diff options
| -rw-r--r-- | doc/guix.texi | 24 | ||||
| -rw-r--r-- | guix/packages.scm | 34 |
2 files changed, 58 insertions, 0 deletions
diff --git a/doc/guix.texi b/doc/guix.texi index 32bfd29dbe..9cb7ac53f9 100644 --- a/doc/guix.texi +++ b/doc/guix.texi @@ -6817,6 +6817,30 @@ cross-compiling: It is an error to refer to @code{this-package} outside a package definition. @end deffn +The following helper procedures are provided to help deal with package +inputs. + +@deffn {Scheme Procedure} lookup-package-input @var{package} @var{name} +@deffnx {Scheme Procedure} lookup-package-native-input @var{package} @var{name} +@deffnx {Scheme Procedure} lookup-package-propagated-input @var{package} @var{name} +@deffnx {Scheme Procedure} lookup-package-direct-input @var{package} @var{name} +Look up @var{name} among @var{package}'s inputs (or native, propagated, +or direct inputs). Return it if found, @code{#f} otherwise. + +@var{name} is the name of a package depended on. Here's how you might +use it: + +@lisp +(use-modules (guix packages) (gnu packages base)) + +(lookup-package-direct-input coreutils "gmp") +@result{} #<package gmp@@6.2.1 @dots{}> +@end lisp + +In this example we obtain the @code{gmp} package that is among the +direct inputs of @code{coreutils}. +@end deffn + Because packages are regular Scheme objects that capture a complete dependency graph and associated build procedures, it is often useful to write procedures that take a package and return a modified version diff --git a/guix/packages.scm b/guix/packages.scm index 37814c2f63..ac5ff5a51b 100644 --- a/guix/packages.scm +++ b/guix/packages.scm @@ -108,6 +108,11 @@ deprecated-package package-field-location + lookup-package-input + lookup-package-native-input + lookup-package-propagated-input + lookup-package-direct-input + package-direct-sources package-transitive-sources package-direct-inputs @@ -889,6 +894,35 @@ preserved, and only duplicate propagated inputs are removed." ((input rest ...) (loop rest (cons input result) propagated first? seen))))) +(define (lookup-input inputs name) + "Lookup NAME among INPUTS, an input list." + ;; Note: Currently INPUTS is assumed to be an input list that contains input + ;; labels. In the future, input labels will be gone and this procedure will + ;; check package names. + (match (assoc-ref inputs name) + ((obj) obj) + ((obj _) obj) + (#f #f))) + +(define (lookup-package-input package name) + "Look up NAME among PACKAGE's inputs. Return it if found, #f otherwise." + (lookup-input (package-inputs package) name)) + +(define (lookup-package-native-input package name) + "Look up NAME among PACKAGE's native inputs. Return it if found, #f +otherwise." + (lookup-input (package-native-inputs package) name)) + +(define (lookup-package-propagated-input package name) + "Look up NAME among PACKAGE's propagated inputs. Return it if found, #f +otherwise." + (lookup-input (package-propagated-inputs package) name)) + +(define (lookup-package-direct-input package name) + "Look up NAME among PACKAGE's direct inputs. Return it if found, #f +otherwise." + (lookup-input (package-direct-inputs package) name)) + (define (package-direct-sources package) "Return all source origins associated with PACKAGE; including origins in PACKAGE's inputs." |