Merge branch 'master' into core-updates

1 files changed, 32 insertions, 1 deletions

diff --git a/guix/ui.scm b/guix/ui.scm
index 382b5b1e0d..ae37c8e6ca 100644
--- a/guix/ui.scm
+++ b/guix/ui.scm
@@ -3,6 +3,7 @@
 ;;; Copyright © 2013 Mark H Weaver <mhw@netris.org>
 ;;; Copyright © 2013 Nikita Karetnikov <nikita@karetnikov.org>
 ;;; Copyright © 2014 Alex Kost <alezost@gmail.com>
+;;; Copyright © 2014 Deck Pickard <deck.r.pickard@gmail.com>
 ;;;
 ;;; This file is part of GNU Guix.
 ;;;
@@ -66,7 +67,7 @@
             string->generations
             string->duration
             args-fold*
-            environment-build-options
+            parse-command-line
             run-guix-command
             program-name
             guix-warning-port
@@ -754,6 +755,36 @@ reporting."
   "Return additional build options passed as environment variables."
   (arguments-from-environment-variable "GUIX_BUILD_OPTIONS"))
 
+(define %default-argument-handler
+  ;; The default handler for non-option command-line arguments.
+  (lambda (arg result)
+    (alist-cons 'argument arg result)))
+
+(define* (parse-command-line args options seeds
+                             #:key
+                             (argument-handler %default-argument-handler))
+  "Parse the command-line arguments ARGS as well as arguments passed via the
+'GUIX_BUILD_OPTIONS' environment variable according to OPTIONS (a list of
+SRFI-37 options) and return the result, seeded by SEEDS.
+Command-line options take precedence those passed via 'GUIX_BUILD_OPTIONS'.
+
+ARGUMENT-HANDLER is called for non-option arguments, like the 'operand-proc'
+parameter of 'args-fold'."
+  (define (parse-options-from args seeds)
+    ;; Actual parsing takes place here.
+    (apply args-fold* args options
+           (lambda (opt name arg . rest)
+             (leave (_ "~A: unrecognized option~%") name))
+           argument-handler
+           seeds))
+
+  (call-with-values
+      (lambda ()
+        (parse-options-from (environment-build-options) seeds))
+    (lambda seeds
+      ;; ARGS take precedence over what the environment variable specifies.
+      (parse-options-from args seeds))))
+
 (define (show-guix-usage)
   (format (current-error-port)
           (_ "Try `guix --help' for more information.~%"))