Re:The hardest program I've ever written (2015)
by lakecresva on Saturday March 05, 2022 @06:16PM
(#30572975)
I also wrote a version of Bernardy's pretty printer, but I never did come up with a satisfactory way of formatting text together with code. The best looking solution of splitting on whitespace and making each word a group, either tacking it onto the current line or splitting onto a new line ends up being exponential even with pretty aggressive optimization. Everything else I tried looked bad.
https://jyp.github.io/pdf/Prettiest.pdf
It's based on introducing choice between vertical and horizontal stacking. It avoids combinatorial explosion by pruning away strictly suboptimal choices. With just a few extra rules for Lisp forms, the results are quite good.
I don't handle comments though, since I only need it for pretty printing values so far.