git: Abstract temporary checkout.

* tissue/git.scm (call-with-temporary-checkout,
call-with-temporary-checkouts): New public functions.
* .dir-locals.el (scheme-mode): Set scheme-indent-function of
call-with-temporary-checkout and call-with-temporary-checkouts to 1.

1 files changed, 22 insertions, 1 deletions

diff --git a/tissue/git.scm b/tissue/git.scm
index 562e715..653f8ae 100644
--- a/tissue/git.scm
+++ b/tissue/git.scm
@@ -47,7 +47,9 @@
             git-tracked-files
             call-with-file-in-git
             file-modification-table
-            clone-options))
+            clone-options
+            call-with-temporary-checkout
+            call-with-temporary-checkouts))
 
 ;; We bind additional functions from libgit2 that are not already
 ;; bound in guile-git. TODO: Contribute them to guile-git.
@@ -211,3 +213,22 @@ that modified them."
      'bare
      (if bare? 1 0))
     clone-options))
+
+(define (call-with-temporary-checkout repository proc)
+  "Call PROC with a temporary checkout of REPOSITORY, and delete the
+checkout when PROC returns or exits non-locally."
+  (call-with-temporary-directory
+   (lambda (temporary-checkout)
+     (clone repository temporary-checkout)
+     (proc temporary-checkout))))
+
+(define (call-with-temporary-checkouts repositories proc)
+  "Call PROC with temporary checkouts of REPOSITORIES, and delete the
+checkouts when PROC returns or exits non-locally."
+  (match repositories
+    ((repository other-repositories ...)
+     (call-with-temporary-checkout repository
+       (lambda (checkout)
+         (call-with-temporary-checkouts other-repositories
+           (cut proc checkout <...>)))))
+    (() (proc))))