[pgt]

This is a good idea. I recently wrote down some ideas about "How to Grow a Program," in a symbolic programming environment: https://github.com/theronic/hoist/

I call it Hoist - from "hoisting up" concrete, hard-coded values into abstract symbols for reuse. It's complete vaporware at this point, just a place to collect my thoughts for a future essay.

[teddyh]

See also: In TDD, there are defined steps you go through as you gradually refine your code to actually do more and more things; from returning nothing, to returning one value, to returning a list, etc.