Hello all, while experimenting with GNU APL vs. Dyalog APL today I found something...
Dyalog's site had this Christmas 'doodle' on their site recently, which draws an ASCII Christmas tree:
' /\'[1+(⌽,+⍨)∘.≥⍨⍳10]⍪9 2 9/↑'∘⌹∘' ' ⌹ '
/\
//\\
///\\\
////\\\\
/////\\\\\
//////\\\\\\
///////\\\\\\\
////////\\\\\\\\
/////////\\\\\\\\\
//////////\\\\\\\\\\
∘∘∘∘∘∘∘∘∘⌹⌹∘∘∘∘∘∘∘∘∘
⌹⌹
Apart from the fact that the _expression_ as a whole doesn't execute in GNU APL, the sub _expression_ at the end which prints out the 'bottom' and 'trunk' of the tree acts differently in Dyalog vs. GNU APL.
[Dyalog]
9 2 9/↑'∘⌹∘' ' ⌹ '
∘∘∘∘∘∘∘∘∘⌹⌹∘∘∘∘∘∘∘∘∘
⌹⌹
[GNU]
9 2 9/↑'∘⌹∘' ' ⌹ '
∘∘∘∘∘∘∘∘∘⌹⌹∘∘∘∘∘∘∘∘∘
Is it unexpected that GNU APL does not apply the Compress (/) across multiple right-hand items? (Please forgive my likely incorrect terminology -- still learning).
Being so new to APL, I don't mean to imply in any manner that I think GNU APL has a bug -- as I understand it, GNU APL follows 'APL2' more whereas Dyalog has implemented various extensions -- but would like to understand just what's going on here.
BUILDTAG:
---------
Project: GNU APL
Version / SVN: 1.8 / 1369
Build Date: 2020-12-04 18:52:09 UTC
Build OS: Linux 5.6.7_p1-debian-sources x86_64
config.status: default ./configure options
Archive SVN: 1359
Thank you,
-Russ