I just completed the 2012 State of Clojure survey and it got me thinking about how to fairly judge languages like Clojure. We need new software metrics. Performance is easy to quantify: write a program, run it a lot, and measure the time it took. Do that across multiple languages, and you can find a winner (the one offering the most operations per time). For example, check Debian’s Language Shootout where Fortran and C rule. However, solely measuring performance misses a bigger (in my opinion) problem: development speed and ease-of-use. In my limited experience, Clojure is significantly shorter and easier to reason about that equivalent C projects. To be fair, it’s been a while since I wrote much in C, but Clojure has also been easier to understand and change than Java code. In addition, Clojure programs are (basically) concurrent out-of-the-box. I think concurrency is generally very difficult and error-prone; however, concurrency is increasingly necessary—making Clojure that much stronger. But none of that is captured in common metrics.
With the availability of lots of developers online I think we could tackle harder to quantify metrics like
- performance per line of code
- performance per development time
- performance per noob minute
- comprehensibility per time
- time to change a line of code
The first pass on how to achieve this (tons of issues, no doubt): survey all the developers you can find. Collect all the information you can through the survey and GitHub tie-ins then ask people to perform tasks like explaining a piece of code and writing/changing programs across languages. An automated approach might start by finding a series of program solutions (from a set like 99 Bottles of Beer, Project Euler, Rosetta Code, or 99 Problems in X), then gather data about each solution and people’s feelings about each. Maybe you could seed a bug and see how long it takes people to find and fix the bug.
Have I missed better software metrics? What metrics define a language you want to write in? How can we accurately collect those metrics?