getopt-long

getopt-long

[Andrew Horton]

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Recently I needed to be able to recognize multiple use of an option when 
using getopt-long. For example, the gcc "-L" option can be specified 
multiple times for various paths. The option-ref helper function only 
seems to get the most recent use of an option using assq. I couldn't see 
any other way in the getopt-long API to do it, so added a helper 
function option-ref-list (see patch vs stable-2.0).

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From 66723614a07b73d87cd018d2944e9f6040c8933c Mon Sep 17 00:00:00 2001
From: Andrew Horton <andrew.j.horton@gmail.com>
Date: Wed, 30 Nov 2011 22:46:26 +0000
Subject: [PATCH] Add a function, option-ref-list, to getopt-long to allow
 multiple values to be retrieved for a specified argument.

---
 doc/ref/mod-getopt-long.texi |   25 +++++++++++++++++++++++--
 module/ice-9/getopt-long.scm |   12 +++++++++++-
 2 files changed, 34 insertions(+), 3 deletions(-)

diff --git a/doc/ref/mod-getopt-long.texi b/doc/ref/mod-getopt-long.texi
index 07fab81..745f5a6 100644
--- a/doc/ref/mod-getopt-long.texi
+++ b/doc/ref/mod-getopt-long.texi
@@ -7,8 +7,8 @@
 @node getopt-long
 @section The (ice-9 getopt-long) Module
 
-The @code{(ice-9 getopt-long)} module exports two procedures:
-@code{getopt-long} and @code{option-ref}.
+The @code{(ice-9 getopt-long)} module exports three procedures:
+@code{getopt-long}, @code{option-ref}, and @code{option-ref-list}.
 
 @itemize @bullet
 @item
@@ -21,6 +21,12 @@ structure that encapsulates the results of the parsing.
 @item
 @code{option-ref} then takes the parsed data structure and a specific
 option's name, and returns information about that option in particular.
+
+@item
+@code{option-ref-list} also takes the parsed data structure and a specific
+option's name, but returns a list of matching options. This is useful if
+you want to allow an option to be specified multiple times with different
+values.
 @end itemize
 
 To make these procedures available to your Guile script, include the
@@ -33,6 +39,7 @@ top, before the first usage of @code{getopt-long} or @code{option-ref}.
 * Command Line Format::         The expected command line format.
 * getopt-long Reference::       Full documentation for @code{getopt-long}.
 * option-ref Reference::        Full documentation for @code{option-ref}.
+* option-ref-list Reference::        Full documentation for @code{option-ref-list}.
 @end menu
 
 
@@ -359,3 +366,17 @@ option value from the command line, or the default value.
 
 The special key @code{'()} can be used to get a list of all
 non-option arguments.
+
+@node option-ref-list Reference
+@subsection Reference Documentation for @code{option-ref-list}
+
+@deffn {Scheme Procedure} option-ref-list options key default
+Search @var{options} for any command line option named @var{key} and
+return a list of matching values, if found. If none were found, @var{default}
+is returned. This variant of @code{option-ref} is useful if you want the
+user to be able to specify an option/value pair multiple times.
+@var{options} must be the result of a call to @code{getopt-long}.
+@end deffn
+
+@code{option-ref-list} always succeeds, either by returning the requested
+option value from the command line, or the default value.
diff --git a/module/ice-9/getopt-long.scm b/module/ice-9/getopt-long.scm
index 930ac0d..38d5a32 100644
--- a/module/ice-9/getopt-long.scm
+++ b/module/ice-9/getopt-long.scm
@@ -158,11 +158,12 @@
 
 (define-module (ice-9 getopt-long)
   #:use-module ((ice-9 common-list) #:select (remove-if-not))
+  #:use-module (srfi srfi-1)
   #:use-module (srfi srfi-9)
   #:use-module (ice-9 match)
   #:use-module (ice-9 regex)
   #:use-module (ice-9 optargs)
-  #:export (getopt-long option-ref))
+  #:export (getopt-long option-ref option-ref-list))
 
 (define %program-name (make-fluid "guile"))
 (define (program-name)
@@ -369,4 +370,13 @@ to add a `single-char' clause to the option description."
 The value is either a string or `#t'."
   (or (assq-ref options key) default))
 
+(define (option-ref-list options key default)
+  "Return list of matching values in alist OPTIONS using KEY, a symbol; or DEFAULT if not found."
+  (let ((vals (fold (lambda (x l)
+                      (if (eq? key (car x))
+                          (cons (cdr x) l)
+                          l))
+                    '() options)))
+    (if (null? vals) default vals)))
+
 ;;; getopt-long.scm ends here
-- 
1.7.8.rc4

Re: getopt-long

[Ludovic Courtès]

Hi Andrew,

Andrew Horton <andrew.j.horton@gmail.com> skribis:

> Recently I needed to be able to recognize multiple use of an option
> when using getopt-long.

This would be an incompatible change, so I’d rather not do it.

