Talk:Substring primes

different than truncatable primes?

How does this differ from truncatable primes?--Nigel Galloway (talk) 15:07, 5 April 2021 (UTC)

It's a smaller list,   it includes substrings that are not truncatable.     -- Gerard Schildberger (talk) 15:39, 5 April 2021 (UTC)

See the OEIS entry:   A024770.

See the OEIS entry:   A024785.

See the OEIS entry:   A085823.

limit

Removed utterly pointless limit of 500. Find 'em all, it's the same output, and encourages a little more thought than for i=1 to 500. --Pete Lomax (talk) 08:54, 6 April 2021 (UTC)

By removing the task's limit, you're invalided all but "your" solution.   The whole point of Rosetta Code   (well, at least one of them)   is to compare how different computer programming languages (and programmers) solve the stated problem (the task as stated).   Significantly changing the (draft) task's requirements (and/or wording) makes comparing the solutions at this point, pointless.   At this time, all but one programming solution uses a limit of some kind.     -- Gerard Schildberger (talk) 10:26, 6 April 2021 (UTC)

They are not invalid at all, they all give the correct output, apart from the REXX entry which blatently lies about how many prime tests it performs (it's 26 btw, or 119 if you also count the digit-wise exclusions). Using a limit is a valid way to do it, just not a very smart one. I was only trying to make a rather pedestrian task into something slightly more interesting/challenging, optionally. If you want to change it to something like "This can be achieved by filtering all primes below 500 (there are 95 of them), but it can also be done by only checking 15 numbers." then I'll not complain. --Pete Lomax (talk) 13:34, 6 April 2021 (UTC)

The REXX entry does give the correct output.   Apart from your characterization of how (and what) the REXX entry counts as primality testing,   and I   (as the sole author of the REXX entry)   shouldn't be accused of being blatantly lying;   I didn't considering the elimination of various numbers using digit-wise filtering as a primality test,   but I don't want to get into useless and/or pejorative arguments about how one   counts   the number of primality tests and whether or not it was performed in a blatant manner (or not).   I added the primality counting in good faith and I don't see how you could label that as lying,   and blatant lying at that.   And, no, I do not want to change the task's requirements as per your suggesting such that you won't complain.   That's not how changing of someone else's Rosetta Code task's requirements is supposed to work.   Furthermore, please be more careful of calling people liars on Rosetta Code.     -- Gerard Schildberger (talk) 20:31, 6 April 2021 (UTC)

My apologies, the 119 was a step too far. I ran your code on tio and it displayed 26 rather than the 14 claimed in the output. I will admit that I do not know enough about the REXX programming language to understand why that might not be classified as blatent lying. I will not however apologise for nor promise to desist in making what I think are sensible proactive changes to tasks shortly after creation, particularly not when a task is utterly trivial and extremely similar to a very recent one. There is always the undo button but you are not interested in that. Ultimately I simply do not understand why you complain about such changes but not about the creation of the task in the first place. There are many tasks on RC that I wish somone else would spot a way to improve or make more challenging and interesting. If I have to revisit my code, that should be and usually is a good thing. --Pete Lomax (talk) 08:08, 7 April 2021 (UTC)