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| author | Ludovic Courtès <ludo@gnu.org> | 2016-05-23 23:03:23 +0200 |
|---|---|---|
| committer | Ludovic Courtès <ludo@gnu.org> | 2016-05-24 00:06:01 +0200 |
| commit | e144e3427da93b962c7620ce2bd64add8c83cfdc (patch) | |
| tree | 2f1cd6dd65e764e8dab09d5fa97f86a62664617d /guix/graph.scm | |
| parent | 623e4df42abd024e0a62ef0b30f9b550f37cba57 (diff) | |
| download | gnu-guix-e144e3427da93b962c7620ce2bd64add8c83cfdc.tar gnu-guix-e144e3427da93b962c7620ce2bd64add8c83cfdc.tar.gz | |
graph: Add 'node-reachable-count'.
* guix/graph.scm (node-reachable-count): New procedure.
* tests/graph.scm ("node-reachable-count"): New test.
Diffstat (limited to 'guix/graph.scm')
| -rw-r--r-- | guix/graph.scm | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/guix/graph.scm b/guix/graph.scm index af589c5c67..735d340c2c 100644 --- a/guix/graph.scm +++ b/guix/graph.scm @@ -39,6 +39,7 @@ node-back-edges traverse/depth-first node-transitive-edges + node-reachable-count %graphviz-backend graph-backend? @@ -126,6 +127,13 @@ procedure that, given a node, returns its list of direct dependents; it is typically returned by 'node-edges' or 'node-back-edges'." (traverse/depth-first cons '() nodes node-edges)) +(define (node-reachable-count nodes node-edges) + "Return the number of nodes reachable from NODES along NODE-EDGES." + (traverse/depth-first (lambda (_ count) + (+ 1 count)) + 0 + nodes node-edges)) + ;;; ;;; Graphviz export. |