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authorLudovic Courtès <ludo@gnu.org>2017-04-05 15:19:15 +0200
committerLudovic Courtès <ludo@gnu.org>2017-04-05 22:45:41 +0200
commitf37f2b83fa95c1fe2bf01c4b8072cfc23d4c67ec (patch)
treebed6bac6a29ee4575fdbf34604bd380f0d5c2ff7 /guix
parent79f912c7106131f4179c727583d33500271361cd (diff)
packages: Add 'package-mapping' and base 'package-input-rewriting' on it.
* guix/packages.scm (package-mapping): New procedure. (package-input-rewriting): Rewrite in terms of 'package-mapping'. * tests/packages.scm ("package-mapping"): New test. * doc/guix.texi (Defining Packages): Document it.
Diffstat (limited to 'guix')
-rw-r--r--guix/packages.scm56
1 files changed, 37 insertions, 19 deletions
diff --git a/guix/packages.scm b/guix/packages.scm
index b68b3de6d2..44f2c32fb7 100644
--- a/guix/packages.scm
+++ b/guix/packages.scm
@@ -98,6 +98,7 @@
package-transitive-propagated-inputs
package-transitive-native-search-paths
package-transitive-supported-systems
+ package-mapping
package-input-rewriting
package-source-derivation
package-derivation
@@ -741,36 +742,53 @@ dependencies are known to build on SYSTEM."
"Return the \"target inputs\" of BAG, recursively."
(transitive-inputs (bag-target-inputs bag)))
-(define* (package-input-rewriting replacements
- #:optional (rewrite-name identity))
- "Return a procedure that, when passed a package, replaces its direct and
-indirect dependencies (but not its implicit inputs) according to REPLACEMENTS.
-REPLACEMENTS is a list of package pairs; the first element of each pair is the
-package to replace, and the second one is the replacement.
-
-Optionally, REWRITE-NAME is a one-argument procedure that takes the name of a
-package and returns its new name after rewrite."
+(define* (package-mapping proc #:optional (cut? (const #f)))
+ "Return a procedure that, given a package, applies PROC to all the packages
+depended on and returns the resulting package. The procedure stops recursion
+when CUT? returns true for a given package."
(define (rewrite input)
(match input
((label (? package? package) outputs ...)
- (match (assq-ref replacements package)
- (#f (cons* label (replace package) outputs))
- (new (cons* label new outputs))))
+ (let ((proc (if (cut? package) proc replace)))
+ (cons* label (proc package) outputs)))
(_
input)))
(define replace
(mlambdaq (p)
- ;; Return a variant of P with its inputs rewritten.
- (package
- (inherit p)
- (name (rewrite-name (package-name p)))
- (inputs (map rewrite (package-inputs p)))
- (native-inputs (map rewrite (package-native-inputs p)))
- (propagated-inputs (map rewrite (package-propagated-inputs p))))))
+ ;; Return a variant of P with PROC applied to P and its explicit
+ ;; dependencies, recursively. Memoize the transformations. Failing to
+ ;; do that, we would build a huge object graph with lots of duplicates,
+ ;; which in turns prevents us from benefiting from memoization in
+ ;; 'package-derivation'.
+ (let ((p (proc p)))
+ (package
+ (inherit p)
+ (location (package-location p))
+ (inputs (map rewrite (package-inputs p)))
+ (native-inputs (map rewrite (package-native-inputs p)))
+ (propagated-inputs (map rewrite (package-propagated-inputs p)))))))
replace)
+(define* (package-input-rewriting replacements
+ #:optional (rewrite-name identity))
+ "Return a procedure that, when passed a package, replaces its direct and
+indirect dependencies (but not its implicit inputs) according to REPLACEMENTS.
+REPLACEMENTS is a list of package pairs; the first element of each pair is the
+package to replace, and the second one is the replacement.
+
+Optionally, REWRITE-NAME is a one-argument procedure that takes the name of a
+package and returns its new name after rewrite."
+ (define (rewrite p)
+ (match (assq-ref replacements p)
+ (#f (package
+ (inherit p)
+ (name (rewrite-name (package-name p)))))
+ (new new)))
+
+ (package-mapping rewrite (cut assq <> replacements)))
+
;;;
;;; Package derivations.