From ba326ce41b5784f3acb99d4beae5ffc455d6a27e Mon Sep 17 00:00:00 2001 From: Ludovic Courtès Date: Mon, 19 Nov 2012 22:37:50 +0100 Subject: distro: Add `fold-packages'. * distro.scm (fold-packages): New procedure. (find-packages-by-name): Use it instead of hand-written traversal; remove `package?' checks from `right-package?'. * tests/packages.scm ("fold-packages"): New test. --- distro.scm | 35 ++++++++++++++++++++++++----------- 1 file changed, 24 insertions(+), 11 deletions(-) (limited to 'distro.scm') diff --git a/distro.scm b/distro.scm index bbfe51c943..2d441f450b 100644 --- a/distro.scm +++ b/distro.scm @@ -26,6 +26,7 @@ #:export (search-patch search-bootstrap-binary %patch-directory + fold-packages find-packages-by-name)) ;;; Commentary: @@ -105,22 +106,34 @@ (false-if-exception (resolve-interface name)))) (package-files))) +(define (fold-packages proc init) + "Call (PROC PACKAGE RESULT) for each available package, using INIT as +the initial value of RESULT." + (fold (lambda (module result) + (fold (lambda (var result) + (if (package? var) + (proc var result) + result)) + result + (module-map (lambda (sym var) + (false-if-exception (variable-ref var))) + module))) + init + (package-modules))) + (define* (find-packages-by-name name #:optional version) "Return the list of packages with the given NAME. If VERSION is not #f, then only return packages whose version is equal to VERSION." (define right-package? (if version (lambda (p) - (and (package? p) - (string=? (package-name p) name) + (and (string=? (package-name p) name) (string=? (package-version p) version))) (lambda (p) - (and (package? p) - (string=? (package-name p) name))))) - - (append-map (lambda (module) - (filter right-package? - (module-map (lambda (sym var) - (variable-ref var)) - module))) - (package-modules))) + (string=? (package-name p) name)))) + + (fold-packages (lambda (package result) + (if (right-package? package) + (cons package result) + result)) + '())) -- cgit v1.2.3