Incidentally, a more concise way of doing this would be: (define target (build-path "tarzan")) ; convert to path only once (for/or ([item (in-directory "/tmp/test")]) ; or whatever directory you want to start in (equal? target (file-name-from-path item)))
On Sat, May 8, 2021 at 3:50 AM Utkarsh Singh <utkarsh190...@gmail.com> wrote: > Hi, > > First of all I would like to thank Racket community for creating and > maintaining top quality documentation at https://docs.racket-lang.org/ > and even providing a local copy for it. > > Currently I am having some difficulties in understanding this letrec > example from Racket Guide docs > ( > https://docs.racket-lang.org/guide/let.html#%28part._.Recursive_.Binding__letrec%29 > ): > > (letrec ([tarzan-near-top-of-tree? > (lambda (name path depth) > (or (equal? name "tarzan") > (and (directory-exists? path) > (tarzan-in-directory? path depth))))] > [tarzan-in-directory? > (lambda (dir depth) > (cond > [(zero? depth) #f] > [else > (ormap > (λ (elem) > (tarzan-near-top-of-tree? (path-element->string elem) > (build-path dir elem) > (- depth 1))) > (directory-list dir))]))]) > (tarzan-near-top-of-tree? "tmp" > (find-system-path 'temp-dir) > 4)) > > Problem: > I having some problem on how recursion is working here and what is the > problem we are solving here. Are we finding a file with (name? > "tarzan") or something else? > > -- > Utkarsh Singh > http://utkarshsingh.xyz > > -- > 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/87h7jdslzh.fsf%40gmail.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/CAE8gKodbqAe6DB1rBKBckDWST6f75OV4_35-dcceR7neNfHuaA%40mail.gmail.com.
