Re: defcustom: order matters in `choice' with value-to-internal

[Andreas Schwab <schwab@suse.de>]

Reiner Steib <reinersteib+gmane@imap.cc> writes:

> consider these two defcustoms, which only differ in the order of the
> choice elements:
>
> (defcustom rs-test-1
>   "^From:\\|^Newsgroups:\\|^Subject:"
>   "doc string 1, list of regexps, regexp or nil"
>   :type '(choice
> 	  (const nil :tag "Use gnus-ignored-headers")
> 	  regexp
> 	  (repeat :value-to-internal (lambda (widget value)
> 				       (custom-split-regexp-maybe value))
> 		  :match (lambda (widget value)
> 			   (or (stringp value)
> 			       (widget-editable-list-match widget value)))
> 		  regexp)))
>
> (defcustom rs-test-2
>   "^From:\\|^Newsgroups:\\|^Subject:"
>   "doc string 2, list of regexps, regexp or nil"
>   :type '(choice
> 	  (repeat :value-to-internal (lambda (widget value)
> 				       (custom-split-regexp-maybe value))
> 		  :match (lambda (widget value)
> 			   (or (stringp value)
> 			       (widget-editable-list-match widget value)))
> 		  regexp)
> 	  (const nil :tag "Use gnus-ignored-headers")
> 	  regexp))

Order generally matters, the first matching choice is used.  There is
nothing else that favors the repeat over regexp.

Andreas.

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Andreas Schwab, SuSE Labs, schwab@suse.de
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