Digraphs *and* Unicode pretty-glyphs, for arrows, triangle, etc.

Allen Wirfs-Brock allen at wirfs-brock.com
Tue Apr 10 09:19:08 PDT 2012

On Apr 10, 2012, at 3:16 AM, Erik Corry wrote:

> 2012/4/10 Andreas Rossberg <rossberg at google.com>:
>> ...
>> No need to burden the language with multiple representations. Algol 68 tried
>> and failed :).
> I think Unicode support has come a long way since then.

PL/I tried it and succeeded. It its early days (only a couple years before Algol 68) it had to exist in a world where 026 card punches still existed.  026's didn't support many useful characters such as >, < , [, ], etc. So PL/I had digraphs for use on legacy input devices and pretty-glyphs for use with "modern" input devices.  Over-time the digraphs faded from use.

Something similar happened with FORTRAN.  Prior to FORTRAN 90 you had to say .LT. instead of < but now it supports a full suite of Ascii operators in addition to the original 026-based character sequences. 


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