Varspotting

Spotting Clojure Vars for fun and profit!

Inspired by the Roughly how many functions are in the Clojure core libraries? Stack Overflow question.

Usage

Varspotting reports counts of Clojure Vars meeting certain criteria.

Here's the default report on built-in Clojure Vars (for Clojure 1.5.1):

Varspotting report for clojure.core:
====================================

|                  Spotter | Var count |
|--------------------------+-----------|
|                   Public |       591 |
|                  Unbound |         2 |
|                  Dynamic |        11 |
|         Proper functions |       475 |
|                   Macros |        76 |
|              Non-fn IFns |         6 |
| Dynamic proper functions |         1 |

Varspotting report for built-in namespaces:
===========================================

|                  Spotter | Var count |
|--------------------------+-----------|
|                   Public |       844 |
|                  Unbound |         6 |
|                  Dynamic |        39 |
|         Proper functions |       670 |
|                   Macros |        99 |
|              Non-fn IFns |        17 |
| Dynamic proper functions |         6 |

Varspotting can be used as a library or a Leiningen plugin. The Leiningen dependency specifier is

[varspotting "0.0.2"]

Including this dependency in the :user profile will make Varspotting available in all Leiningen projects:

;; in ~/.lein/profiles.clj
{:user {:plugins [[varspotting "0.0.2"]]}}

Note that Varspotting currently has no dependencies besides Clojure.

With the above profiles.clj entry in place, the following will print the default report for Clojure namespaces specified above:

lein varspotting

Alternatively, you can say

lein varspotting <namespaces-to-report-on>

to get a report on the specified namespaces. In this way, Varspotting can be used to report on arbitrary Clojure libraries. Here's the default report on Varspotting 0.0.2:

Varspotting report for varspotting.core, leiningen.varspotting:
===============================================================

|                  Spotter | Var count |
|--------------------------+-----------|
|                   Public |        23 |
|                  Unbound |         0 |
|                  Dynamic |         1 |
|         Proper functions |        17 |
|                   Macros |         4 |
|              Non-fn IFns |         2 |
| Dynamic proper functions |         0 |

The varspotting.core namespace includes docstrings describing all the building blocks behind the final report. Of particular interest are the spotter, defspotter and print-spotting-report macros and the *spotters* dynamically-rebindable Var; these can be used to prepare custom reports. For now, to use custom spotters alongside the full suite of built-in spotters, one can use

(with-default-spotters
  (binding [*spotters* (into *spotters* custom-spotters)]
    (print-spotting-report namespaces
      ...)))

See leiningen.varspotting for the actual function handling user interaction.

Licence

Copyright © 2013 Michał Marczyk

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