upstream: Define 'url-predicate' and use it.

* guix/upstream.scm (url-predicate): New procedure.
(url-prefix-predicate): Define in terms of 'url-predicate'.
* guix/import/cpan.scm (cpan-package?): Use 'url-predicate'.
* guix/import/cran.scm (cran-package?)
(bioconductor-package?)
(bioconductor-data-package?)
(bioconductor-experiment-package?): Likewise.
* guix/import/crate.scm (crate-package?): Likewise.
* guix/import/elpa.scm (package-from-gnu.org?): Likewise.
* guix/import/hackage.scm (hackage-package?): Likewise.
* guix/import/pypi.scm (pypi-package?): Likewise.
* guix/import/gem.scm (gem-package?): Use 'url-prefix-predicate'.

1 files changed, 3 insertions, 16 deletions

diff --git a/guix/import/hackage.scm b/guix/import/hackage.scm
index dbc1afa4a7..35c67cad8d 100644
--- a/guix/import/hackage.scm
+++ b/guix/import/hackage.scm
@@ -346,22 +346,9 @@ respectively."
                                                   (cons name args)))
                     #:guix-name hackage-name->package-name))
 
-(define (hackage-package? package)
-  "Return #t if PACKAGE is a Haskell package from Hackage."
-
-  (define haskell-url?
-    (let ((hackage-rx (make-regexp "https?://hackage.haskell.org")))
-      (lambda (url)
-        (regexp-exec hackage-rx url))))
-
-  (let ((source-url (and=> (package-source package) origin-uri))
-        (fetch-method (and=> (package-source package) origin-method)))
-    (and (eq? fetch-method url-fetch)
-         (match source-url
-           ((? string?)
-            (haskell-url? source-url))
-           ((source-url ...)
-            (any haskell-url? source-url))))))
+(define hackage-package?
+  (let ((hackage-rx (make-regexp "https?://hackage.haskell.org")))
+    (url-predicate (cut regexp-exec hackage-rx <>))))
 
 (define (latest-release package)
   "Return an <upstream-source> for the latest release of PACKAGE."