02/07: substitute: Avoid repeated calls to 'length'.

[Ludovic Courtès]

civodul pushed a commit to branch master
in repository guix.

commit 75a4d86f50e1682b96c51eb46a6aba24afc25d03
Author: Ludovic Courtès <address@hidden>
Date:   Fri Jul 21 14:13:58 2017 +0200

    substitute: Avoid repeated calls to 'length'.
    
    * guix/scripts/substitute.scm (fetch-narinfos)[update-progress!]: Move
    'length' call outside of lambda.
---
 guix/scripts/substitute.scm | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/guix/scripts/substitute.scm b/guix/scripts/substitute.scm
index c066016..35282f9 100755
--- a/guix/scripts/substitute.scm
+++ b/guix/scripts/substitute.scm
@@ -601,13 +601,14 @@ if file doesn't exist, and the narinfo otherwise."
 (define (fetch-narinfos url paths)
   "Retrieve all the narinfos for PATHS from the cache at URL and return them."
   (define update-progress!
-    (let ((done 0))
+    (let ((done 0)
+          (total (length paths)))
       (lambda ()
         (display #\cr (current-error-port))
         (force-output (current-error-port))
         (format (current-error-port)
                 (G_ "updating list of substitutes from '~a'... ~5,1f%")
-                url (* 100. (/ done (length paths))))
+                url (* 100. (/ done total)))
         (set! done (+ 1 done)))))
 
   (define hash-part->path