However, I’d recommend using SRFI-37: it supports multiple occurrences
of an option, and has a nicer interface IMO.

Thanks,
Ludo’.

Re: getopt-long

[Andy Wingo]

On Mon 05 Dec 2011 18:14, ludo@gnu.org (Ludovic Courtès) writes:

> However, I’d recommend using SRFI-37: it supports multiple occurrences
> of an option, and has a nicer interface IMO.

I like it too, but I use both, and if we can make getopt-long more
useful, there doesn't seem to be any harm in that.

Andy
-- 
http://wingolog.org/

Re: getopt-long

[Thien-Thi Nguyen]

() Andrew Horton <andrew.j.horton@gmail.com>
() Thu, 01 Dec 2011 11:40:40 +0000

   recognize multiple use of an option when using getopt-long.

Guile 1.4.x extended (ice-9 getopt-long) to handle multiple occurances.
Here is an excerpt from (info "(guile) getopt-long Reference"):

  `(merge-multiple? BOOL)'
        If BOOL is `#t' and the `value' property is not `#f', all
        (one or multiple) occurrances are merged into a list with
        order retained.  If `#f', each instance of the option results
        in a separate entry in the resulting alist.

Subsequently, this rat jumped to the non-(not-yet?)-sinking ttn-do
as module ‘(ttn-do zzz bamboozled)’.  More info online:

http://www.gnuvola.org/software/guile/doc/getopt_002dlong-Reference.html
http://www.gnuvola.org/software/ttn-do/ttn-do.html.gz#zzz-bamboozled

I think it would be cool if this were to find berth in official Guile.

Re: getopt-long

[Andrew Horton]

That would do the trick. I've also thought that a (help "...") for
each option would also be useful, which could append the string for
each arg to the "--help" option text automatically (somehow).

On 5 December 2011 18:35, Thien-Thi Nguyen <ttn@gnuvola.org> wrote:
> () Andrew Horton <andrew.j.horton@gmail.com>
> () Thu, 01 Dec 2011 11:40:40 +0000
>
>   recognize multiple use of an option when using getopt-long.
>
> Guile 1.4.x extended (ice-9 getopt-long) to handle multiple occurances.
> Here is an excerpt from (info "(guile) getopt-long Reference"):
>
>  `(merge-multiple? BOOL)'
>        If BOOL is `#t' and the `value' property is not `#f', all
>        (one or multiple) occurrances are merged into a list with
>        order retained.  If `#f', each instance of the option results
>        in a separate entry in the resulting alist.
>
> Subsequently, this rat jumped to the non-(not-yet?)-sinking ttn-do
> as module ‘(ttn-do zzz bamboozled)’.  More info online:
>
> http://www.gnuvola.org/software/guile/doc/getopt_002dlong-Reference.html
> http://www.gnuvola.org/software/ttn-do/ttn-do.html.gz#zzz-bamboozled
>
> I think it would be cool if this were to find berth in official Guile.

Re: getopt-long

[Andy Wingo]

On Mon 05 Dec 2011 19:35, Thien-Thi Nguyen <ttn@gnuvola.org> writes:

> Guile 1.4.x extended (ice-9 getopt-long) to handle multiple occurances.
> Here is an excerpt from (info "(guile) getopt-long Reference"):
>
>   `(merge-multiple? BOOL)'
>         If BOOL is `#t' and the `value' property is not `#f', all
>         (one or multiple) occurrances are merged into a list with
>         order retained.  If `#f', each instance of the option results
>         in a separate entry in the resulting alist.

That would be a compatible change, no?  A patch would be gladly accepted
:)

Regards,

Andy
-- 
http://wingolog.org/

Re: getopt-long

[Ludovic Courtès]

Hi,

Andy Wingo <wingo@pobox.com> skribis:

> On Mon 05 Dec 2011 19:35, Thien-Thi Nguyen <ttn@gnuvola.org> writes:
>
>> Guile 1.4.x extended (ice-9 getopt-long) to handle multiple occurances.
>> Here is an excerpt from (info "(guile) getopt-long Reference"):
>>
>>   `(merge-multiple? BOOL)'
>>         If BOOL is `#t' and the `value' property is not `#f', all
>>         (one or multiple) occurrances are merged into a list with
>>         order retained.  If `#f', each instance of the option results
>>         in a separate entry in the resulting alist.
>
> That would be a compatible change, no?

Indeed, that would be OK.

Thanks,
Ludo’.

Re: getopt-long

[Thien-Thi Nguyen]

() Andy Wingo <wingo@pobox.com>
() Mon, 05 Dec 2011 21:51:06 +0100

   That would be a compatible change, no?

I believe so.

   A patch would be gladly accepted :)

Also for 1.8.x?

Re: getopt-long

[Andy Wingo]

On Tue 06 Dec 2011 15:13, Thien-Thi Nguyen <ttn@gnuvola.org> writes:

>    A patch would be gladly accepted :)
>
> Also for 1.8.x?

If you want to, sure.

Thanks!

Andy
-- 
http://wingolog.org/