[bug#78277] ui: Allow evaluating multi-expressions strings with read/eval.
Commit Message
This can be useful when evaluating a scheme->file store output for example,
which has multiple top level expressions.
* guix/ui.scm (read/eval): Also accept a port object as argument. Read and
evaluate all expressions from input port or string.
Change-Id: I0213706fa4824c3a8ffe5d93f44f263048cb62c2
---
guix/ui.scm | 35 ++++++++++++++++++++++++++---------
1 file changed, 26 insertions(+), 9 deletions(-)
base-commit: a897159a7cdb521d64fd2a5034b6c895968a7f51
Comments
Hi,
Maxim Cournoyer <maxim.cournoyer@gmail.com> writes:
> This can be useful when evaluating a scheme->file store output for example,
> which has multiple top level expressions.
>
> * guix/ui.scm (read/eval): Also accept a port object as argument. Read and
> evaluate all expressions from input port or string.
>
> Change-Id: I0213706fa4824c3a8ffe5d93f44f263048cb62c2
Very useful, thanks!
Perhaps you can add a test for example with ‘guix build -e’ in
‘tests/guix-build.sh’?
Otherwise, LGTM.
Ludo’.
Hi!
Ludovic Courtès <ludo@gnu.org> writes:
> Hi,
>
> Maxim Cournoyer <maxim.cournoyer@gmail.com> writes:
>
>> This can be useful when evaluating a scheme->file store output for example,
>> which has multiple top level expressions.
>>
>> * guix/ui.scm (read/eval): Also accept a port object as argument. Read and
>> evaluate all expressions from input port or string.
>>
>> Change-Id: I0213706fa4824c3a8ffe5d93f44f263048cb62c2
>
> Very useful, thanks!
>
> Perhaps you can add a test for example with ‘guix build -e’ in
> ‘tests/guix-build.sh’?
Done! See commit 18ed22536d0. Thanks for the review!
@@ -15,7 +15,7 @@
;;; Copyright © 2019, 2020 Tobias Geerinckx-Rice <me@tobias.gr>
;;; Copyright © 2019, 2021 Simon Tournier <zimon.toutoune@gmail.com>
;;; Copyright © 2020 Arun Isaac <arunisaac@systemreboot.net>
-;;; Copyright © 2020 Maxim Cournoyer <maxim.cournoyer@gmail.com>
+;;; Copyright © 2020, 2025 Maxim Cournoyer <maxim.cournoyer@gmail.com>
;;; Copyright © 2018 Steve Sprang <scs@stevesprang.com>
;;; Copyright © 2022 Taiju HIGASHI <higashi@taiju.info>
;;; Copyright © 2022 Liliana Marie Prikler <liliana.prikler@gmail.com>
@@ -926,13 +926,18 @@ (define %guix-user-module
module)))
(define (read/eval str)
- "Read and evaluate STR, raising an error if something goes wrong."
- (let ((exp (catch #t
- (lambda ()
- (call-with-input-string str read))
- (lambda args
- (leave (G_ "failed to read expression ~s: ~s~%")
- str args)))))
+ "Read and evaluate STR, which can also be a port, raising an error if
+something goes wrong. STR may contain one or more expressions; the return
+value is that of the last evaluated expression."
+ (define (read/safe port)
+ (catch #t
+ (lambda ()
+ (read port))
+ (lambda args
+ (leave (G_ "failed to read expression ~s: ~s~%")
+ str args))))
+
+ (define (eval/safe exp)
(catch #t
(lambda ()
(eval exp (force %guix-user-module)))
@@ -956,7 +961,19 @@ (define (read/eval str)
((error args ...)
(apply display-error #f (current-error-port) args))
(what? #f))
- (exit 1)))))
+ (exit 1))))
+
+ (let ((call-with-port-or-string (if (port? str)
+ call-with-port
+ call-with-input-string)))
+ (call-with-port-or-string
+ str
+ (lambda (port)
+ (let loop ((exp (read/safe port))
+ (result #f))
+ (if (eof-object? exp)
+ result
+ (loop (read/safe port) (eval/safe exp))))))))
(define (read/eval-package-expression str)
"Read and evaluate STR and return the package it refers to, or exit an