I often do this without even thinking about it -- I'll start a new program by writing a working prototype, but I won't even run it through the parser until I fe

I often do this without even thinking about it -- I'll start a new program by writing a working prototype, but I won't even run it through the parser until I feel that it is minimally complete and have "proven it correct". It lets me focus on writing and thinking instead of editing and the 'trivial' matter of whether it works at all. Then I spend some time fixing stupid syntax errors and namespace collisions so it parses and works, init version control, and after that I do super-short iterations.