When using the "command-line" macro for parsing "raco" commands with
subcommands (e.g., "raco mycommand mysubcommand arg ..."), is there a
better way than the code fragment at the end of this message?
The main problem I have with this code fragment is that "raco mycommand
--help" is not very helpful, because it doesn't list the actual subcommands:
$ raco mcfly --help
raco mcfly [ <option> ... ] [<subcommand>] [<subcommand-arg>] ...
where <option> is one of
--help, -h : Show this help
-- : Do not treat any remaining argument as a switch (at this level)
Multiple single-letter switches can be combined after one `-'; for
example: `-h-' is the same as `-h --'
If the "command-line" macro can't do subcommands better, than I'll
probably use it only for the individual subcommand-specific parses.
I don't want the subcommand to be a ``flag'', although the
"command-line" macro could handle it then.
The code fragment is:
(let-values (((subcommand subcommand-args)
(command-line
#:program (current-program)
#:args ((subcommand #f) . subcommand-arg)
(values subcommand subcommand-arg))))
(parameterize ((current-command-line-arguments
(list->vector subcommand-args)))
(let loop-subcommand ((subcommand subcommand))
(cond ((not subcommand)
(printf "*DEBUG* no subcommand\n")
;; TODO: !!!
)
;; Subcommands:
((equal? subcommand "dev-links")
(printf "*DEBUG* dev-links\n")
(parameterize ((current-subcommand subcommand))
(update-dev-links (command-line
#:program (current-program)
#:once-each
(("--no-server" "--ns")
"Do not use the PLaneT server"
;; TODO: !!!
(void))
#:args directory-tree-to-search
directory-tree-to-search))))
((equal? subcommand "setup-all")
(printf "*DEBUG* setup-all\n")
(parameterize ((current-subcommand subcommand))
;; TODO: !!!
(void)))
((equal? subcommand "setup-package")
(printf "*DEBUG* setup-package\n")
(parameterize ((current-subcommand subcommand))
;; TODO: !!!
(void)))
((equal? subcommand "view")
(printf "*DEBUG* view\n")
(parameterize ((current-subcommand subcommand))
;; TODO: !!!
(void)))
;; Abbreviations:
((equal? subcommand "dl") (loop-subcommand "dev-links"))
((equal? subcommand "sa") (loop-subcommand "setup-all"))
((equal? subcommand "sp") (loop-subcommand "setup-package"))
((equal? subcommand "v") (loop-subcommand "view"))
;; Error:
(else
(fatal-command-line-error "Invalid subcommand ~S"
subcommand))))
(printf "*DEBUG* fell out of loop-subcommand\n")
;; TODO: !!!
))
--
http://www.neilvandyke.org/
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