The folks at the Viewpoints Research Institute created a DSL to describe the TCP/IP stack using an ASCII diagram: http://www.moserware.com/2008/04/towards-moores-law-software... Befunge is also a sort of control flow diagram: http://en.wikipedia.org/wiki/Befunge

Check out Funciton (http://esolangs.org/wiki/Funciton) - an esoteric programming language that is based on a similar idea.

Sigvehtml[1] kind of does this (disclaimer: I made it).

[1]: https://github.com/sigvef/sigvehtml

Sounds cumbersome.

I guess it would be cumbersome in a standard editor, maybe an ide which had function to create new methods and classes would be needed. also the added benefit is that the code could serve as a diagram of itself.

But if you're going to use an IDE to generate all the ASCII, why not just use regular graphics instead?

I guess because then you can view it in any editor later. Or view it in a simple terminal.