bug-apl
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 Hi, the scalar extension mechanism is a very fundamental principle which existed since the beginning of APL. If you randomly pick an 1-element value from any APL program, then I would bet that the value is a scalar with a probability of ≥ 90%, and a matrix or higher rank value with a probability of ≤ 1%. There have been studies about this in the 1980s. Therefore taking a 1-element item as a scalar is simply the most pragmatic choice. /// Jürgen On 03/03/2017 10:57 PM, address@hidden wrote: ```On Fri, 3 Mar 2017 20:45:45 +0100 Juergen Sauermann wrote: ``` ```Hi, ``` ```what is the reason? do you know their reasoning cause 1 is 1 element and 1 2 3 is 3 elements so ⍴ 1 2 3 is 3 and ⍴ 1 should have been 1 I never understood their reasoning or how it negatively affected anything else - it must have been in the implementation that they had couldn't apply vector/array code to just one element so they did it this way i think like the char type vs array type but you can have an array of 1 element (in c and fpc anyway) ``` ```I believe the reason why 'a' is scalar and 'abc' is not is the same as why 1 is a scalar and 1 2 3 is not. It is very consistent, but often very inconvenient. And in practice it is often a pitfall for the unaware programmer. I fooled myself a couple of times and then decided to introduce "a" which avoids the problems with 'a'. Before "a" you had to (,'a') or ,'a' if circumstances allowed (introducing other traps, of course). /// Jürgen On 03/03/2017 06:57 PM, address@hidden wrote: thank you - fantastic ...it sure 'fixes' the inconsistency i had no idea about "a" I saw the use of " only in the FILE_IO "r" in the apl.html but thought that was related to just fopen/bash/c syntax --- Do you know the 'details' about why iverson did this to begin with? How did you deal with scalar 'a' before the "a" in gnuap? didn't you have 'wasted code' to deal with the following to deal with scalar 'a' ⍴'a' ''=⍴'a' ⍴⍴'a' 0 --- the video in case you hadn't seen it # APL 1991 Conference.mpg 1 hour, 50 minutes https://www.youtube.com/watch?v=uZOZYYPmUnM --- On Sat, 4 Mar 2017 01:37:18 +0800 Elias Mårtenson wrote: In GNU APL, try this instead : "a"[1] The reason this seems inconsistent is because single quote is used to define a string, i.e. an array of characters. Except the case where there is only a single character, in which case it represents a scalar character. GNU APL allows you to use double quote instead which doesn't have this inconsistency. That should make things a bit more clear, I hope. Regards, Elias On 4 Mar 2017 01:29, wrote: i just watched a great video on apl and this was discussed i still don't know what the harm/problem would be if instead of returning 'nothing' ⍴'a' why doesn't it return 1 - there is something there please don't mention scalar i know all about it - but to me this has always been an inconsistency in apl that made no sense to me ⍴'aa' the , isn't required in ⍴,'aa' to be consistent ?? 2 ⍴,'a' 1 'a'[1] RANK ERROR 'a'[1] ^ ^ 'ab'[1] a (,'a')[1] a under what condition would 'a'[1] returning 'a' be a problem? ``` ``` ```