diff options
| -rw-r--r-- | src/clj/clojure/core.clj | 30 |
1 files changed, 13 insertions, 17 deletions
diff --git a/src/clj/clojure/core.clj b/src/clj/clojure/core.clj index 8d4d863d..5c012155 100644 --- a/src/clj/clojure/core.clj +++ b/src/clj/clojure/core.clj @@ -2824,23 +2824,19 @@ `(print-namespace-doc ~nspace) `(print-doc (var ~name)))))) -(defn tree-seq - "returns a lazy sequence of the nodes in a tree, via a depth-first walk. - branch? must be a fn of one arg that returns true if passed a node - that can have children (but may not). children must be a fn of one - arg that returns a sequence of the children. Will only be called on - nodes for which branch? returns true. Root is the root node of the - tree, must be a branch." - [branch? children root] - (let [walk (fn walk [nodes] - (when-first [node nodes] - (lazy-cons - node - (if (branch? node) - (lazy-cat (walk (children node)) - (walk (rest nodes))) - (walk (rest nodes))))))] - (lazy-cons root (walk (children root))))) + (defn tree-seq + "Returns a lazy sequence of the nodes in a tree, via a depth-first walk. + branch? must be a fn of one arg that returns true if passed a node + that can have children (but may not). children must be a fn of one + arg that returns a sequence of the children. Will only be called on + nodes for which branch? returns true. Root is the root node of the + tree." + [branch? children root] + (let [walk (fn walk [node] + (lazy-cons node + (when (branch? node) + (mapcat walk (children node)))))] + (walk root))) (defn file-seq "A tree seq on java.io.Files" |