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stylewarning
computable-reals
Common Lisp2019–2024
stylewarning / computable-reals

computable-reals

Arbitrary precision, automatic re-computing real numbers in Common Lisp.

2Distinct people
2Mentions
0Explicit recommenders
36GitHub stars
REPOSITORY AT A GLANCE

What to know before exploring

What it is

Arbitrary precision, automatic re-computing real numbers in Common Lisp.

GitHub

Where it is used

No documented product use has been verified yet.

What people are saying

No recommendation phrase was found in the indexed comments.

No classified warning is attached to this page. Read the discussions before treating silence as approval.

Also in these discussions

No other repository is repeatedly linked in the same discussions.

This week on Hacker News

Nov 7–Nov 14 UTC · Direct repository links and separately labeled related project stories. Indexed through 11/14/2026, 3:03:16 PM UTC.

No direct repository links were found in the indexed HN discussions over the past seven days. Older discussions are available below.

Mentions over time

HN mentions by year2 dated mentions

Observed mentions: 2019-06-14 15:53:10 UTC to 2024-06-11 19:15:40 UTC.

012019-01-01 00:00:00 UTC to 2020-01-01 00:00:00 UTC (exclusive): 1 mentions; 0 submissions, 1 comments20192020-01-01 00:00:00 UTC to 2021-01-01 00:00:00 UTC (exclusive): 0 mentions; 0 submissions, 0 comments2021-01-01 00:00:00 UTC to 2022-01-01 00:00:00 UTC (exclusive): 0 mentions; 0 submissions, 0 comments20212022-01-01 00:00:00 UTC to 2023-01-01 00:00:00 UTC (exclusive): 0 mentions; 0 submissions, 0 comments2023-01-01 00:00:00 UTC to 2024-01-01 00:00:00 UTC (exclusive): 0 mentions; 0 submissions, 0 comments2024-01-01 00:00:00 UTC to 2025-01-01 00:00:00 UTC (exclusive): 1 mentions; 0 submissions, 1 comments2024

Counts come from the repository’s dated source evidence. Index cutoff: 2026-11-02 08:16:59 UTC.

View mention counts and date ranges
UTC ranges include their start and exclude their end. Select a period to filter the source evidence.
PeriodStart (UTC)End (exclusive, UTC)MentionsSubmissionsComments
20192019-01-01 00:00:00 UTC2020-01-01 00:00:00 UTC101
20202020-01-01 00:00:00 UTC2021-01-01 00:00:00 UTC000
20212021-01-01 00:00:00 UTC2022-01-01 00:00:00 UTC000
20222022-01-01 00:00:00 UTC2023-01-01 00:00:00 UTC000
20232023-01-01 00:00:00 UTC2024-01-01 00:00:00 UTC000
20242024-01-01 00:00:00 UTC2025-01-01 00:00:00 UTC101

What Hacker News says

2 sources
The precision argument is so amazingly bogus that I won't refute it except with a link[1], so here are refutations of some other parts: > My kids sometimes ask me how high I can count. I’ve noticed that they stop asking this question once they reach a certain age, usually around six or seven. This is because the question does not make sense once you understand what a number is. If there’s a single highest number you can count to, you don’t really grok numbers. The difference between computers and humans doing math is a bit like the difference between the younger kids who think that “how high you can count” is a real thing and the older kids who have successfully understood how numbers work. There actually is an answer to this; most people's short term memory for digits is less than a dozen, so the author likely can't count higher than 1e1
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2, as they won't be able to go from e.g. 374841483741 to 374841483742 without getting one of the digits in the middle wrong. > The representation of the numbers that occurs only in the mind of the human is conflated with the execution of a particular program that takes place in the computer This merely argues that computer math can be different than human math, which even that I'm not quite going to concede, since it would imply e.g. that the mathematicians behind the IEEE 754 standard were unaware of the implications of floating point arithmetic. > To us the transition between the theoretical and the actual happens almost instantly and unnoticeably. Indeed it is happening almost instantly and (being generous to the author) without the author noticing throughout this paper, conflating concepts to the point where one could demonstrate almost anything is beyond the reach of computers, even things that are clearly well within the reach of them! 1: https://github.com/stylewarning/computable-reals
In Computers Can't Do Math
The COMPUTABLE-REALS [0] package from the article is interesting because it lets you change the precision even after a computation is “performed”. It basically builds up lazy representations of computations that can (internally) recompute to any precision specified. You do all of your arithmetic as normal and only until you need to do something with an actual decimal representation do you “request” it. You grab the actual approximation as a decimal number with the APPROX-R function, which provides as many digits as you please. There is no need to re-run all of your code which produced the (computable) number in the first place to reapproximate at higher precision. This all directly falls out of a mathematical formalism called “computable real numbers” [1] which are the (countable!) set of real numbers for which an algorithm exists to comp
Read the rest
ute the digits to any desired precision. (Usually binary digits are the standard way to write out the definition of a computable number.) [0] https://github.com/stylewarning/computable-reals [1] https://en.m.wikipedia.org/wiki/Computable_number
In Common Lisp: Numbers

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