Hi Sirgazil, sirgazil <sirga...@zoho.com> writes:
> Hi, > > When using "guile-config" for declaring my CLIs I've noticed that if I > define an argument as non-optional for a command, then trying to > display the --help of that command fails. You are correct. This issue arises because guile-config uses (ice-9 getopt-long) internally to parse the command line arguments and handle all the usual gnu cli argument niceties. However this causes a chicken and egg problem: to execute help when the --help flag is provide we need to have parsed the cli options. But getopt-long throws an error whilst parsing the cli options as soon as it detects a mandatory argument is missing. This is not ideal. The solution would probably be have to be to re-implement cli argument parsing outside of getopt-long, or to patch getopt-long to not throw on validation-error but to return an error-structure, which includes the parsed cli args, but also any problems it encountered during validation. Dunno which is better at this point, but I'll log your report and my thoughts as a bug against guile-config for now. Of course, patches implementing either solution, welcome! :-) Best wishes, Alex > > Consider the following script which displays "What yummy apple!" when it's > run like "$ eat apple": > > > #+BEGIN_SRC scheme > (use-modules (config) > (config api) > (ice-9 format) > (ice-9 match)) > > > ;;; CONSTANTS > ;;; ========= > > (define FRUITS > (list "apple" "banana" "kiwi" "mango")) > > > > ;;; VALIDATORS > ;;; ========== > > (define (fruit? fruit) > (member fruit FRUITS)) > > > > ;;; ARGUMENTS AND OPTIONS > ;;; ===================== > > (define fruit > (argument (name 'fruit) > (synopsis "The name of a fruit.") > (example "apple") > (optional? #false) > (test fruit?))) > > > > ;;; CLI SPECIFICATION > ;;; ================= > > (define spec > (configuration > (name 'eat) > (synopsis "Eat imaginary fruits.") > (version "1.0") > (arguments (list fruit)))) > > > > ;;; CLI DISPATCHER > ;;; ============== > > (define (dispatcher command spec) > #| Execute the appropriate procedure for the given COMMAND if it is > part of the given command-line interface specification. > > COMMAND (list of strings) > A list of strings that represent a command-line instruction passed > to the program (see the Guile command-line procedure). > > SPEC (Configuration) > A <configuration> record as specified by the guile-config library > specifying the command-line interface of the program. > > RESULT > Execute the COMMAND or display help information if the COMMAND is > not recognized. |# > (let* ((options (getopt-config-auto command spec)) > (fruit (option-ref options '(fruit)))) > (catch 'match-error > (lambda () > (match (full-command options) > ((_) (format #true "What yummy ~a!!~%" fruit)))) > > (lambda (. args) > (begin (display "ERROR: Command not found.") > (newline) (newline) > (emit-help options)))))) > > > > ;;; RUN > ;;; === > > (dispatcher (command-line) spec) > > #+END_SRC > > > Now, when I try to display the help information of the "eat" command, I get > this message: > > > #+BEGIN_EXAMPLE > $ eat --help > error: eat: argument must be specified: fruit > Usage: eat > > Options: > #+END_EXAMPLE > > > Is this a bug or am I doing something wrong? > > > --- > https://sirgazil.bitbucket.io/
