| Message ID | 08db559a4e24a409d332b3552d6a176de6353166.1631867018.git.public@yoctocell.xyz |
|---|---|
| State | New |
| Headers | show |
| Series | [bug#50614] build: utils: Add ‘list-when’ macro. | expand |
| Context | Check | Description |
|---|---|---|
| cbaines/applying patch | fail | View Laminar job |
| cbaines/issue | success | View issue |
Am Freitag, den 17.09.2021, 10:26 +0200 schrieb Xinglu Chen: > * guix/build/utils.scm (list-when): New syntax > * tests/build-utils.scm ("list-when: expr1 is non-#f", list-when: > expr1 is #f"): > Test it. > * guix.texi (Build Utilities): Document it. > --- > Changes since v1: > > * Rename ‘optional’ to ‘list-when’. > > * Make > > (list-when test consequent ...) > > equivalent to > > (if tests > (list consequent ...) > '()) LGTM, but let's wait on more opinions. IIRC, changing (guix build) causes a world rebuild, no? So this patch might go to core-updates first.
Hi, Liliana Marie Prikler <liliana.prikler@gmail.com> writes: > Am Freitag, den 17.09.2021, 10:26 +0200 schrieb Xinglu Chen: >> * guix/build/utils.scm (list-when): New syntax >> * tests/build-utils.scm ("list-when: expr1 is non-#f", list-when: >> expr1 is #f"): >> Test it. >> * guix.texi (Build Utilities): Document it. >> --- >> Changes since v1: >> >> * Rename ‘optional’ to ‘list-when’. >> >> * Make >> >> (list-when test consequent ...) >> >> equivalent to >> >> (if tests >> (list consequent ...) >> '()) > LGTM, but let's wait on more opinions. IIRC, changing (guix build) > causes a world rebuild, no? So this patch might go to core-updates > first. Do we actually use this idiom anywhere build-side? (If not, does it belong in (guix utils)? Or should we stick it in (guix build utils) just to be safe?) -- Sarah
Hi, Looking at this again I have a couple more comments. Xinglu Chen <public@yoctocell.xyz> writes: > +@cindex miscellaneous build utilities > +This section documents some miscellaneous utilities that are useful to > +have. "that are useful to have" is implied by its presence in the manual, so it's unnecessary to write it. Also, you might consider adding a rule to .dir-locals.el: (eval . (put list-when 'scheme-indent-function 1)) which would cause it to be indented like this: (list-when expr1 expr2 expr3) (I pointed out a couple other minor grammar corrections in the last review--did you see those?) -- Sarah
Am Freitag, den 17.09.2021, 12:15 -0700 schrieb Sarah Morgensen: > Do we actually use this idiom anywhere build-side? (If not, does it > belong in (guix utils)? Or should we stick it in (guix build utils) > just to be safe?) I'm pretty sure that this would mostly be used in quasi-quoted contexts outside of the actual build to build #:configure-flags, #:make-flags and inputs. However, I can't really say there'd be no use of it inside builds, even if builds typically don't need to check for conditionals other than tests?
Liliana Marie Prikler schreef op vr 17-09-2021 om 19:55 [+0200]: > Am Freitag, den 17.09.2021, 10:26 +0200 schrieb Xinglu Chen: > > * guix/build/utils.scm (list-when): New syntax > > * tests/build-utils.scm ("list-when: expr1 is non-#f", list-when: > > expr1 is #f"): > > Test it. > > * guix.texi (Build Utilities): Document it. > > --- > > Changes since v1: > > > > * Rename ‘optional’ to ‘list-when’. > > > > * Make > > > > (list-when test consequent ...) > > > > equivalent to > > > > (if tests > > (list consequent ...) > > '()) > LGTM, but let's wait on more opinions. It looks nice to me, though you might want an opinion from someone who is new to Scheme. Greetings, Maxime.
On Fri, Sep 17 2021, Liliana Marie Prikler wrote: > Am Freitag, den 17.09.2021, 10:26 +0200 schrieb Xinglu Chen: >> * guix/build/utils.scm (list-when): New syntax >> * tests/build-utils.scm ("list-when: expr1 is non-#f", list-when: >> expr1 is #f"): >> Test it. >> * guix.texi (Build Utilities): Document it. >> --- >> Changes since v1: >> >> * Rename ‘optional’ to ‘list-when’. >> >> * Make >> >> (list-when test consequent ...) >> >> equivalent to >> >> (if tests >> (list consequent ...) >> '()) > LGTM, but let's wait on more opinions. IIRC, changing (guix build) > causes a world rebuild, no? So this patch might go to core-updates > first. Sorry, I forgot to add ‘core-updates’ to the subject prefix.
