This program is a command line tool to calculate complexity metrics using the indentation of the source code as a proxy for complexity. The program reads code from either a file or from stdin (it's designed to work together with the rest of the command line world).
The idea of using indentation as a proxy for complexity is backed by research. It's a simple metric, yet it correlates medium to high with more elaborate metrics such as McCabe Cyclomatic Complexity and Halstead complexity measures.
I don't use indentation-based complexity as a replacement. Rather, I see its advantage in the following situations:
- Language independent: no need for a separate parser for each programming language in polyglot code bases.
- Calculates incomplete code: perfect for code snippets or partial code.
- Speed: indentation is a simple and fast metric that quickly hints at the underlaying complexity.
Of course, some constructs are indeed non-trivial despite their flat indentation (list comprehensions come to mind). But again, measuring software complexity from a static snapshot of the code is unlikely to ever produce adequate metrics; it's a hint at best.
I'm not hosting any pre-built binaries. The tool is written in Clojure. To build it from source, use leiningen:
lein uberjar
The command above will create a standalone jar containing all the dependencies (you'll probably want to wrap the execution in a shell script).
The tool outputs the total, aggregated complexity of the provided code together with some basic statistics (mean, median, standard deviation, etc). Empty and blank lines are ignored.
Just provide the file as an argument:
adam$ java -jar indent-complexity-proxy-0.2.0-standalone.jar project.clj
{:total 19.5, :n 12, :mean 1.63, :median 0.50, :sd 1.79, :max 9/2}
If you want a quick summary of the total complexity, add the -c switch:
adam$ java -jar indent-complexity-proxy-0.2.0-standalone.jar project.clj -c
19.5
The tool accepts input on standard input. Just pipe some code to it:
adam$ cat project.clj | java -jar target/indent-complexity-proxy-0.2.0-standalone.jar
{:total 19.5, :n 12, :mean 1.63, :median 0.50, :sd 1.79, :max 9/2}
Run the tool with the -h option to get a list of supported arguments:
adam$ java -jar target/indent-complexity-proxy-0.2.0-standalone.jar -h
This program calculates code complexity using white space as a proxy.
Usage: program-name [options] file|stdin
Options:
-s, --spaces SPACES 4 The number of spaces to consider one logical indent.
-t, --tabs TABS 1 The number of tabs to consider one logical indent.
-c, --complexity Just output the total complexity.
-h, --help