? > > ...cket/collects/racket/private/sort.rkt:369:3 > > generic-sort/key [8] 100.0% > > -------------------------------------------------------------- > > read-from-stdin-it [5]100.0% > > [7] 8810(42.1%) 3528(16.9%) internal-split > > ...collects/racket/string.rkt:117:0 > > regexp-split [9] 59.9% > > -------------------------------------------------------------- > > ??? [6] 100.0% > > [8] 51(0.2%) 0(0.0%) generic-sort/key > > .../racket/private/sort.rkt:156:2 > > copying-mergesort [10]100.0% > > -------------------------------------------------------------- > > internal-split [7] 100.0% > > [9] 5282(25.3%) 2810(13.4%) regexp-split > > ...ts/racket/private/string.rkt:338:2 > > loop [11] 46.8% > > -------------------------------------------------------------- > > generic-sort/key [8] 10.0% > > copying-mergesort [10] 90.0% > > [10] 51(0.2%) 51(0.2%) copying-mergesort > > ...racket/private/sort.rkt:129:8 > > copying-mergesort [10] 90.0% > > -------------------------------------------------------------- > > regexp-split [9] 100.0% > > [11] 2471(11.8%) 2471(11.8%) loop > > ...t/collects/racket/private/string.rkt:169:7 > > -------------------------------------------------------------- > > > > Kind regards, > > Pawel > > > > > > On Thursday, March 18, 2021 at 2:09:35 PM UTC david....@gmail.com wrote: > >> > >> Hi Pawel, > >> > >> I'll take a look at the code later, but did that 21 seconds include > >> startup time for the interpreter? > >> > >> On Thu, Mar 18, 2021, 9:24 AM Pawel Mosakowski <pa...@mosakowski.net> > >> wrote: > >>> > >>> Hello, > >>> > >>> I am a Racket beginner and I have come across this article: > >>> > >>> https://benhoyt.com/writings/count-words/ > >>> > >>> This is my attempt at solving the challenge: > >>> > >>> https://pastebin.com/kL16w5Hc > >>> > >>> However when I have benchmarked it, it takes ~21 seconds to run compared > >>> to the Python and Ruby versions which take around 3-4 seconds. > >>> > >>> I understand that both Ruby and Python probably have the string > >>> operations and hash tables implemented in optimized C but is there > >>> anything I can do to improve performance of my program? > >>> > >>> Many thanks for all help and suggestions. > >>> > >>> -- > >>> 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/118c1340-66d1-421d-92a4-6b66c56cb88fn%40googlegroups.com. > > > > -- > > 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/09c58a34-bd2d-49e7-bfbd-d3253c1e6dd1n%40googlegroups.com. -- You received this message because you are subscribed to the Google Groups "Racket Users" group. 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