diff options
Diffstat (limited to 'gnu/packages.scm')
| -rw-r--r-- | gnu/packages.scm | 36 |
1 files changed, 35 insertions, 1 deletions
diff --git a/gnu/packages.scm b/gnu/packages.scm index 9eb4877be8..6e46a890bb 100644 --- a/gnu/packages.scm +++ b/gnu/packages.scm @@ -51,7 +51,8 @@ check-package-freshness - specification->package)) + specification->package + specification->package+output)) ;;; Commentary: ;;; @@ -418,3 +419,36 @@ present, return the preferred newest version." (leave (_ "~A: package not found for version ~a~%") name version) (leave (_ "~A: unknown package~%") name)))))) + +(define* (specification->package+output spec #:optional (output "out")) + "Return the package and output specified by SPEC, or #f and #f; SPEC may +optionally contain a version number and an output name, as in these examples: + + guile + guile-2.0.9 + guile:debug + guile-2.0.9:debug + +If SPEC does not specify a version number, return the preferred newest +version; if SPEC does not specify an output, return OUTPUT." + (define (ensure-output p sub-drv) + (if (member sub-drv (package-outputs p)) + sub-drv + (leave (_ "package `~a' lacks output `~a'~%") + (package-full-name p) + sub-drv))) + + (let-values (((name version sub-drv) + (package-specification->name+version+output spec output))) + (match (find-best-packages-by-name name version) + ((p) + (values p (ensure-output p sub-drv))) + ((p p* ...) + (warning (_ "ambiguous package specification `~a'~%") + spec) + (warning (_ "choosing ~a from ~a~%") + (package-full-name p) + (location->string (package-location p))) + (values p (ensure-output p sub-drv))) + (() + (leave (_ "~a: package not found~%") spec))))) |