ui: Remove dependency on (gnu system file-systems).

* guix/ui.scm (specification->file-system-mapping): Move to...
* gnu/system/file-systems.scm (specification->file-system-mapping):
... here.

1 files changed, 18 insertions, 0 deletions

diff --git a/gnu/system/file-systems.scm b/gnu/system/file-systems.scm
index f4cfaf0990..116e2813e8 100644
--- a/gnu/system/file-systems.scm
+++ b/gnu/system/file-systems.scm
@@ -40,6 +40,7 @@
             file-system-dependencies
 
             file-system->spec
+            specification->file-system-mapping
             uuid
 
             %fuse-control-file-system
@@ -105,6 +106,23 @@ initrd code."
     (($ <file-system> device title mount-point type flags options _ _ check?)
      (list device title mount-point type flags options check?))))
 
+(define (specification->file-system-mapping spec writable?)
+  "Read the SPEC and return the corresponding <file-system-mapping>.  SPEC is
+a string of the form \"SOURCE\" or \"SOURCE=TARGET\".  The former specifies
+that SOURCE from the host should be mounted at SOURCE in the other system.
+The latter format specifies that SOURCE from the host should be mounted at
+TARGET in the other system."
+  (let ((index (string-index spec #\=)))
+    (if index
+        (file-system-mapping
+         (source (substring spec 0 index))
+         (target (substring spec (+ 1 index)))
+         (writable? writable?))
+        (file-system-mapping
+         (source spec)
+         (target spec)
+         (writable? writable?)))))
+
 (define-syntax uuid
   (lambda (s)
     "Return the bytevector corresponding to the given UUID representation."