i just understood the scheme :-) scheme@(guile-user)> (list-transduce (compose (tfilter (λ (x) x)) (tdelete-duplicates)) rcons (list 1 2 #f 3 3 4)) $12 = (1 2 3 4)
sorry... On Thu, Dec 22, 2022 at 3:33 PM Damien Mattei <damien.mat...@gmail.com> wrote: > hello, > just trying transducers before using it, i try to understand. > what is wrong with that: > scheme@(guile-user)> (list-transduce (tfilter (λ (x) x)) > (tdelete-duplicates) (list 1 2 #f 3 3 4)) > ice-9/boot-9.scm:1685:16: In procedure raise-exception: > Wrong number of arguments to #<procedure 10786aa60 at > srfi/srfi-171.scm:338:2 (reducer)> > > Entering a new prompt. Type `,bt' for a backtrace or `,q' to continue. > > Regards, > Damien > > On Wed, Dec 21, 2022 at 11:01 AM Linus Björnstam < > linus.bjorns...@veryfast.biz> wrote: > >> As the author of both the SRFI and the guile code I am very happy you >> like it. I don't have a computer at the moment, but I looked through the >> code and it looked great. >> >> All additions should have been included in the original SRFI :) >> >> one comment: your code uses define-public, which the rest of SRFI-171 >> code does not. >> >> I am not in any position to sign code off for inclusion in guile proper, >> but if the define-public thing is fixed it very much has my blessing. >> >> Best regards >> Linus Björnstam >> >> On Wed, 21 Dec 2022, at 01:48, Colin Woodbury wrote: >> > Happy holidays everyone, I hope everything is going well for you. >> > >> > Since discovering SRFI-171 (Transducers) I have fallen in love with it. >> > Transducers let me "talk the way I want to talk" while knowing that I'm >> > being efficient underneath w.r.t. to iteration and allocation. In using >> > Guile's implementation, I noticed a few common idioms missing that are >> > otherwise present in other languages, so I've added them in a series of >> > patches. I've been using these often for a number of weeks without >> > issue, but of course have added unit tests as well. >> > >> > The full details are in the commit messages, but here are the main >> highlights: >> > >> > * rfold: The fundamental reducer. This allows the user to turn any >> > two-arg function into a valid reducer, so that they don't need to worry >> > about hand-writing reducers via case-lambda. >> > * rfind: Yields the first item in the transduction that matches some >> > predicate. Nice for locating some specific value from a potentially >> > large data source (e.g. a port). >> > * twindow: Like tsegment, but yields overlapping slices into the data. >> > Cheers, and have a great holiday. >> > >> > Colin >> > >> > Attachments: >> > * 0001-srfi-171-add-twindow-and-various-reducers.patch >> > * 0002-doc-add-new-SRFI-171-reducers-to-the-manual.patch >> > * 0003-srfi-171-add-unit-tests-for-new-functions.patch >> >>
