ui: Add 'make-regexp*'.

Fixes <http://bugs.gnu.org/21773>.
Reported by Jan Synáček <jan.synacek@gmail.com>.

* guix/ui.scm (make-regexp*): New procedure.
* guix/scripts/package.scm (options->installable, guix-package): Use it
  when processing user-provided regexps.

1 files changed, 11 insertions, 0 deletions

diff --git a/guix/ui.scm b/guix/ui.scm
index 72208e7de7..312c2a01a1 100644
--- a/guix/ui.scm
+++ b/guix/ui.scm
@@ -61,6 +61,7 @@
             warn-about-load-error
             show-version-and-exit
             show-bug-report-information
+            make-regexp*
             string->number*
             size->number
             show-derivation-outputs
@@ -350,6 +351,16 @@ General help using GNU software: <http://www.gnu.org/gethelp/>"))
                  (list (strerror (car errno)) target)
                  (list errno)))))))
 
+(define (make-regexp* regexp . flags)
+  "Like 'make-regexp' but error out if REGEXP is invalid, reporting the error
+nicely."
+  (catch 'regular-expression-syntax
+    (lambda ()
+      (apply make-regexp regexp flags))
+    (lambda (key proc message . rest)
+      (leave (_ "'~a' is not a valid regular expression: ~a~%")
+             regexp message))))
+
 (define (string->number* str)
   "Like `string->number', but error out with an error message on failure."
   (or (string->number str)