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A library for creating more readable stacktraces in Clojure programs.

For example, to print a nice stack trace in a REPL:

=> (use 'clj-stacktrace.repl)
=> ("foo")
java.lang.ClassCastException: java.lang.String cannot be cast to clojure.lang.IFn (NO_SOURCE_FILE:0) clojure.lang.Compiler.eval clojure.lang.Compiler.eval
            core.clj:2382 clojure.core/eval
             main.clj:183 clojure.main/repl[fn]
             main.clj:204 clojure.main/repl[fn]
             main.clj:204 clojure.main/repl
             main.clj:262 clojure.main/repl-opt
             main.clj:355 clojure.main/main
Caused by: java.lang.String cannot be cast to clojure.lang.IFn
         NO_SOURCE_FILE:2 user/eval100 clojure.lang.Compiler.eval

In stack traces printed by pst:

  • Java methods are described with the usual convention and Clojure functions with their own convention.
  • Anonymous clojure functions are denoted by adding an [fn] to their enclosing, named function.
  • "Caused by" cascades are shown as in regular java stack traces.
  • Elements are vertically aligned for better readability.
  • Printing is directed to *out*.

If you want to direct the printing to somewhere other than *out*, either use pst-on to specify the output location or pst-str to capture the printing as a string.

The library also offers an API for programatically 'parsing' exceptions. This API is used internal for pst and can be used to e.g. improve development tools. Try for example:

=> (use '(clj-stacktrace core))
=> (try
     (catch Exception e
       (parse-exception e)))


Copyright 2009-2010 Mark McGranaghan and released under an MIT license.

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