-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1
Mike Frysinger wrote:
> On Tuesday 30 October 2007, Marijn Schouten (hkBst) wrote:
>> The purpose of this patch is to expose a generic function, namely _use,
>> which can be used to build your own use* variant if you need that. I
>> reimplemented all other current use function using _use (and _if) to cut
>> out duplicate and verbose code. Comments expected. I didn't test this code.
>
> i guess i dont really see it ... there isnt that much duplicate code to begin
> with, and the end result is kind of hard to understand at first glance which
> is a bad thing ...
> -mike
I hope this is just an artifact of the patch being a bit opaque. The
inconsistent indentation in the patch is a consequence of emacs bash mode
using a different indentation style than (I guess) vi(m). I'm sure even in vi
you can re-indent my code with one simple key-chord.
The immediate motivation of my examining this code was a request on
#gentoo-dev-help by lack for something which I could with my new code easily
write like this:
use_mime() {
local WORD="$(_if $2 $2 $1)"
_use $1 "${WORD};"
}
This is possible because besides being shorter, my code is more general and
exposes utility functions to write your own use_* functions with.
The explanation of this function is:
#set WORD to argument 2 or if that is empty to argument 1
#output "${WORD};" if use flag $1 is set
I don't think it gets any clearer/directer/shorter than that. Other existing
functions that are trivial to re-implement:
use() {
_use ${1}
}
useq() {
_use ${1}
}
usev() {
_use ${1} ${1}
}
use_with() {
local SUFFIX="$(_if $3 "=$3")"
local WORD="$(_if $2 $2 $1)"
_use $1 "--with-${WORD}${SUFFIX}" "--without-${WORD}"
}
use_enable() {
local SUFFIX="$(_if $3 "=$3")"
local WORD="$(_if $2 $2 $1)"
_use $1 "--enable-${WORD}${SUFFIX}" "--disable-${WORD}"
}
All that is needed is:
_if() {
if $1; then echo $2; else echo $3; fi
}
and a function which is slightly extended from what is now useq to allow for
choosing to echo strings. Please excuse some line-wrapping.
_use() {
local flag=$1
local string_success=$2
local string_failure=$3
local found=0
# invert the return value for "!blah" and strip the '!'
[[ ${flag} = !* ]] && { found=1 ; flag=${flag:1} }
# Make sure we have this USE flag in IUSE
if ! hasq "${flag}" ${IUSE} ${E_IUSE} && ! hasq "${flag}"
${PORTAGE_ARCHLIST} selinux; then
eqawarn "QA Notice: USE Flag '${flag}' not in IUSE for
${CATEGORY}/${PF}"
fi
if hasq ${flag} ${USE} ; then
echo ${string_success}; return ${found}
else
echo ${string_failure}; return $((!found))
fi
}
What's not to like?
Marijn
- --
Marijn Schouten (hkBst), Gentoo Lisp project
<http://www.gentoo.org/proj/en/lisp/>, #gentoo-lisp on FreeNode
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v2.0.7 (GNU/Linux)
Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org
iD8DBQFHKHQ6p/VmCx0OL2wRAl4dAJ4ilITOLQapD2NXCenw+YOYMPyOxwCgunjt
yKFi0LaXlEzAKQYnO2BS1SI=
=XQvd
-----END PGP SIGNATURE-----
--
[EMAIL PROTECTED] mailing list
