added letfn, supports mutually recursive local fns

1 files changed, 11 insertions, 0 deletions

diff --git a/src/clj/clojure/core.clj b/src/clj/clojure/core.clj
index 1b54f5e5..90566791 100644
--- a/src/clj/clojure/core.clj
+++ b/src/clj/clojure/core.clj
@@ -4047,3 +4047,14 @@
   evaluated in parallel" 
   [& exprs]
   `(pcalls ~@(map #(list `fn [] %) exprs)))
+
+(defmacro letfn 
+  "Takes a vector of function specs and a body, and generates a set of
+  bindings of functions to their names. All of the names are available
+  in all of the definitions of the functions, as well as the body.
+
+  fnspec ==> (fname [params*] exprs) or (fname ([params*] exprs)+)" 
+  [fnspecs & body] 
+  `(letfn* ~(vec (interleave (map first fnspecs) 
+                             (map #(cons `fn* %) fnspecs)))
+           ~@body))