On Fri, Sep 17 2021, Sarah Morgensen wrote: > Hi, > > Looking at this again I have a couple more comments. > > Xinglu Chen <public@yoctocell.xyz> writes: >> +@cindex miscellaneous build utilities >> +This section documents some miscellaneous utilities that are useful to >> +have. > > "that are useful to have" is implied by its presence in the manual, so > it's unnecessary to write it. Good point. > Also, you might consider adding a rule to .dir-locals.el: > > (eval . (put list-when 'scheme-indent-function 1)) > > which would cause it to be indented like this: > > (list-when expr1 > expr2 > expr3) Yes, that would be a good idea. > (I pointed out a couple other minor grammar corrections in the last > review--did you see those?) Oops, looks like I missed those. I will send a v2 with the suggestions applied. :-)
diff --git a/doc/guix.texi b/doc/guix.texi index 9a3e8ae12c..3b469c04c9 100644 --- a/doc/guix.texi +++ b/doc/guix.texi @@ -8801,6 +8801,41 @@ in a build phase of the @code{wireguard-tools} package: `("PATH" ":" prefix ,(list coreutils)))))) @end lisp +@subsection Miscellaneous + +@cindex miscellaneous build utilities +This section documents some miscellaneous utilities that are useful to +have. + +@deffn {Scheme Syntax} list-when @var{test} @var{consequent} @dots{} +Like @code{when} (@pxref{Conditionals,,, guile, GNU Guile Reference +Manual}), but if @var{test} evaluates to true, return @code{(list +@var{consequent} @dots{})}, and if @var{test} evaluates to false, return +the empty list. This is replaces the following idiom: +@end deffn + +@lisp +(if @var{test} + (list @var{consequent} @dots{}) + '()) +@end lisp + +with this: + +@lisp +(list-when @var{test} @var{consequent} @dots{}) +@end lisp + +It can be useful when certain targets require an additional configure +flags, e.g., + +@lisp +(arguments + `(#:configure-flags (list "--localstatedir=/var" + "--sysconfdir=/etc" + ,@@(list-when (hurd-target?) "--with-courage")))) +@end lisp + @subsection Build Phases @cindex build phases diff --git a/guix/build/utils.scm b/guix/build/utils.scm index 3beb7da67a..d3fb207ee5 100644 --- a/guix/build/utils.scm +++ b/guix/build/utils.scm @@ -8,6 +8,7 @@ ;;; Copyright © 2020 Efraim Flashner <efraim@flashner.co.il> ;;; Copyright © 2020, 2021 Maxim Cournoyer <maxim.cournoyer@gmail.com> ;;; Copyright © 2021 Maxime Devos <maximedevos@telenet.be> +;;; Copyright © 2021 Xinglu Chen <public@yoctocell.xyz> ;;; ;;; This file is part of GNU Guix. ;;; @@ -123,7 +124,9 @@ make-desktop-entry-file - locale-category->string)) + locale-category->string + + list-when)) ;;; @@ -1613,6 +1616,18 @@ returned." LC_NAME LC_NUMERIC LC_PAPER LC_TELEPHONE LC_TIME))) + +;;; +;;; Misc. +;;; + +;; If EXPR1 evaluates to a non-#f value, return '(EXPR2 ...). Otherwise, +;; return an empty list. +(define-syntax list-when + (syntax-rules () + ((_ expr1 expr2 ...) + (if expr1 (list expr2 ...) '())))) + ;;; Local Variables: ;;; eval: (put 'call-with-output-file/atomic 'scheme-indent-function 1) ;;; eval: (put 'call-with-ascii-input-file 'scheme-indent-function 1) diff --git a/tests/build-utils.scm b/tests/build-utils.scm index 6b131c0af8..b558feb47d 100644 --- a/tests/build-utils.scm +++ b/tests/build-utils.scm @@ -3,6 +3,7 @@ ;;; Copyright © 2019 Ricardo Wurmus <rekado@elephly.net> ;;; Copyright © 2021 Maxim Cournoyer <maxim.cournoyer@gmail.com> ;;; Copyright © 2021 Maxime Devos <maximedevos@telenet.be> +;;; Copyright © 2021 Xinglu Chen <public@yoctocell.xyz> ;;; ;;; This file is part of GNU Guix. ;;; @@ -287,5 +288,12 @@ print('hello world')")) ("guile/bin" . ,(dirname (which "guile")))) "guile")))) +(test-equal "list-when: expr1 is non-#f" + (list 3 'bar) + (list-when 'foo (+ 1 2) 'bar)) + +(test-equal "list-when: expr1 is #f" + '() + (list-when #f (+ 2 3) 'bar)) (test-end)
* guix/build/utils.scm (list-when): New syntax * tests/build-utils.scm ("list-when: expr1 is non-#f", list-when: expr1 is #f"): Test it. * guix.texi (Build Utilities): Document it. --- Changes since v1: * Rename ‘optional’ to ‘list-when’. * Make (list-when test consequent ...) equivalent to (if tests (list consequent ...) '()) doc/guix.texi | 35 +++++++++++++++++++++++++++++++++++ guix/build/utils.scm | 17 ++++++++++++++++- tests/build-utils.scm | 8 ++++++++ 3 files changed, 59 insertions(+), 1 deletion(-) base-commit: 22f7d4bce1e694b7ac38e62410d76a6d46d96c5d