diff options
Diffstat (limited to 'guix/store.scm')
| -rw-r--r-- | guix/store.scm | 26 |
1 files changed, 26 insertions, 0 deletions
diff --git a/guix/store.scm b/guix/store.scm index d15ba1275f..57e1ca06aa 100644 --- a/guix/store.scm +++ b/guix/store.scm @@ -31,6 +31,7 @@ #:use-module (srfi srfi-39) #:use-module (ice-9 match) #:use-module (ice-9 regex) + #:use-module (ice-9 vlist) #:export (%daemon-socket-file nix-server? @@ -70,6 +71,7 @@ substitutable-path-info references + requisites referrers valid-derivers query-derivation-outputs @@ -493,6 +495,30 @@ file name. Return #t on success." "Return the list of references of PATH." store-path-list)) +(define* (fold-path store proc seed path + #:optional (relatives (cut references store <>))) + "Call PROC for each of the RELATIVES of PATH, exactly once, and return the +result formed from the successive calls to PROC, the first of which is passed +SEED." + (let loop ((paths (list path)) + (result seed) + (seen vlist-null)) + (match paths + ((path rest ...) + (if (vhash-assoc path seen) + (loop rest result seen) + (let ((seen (vhash-cons path #t seen)) + (rest (append rest (relatives path))) + (result (proc path result))) + (loop rest result seen)))) + (() + result)))) + +(define (requisites store path) + "Return the requisites of PATH, including PATH---i.e., its closure (all its +references, recursively)." + (fold-path store cons '() path)) + (define referrers (operation (query-referrers (store-path path)) "Return the list of path that refer to PATH." |