trace.clj: add dotrace; fixes #39

Patch from Michel Salim

2 files changed, 19 insertions, 2 deletions

diff --git a/src/clojure/contrib/test_contrib/test_trace.clj b/src/clojure/contrib/test_contrib/test_trace.clj
index 4b283056..dee7122a 100644
--- a/src/clojure/contrib/test_contrib/test_trace.clj
+++ b/src/clojure/contrib/test_contrib/test_trace.clj
@@ -9,4 +9,8 @@
 (deftest test-tracing-a-function-that-calls-itself
   (let [output (with-out-str (call-myself 1))]
     (is (re-find #"^TRACE t\d+: (call-myself 1)\nTRACE t\d+: |    (call-myself 0)\nTRACE t\d+: |    => nil\nTRACE t\d+: => nil$"
-                 output))))
\ No newline at end of file
+                 output))))
+
+(deftest dotrace-on-core
+  (let [output (with-out-str (dotrace [mod] (mod 11 5)))]
+    (is (re-find #"\(mod 11 5\)" output))))
diff --git a/src/clojure/contrib/trace.clj b/src/clojure/contrib/trace.clj
index 1ac00a70..ccfc5ef1 100644
--- a/src/clojure/contrib/trace.clj
+++ b/src/clojure/contrib/trace.clj
@@ -32,7 +32,7 @@
 
 
 (ns 
-  #^{:author "Stuart Sierra",
+  #^{:author "Stuart Sierra, Michel Salim",
      :doc "This file defines simple \"tracing\" macros to help you see what your
 code is doing."}
   clojure.contrib.trace)
@@ -83,3 +83,16 @@ code is doing."}
        (defn ~name [& args#]
          (trace-fn-call '~name f# args#)))))
 
+(defmacro dotrace
+  "Given a sequence of function identifiers, evaluate the body
+   expressions in an environment in which the identifiers are bound to
+   the traced functions.  Does not work on inlined functions,
+   such as clojure.core/+"
+  [fns & exprs]
+  (if (empty? fns)
+    `(do ~@exprs)
+    (let [func  (first fns)
+          fns (next fns)]
+      `(let [f# ~func]
+         (binding [~func (fn [& args#] (trace-fn-call '~func f# args#))]
+           (dotrace ~fns ~@exprs))))))