Plankalkül had the advantage of not having to run on a real machine.
As far as := is concerned having to use the shift key for an assignment is less than ideal but there really aren't any better options on a modern keyboard. I think C's use of = is a bit braindamaged but it is nice and quick to type.
On an ASR33 = is the character you have press shift for. : is unshifted.
Many early video terminals and microcomputers had similar layouts, because they were easy to implement. https://en.wikipedia.org/wiki/Bit-paired_keyboard
Re:Why Does “=” Mean Assignment?
by roywiggins on Tuesday April 10, 2018 @06:46PM
(#16806306)
It didn't actually contribute much to the evolution of other languages though, right? Had anyone even heard of it when Fortran/ALGOL/etc were being designed?
Zuse seems to have been under the impression that some of the ALGOL designers were aware of it: https://books.google.com/books?id=AsvSBQAAQBAJ&pg=PA522&lpg=...
Rutishauser was, at least.
Plankalkül for example was out a decade earlier and used →. EX:
https://en.wikipedia.org/wiki/Plankalk%C3%BClSo, there really was a lot of languages out there, but := was fairly common because it was easy to parse and type.