import: Factorize utility functions.

* guix/import/pypi.scm (hash-table->alist, flatten, assoc-ref*,
  url-fetch, json-fetch): Pull procedures from here into...
* guix/import/utils.scm: Here and...
* guix/import/json.scm: Here.  New file.
* Makefile.am (MODULE)[HAVE_GUILE_JSON]: Add it.
* guix/import/gnu.scm (file-sha256): Move from here to...
* guix/hash.scm: Here.
* tests/pypi.scm (pypi->guix-package): Update mock module reference.

1 files changed, 5 insertions, 0 deletions

diff --git a/guix/hash.scm b/guix/hash.scm
index fb85f47586..593c2e1aee 100644
--- a/guix/hash.scm
+++ b/guix/hash.scm
@@ -26,6 +26,7 @@
   #:export (sha256
             open-sha256-port
             port-sha256
+            file-sha256
             open-sha256-input-port))
 
 ;;; Commentary:
@@ -129,6 +130,10 @@ output port."
     (close-port out)
     (get)))
 
+(define (file-sha256 file)
+  "Return the SHA256 hash (a bytevector) of FILE."
+  (call-with-input-file file port-sha256))
+
 (define (open-sha256-input-port port)
   "Return an input port that wraps PORT and a thunk to get the hash of all the
 data read from PORT.  The thunk always returns the same value."