I wish there was a desktop app that allowed me to draw diagrams in "vector" ascii art that I could then process with `dia` or another similar program to produce images.
https://metacpan.org/pod/App::Asciio
As it's not completely obvious, Asciio will save to plain text if you simply use the .txt extension, and else its own binary editable format.
Asciio is present in Debian/Ubuntu repositories.
Here's a demo: http://ivanceras.github.io/svgbob-editor/
Edit: nevermind, misunderstood; this isn't what you're looking for.