Hello, Arne Babenhauserheide <arne_...@web.de> writes:
> Hello Hans-Werner Roitzsch, > > It looks like you’re mixing up two concepts: the fac creates a module > and loads the fact which is not a module, so basically main and choose > live in another namespace than fact (define-module starts a new > namespace). > > And it seems that this is indeed a bug in the documentation, because > https://www.gnu.org/software/guile/manual/html_node/Scripting-Examples.html#Scripting-Examples > jumps to defining fac as a module but does not at the same time define > and import fact as a module, too. > > Hans-Werner Roitzsch <hwroitz...@posteo.net> writes: >> I have the file `modules.scm` with the following code: >> >> ----8<----start-of-code---->8---- >> #!/usr/bin/env sh >> exec guile -l fact.scm -e '(@ (my-module) main)' -s "$0" "$@" >> !# >> >> ;; Explanation: >> ;; -e (my-module) >> ;; If run as a script run the `my-module` module's `main`. >> ;; (Use `@@` to reference not exported procedures.) >> ;; -s >> ;; Run the script. >> >> (define-module (my-module) >> #:export (main)) > > At this point you need > > (use-modules (fact)) > >> ;; Create a module named `fac`. >> ;; Export the `main` procedure as part of `fac`. >> >> (define (n-choose-k n k) >> (/ (fact n) >> (* (fact k) >> (fact (- n k))))) >> >> (define (main args) >> (let ((n (string->number (cadr args))) >> (k (string->number (caddr args)))) >> (display (n-choose-k n k)) >> (newline))) >> ----8<----end-of-code---->8---- >> >> And I have the following `fact.scm`: >> >> ----8<----start-of-code---->8---- >> #!/usr/local/bin/guile \ >> -e main -s >> !# >> >> ;; How to run this program? >> ;; Example: >> ;; guile -e main -s factorial-script.scm 50 >> ;; Explanation: >> ;; -e specifies the procedure to run >> ;; -s specifies to run this as a script >> ;; 50 is the number we take as input to the script > > To be usable as module, this needs to be defined as module: > > (define-module (fact) > #:export (fact)) > >> (define (fact n) >> (if (zero? n) 1 >> (* n (fact (- n 1))))) >> >> (define (main args) >> (display (fact (string->number (cadr args)))) >> (newline)) >> ----8<----end-of-code---->8---- > … >> chmod +x modules.scm >> ./modules.scm 10 3 > > Does it work with the added module definition and import? Thank you for the above explanations. I got confused by the this in the documentation as well. Trying the above suggestions, I still have a problem. I have the following two files: fact: --8<---------------cut here---------------start------------->8--- #!/run/current-system/profile/bin/guile \ -e main -s !# (define-module (fact) #:export (fact)) (define (fact n) (if (zero? n) 1 (* n (fact (- n 1))))) (define (main args) (display (fact (string->number (cadr args)))) (newline)) --8<---------------cut here---------------end--------------->8--- fac: --8<---------------cut here---------------start------------->8--- #!/run/current-system/profile/bin/guile \ -e (@@ (fac) main) -s !# (define-module (fac) #:export (main)) (use-modules (fact)) (define (choose n m) (/ (fact m) (* (fact (- m n)) (fact n)))) (define (main args) (let ((n (string->number (cadr args))) (m (string->number (caddr args)))) (display (choose n m)) (newline))) --8<---------------cut here---------------end--------------->8--- But with Guile 3.0.8, this gives me: --8<---------------cut here---------------start------------->8--- ./fac 5 20 ice-9/read.scm:126:4: In procedure lp: #<unknown port>:1:4: unexpected end of input while searching for: ) --8<---------------cut here---------------end--------------->8--- Which I don't understand. -- Thanks, Maxim
