“Pulling a New Proof from Knuth's Fixed-Point Printer”

[rsc@hachyderm.io]

“Pulling a New Proof from Knuth's Fixed-Point Printer”

Happy 88th Birthday to Don Knuth!

And thanks again to Rob Pike for Ivy.

https://research.swtch.com/fp-knuth

[svat@mathstodon.xyz]

@rsc Nice post! I hope to reread it carefully, but in the meantime: I don't know if you've seen this, but when this paper was reprinted in *Selected Papers on Design of Algorithms* (as Chapter 11), it comes with the following:

> Addendum

> Formal developments of program P2 were subsequently presented by David Gries ("Binary to decimal, one more time," in Beauty Is Our Business (New York: Springer-Verlag, 1990), 141-148; by R. S. Bird ["Functional pearls: Two greedy algorithms," Journal of Functional Programming 2 (1992), 237-244]; and by Jinyun Xue and Ruth Davis ("A derivation and proof of Knuth's binary to decimal conversion program," Software — Concepts and Tools 18 (1997), 149-156).

> For general procedures that convert accurately between floating-point binary and floating-point decimal numbers according to IEEE standard conventions, see Donald E. Knuth, MMIXware: A RISC Computer for the Third Millennium, Lecture Notes in Computer Science 1750 (Berlin: Springer-Verlag, 1999), 86-100.

[rsc@hachyderm.io]

@svat Fascinating, thank you for the links. I have both books but I've been working from the "Beauty is Our Business" copy because it arrived first and it stays open better on my desk. 😀

I will definitely look those up. Thanks again!

[dougmerritt@mathstodon.xyz]

@rsc
In your article, the link to Ivy gives a 404 error. The problem is that it contains an extraneous ".io": "robpike.io".

Poking around, the following does work:
https://github.com/robpike/ivy