/tracer

trace clojure call stack

Primary LanguageClojure

tracer

trace clojure call stack.

When I read some open source clojure source code, I find that some function/logic are so complex that it is not so easy to understand it, so I think it will help me a lot if I can see the actual function call stack with the provided paremeters, so I developed this simple tool to facilitate reading of clojure source code.

Usage

  • Add the following into your ~/.lein/profiles.clj:
{:user {
        :dependencies [[tracer "1.0.0-SNAPSHOT"]]
        :repl-options {:init (use 'tracer.core)}}}

This will make tracer automatically available when repl is loaded. The only two functions you will be interested in is trace and untrace.

  • Tell tracer which namespace you want to trace:
;; CHANGE 'blind.reader TO YOUR OWN namespace
(trace 'blind.reader)
  • Invoke your function to see what happens( you get a call tree & with the parameter value! ):
|- (blind.reader/read-string "\"hello\"")
| |- (blind.reader/string-push-back-reader "\"hello\"")
| | |- (blind.reader/string-push-back-reader "\"hello\"" 1)
| | | |- (blind.reader/string-reader "\"hello\"")
| | |  \=> blind.reader.StringReader@36a3bb2e
| |  \=> blind.reader.PushbackReader@682f8c99
|  \=> blind.reader.PushbackReader@682f8c99
| |- (blind.reader/read #<PushbackReader blind.reader.PushbackReader@682f8c99> true nil false)
| | |- (blind.reader/char \")
| |  \=> "
| | |- (blind.reader/whitespace? \")
| |  \=> false
| | |- (blind.reader/number-literal? #<PushbackReader blind.reader.PushbackReader@682f8c99> \")
| | | |- (blind.reader/numeric? \")
| | |  \=> false
| |  \=> false
| | |- (blind.reader/comment-prefix? \")
| |  \=> false
| | |- (blind.reader/macros \")
| |  \=> tracer.core$trace$fn__931$fn__932@72dd23cf
| | |- (blind.reader/read-string* #<PushbackReader blind.reader.PushbackReader@682f8c99> \")
| | | |- (blind.reader/char \h)
| | |  \=> h
| | | |- (blind.reader/char \e)
| | |  \=> e
| | | |- (blind.reader/char \l)
| | |  \=> l
| | | |- (blind.reader/char \l)
| | |  \=> l
| | | |- (blind.reader/char \o)
| | |  \=> o
| | | |- (blind.reader/char \")
| | |  \=> "
| |  \=> hello
|  \=> hello
 \=> hello
"hello"

  • Finally, you can undo all the tracing by calling untrace with the same namespace symbol.

  • If you want to see the thread id which the functions has been called, you can add an :show-tid flag when calling trace.

user=>(trace 'user :show-tid)
user=>(foo 5)
18: |-+ (user/foo 5)
18: | |-+ (user/bar 5)

Features

  • You can get a colorized call stack tree if you pass :with-color to trace.
  • Make private function public, so you can call it easily in REPL.

Contributors

License

Copyright (C) 2013 xumingming

Distributed under the Eclipse Public License, the same as Clojure.