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Re: for or against equality, was Why are ambiguous grammars usually a bad idea?

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On Monday, January 3, 2022 at 11:58:39 AM UTC-8, mac wrote:
> > [Interesting take. In reality, of couse, BASIC borrowed that from Fortran. Algol
> > used := for assignment, different from = for equality comparison. -John]

> Indeed.
> Unfortunately, assignment is probably the single most common operator.
> The ASCII committee should have kept the left-arrow character instead of
> replacing it with underscore.

The assignment statement in BASIC, at least the ones I know, has an
(optional) LET keyword, so it might say:

10  LET A=3

Most people leave it off, though.

Is PL/I the only language that uses = for both assignment and the relational operator?
Since expressions are not statements, it avoids the ambiguity that would otherwise occur.
I believe some BASIC also use = for both.

Underscore is a pretty useful character.

The two ASCII characters that don't exist in EBCDIC are ^ and ~.
Two EBCDIC characters that don't exist in ASCII are 𝇍 (cent)
and ¬ (logical NOT sign).  Conversion tables usually cross
map those pairs.  (PL/I, at least, uses ¬ and ¬= operators.)

[In original Dartmouth BASIC the LET was mandatory, but it was a considerably
smaller and fully compiled language than the later dialects.  On the other
hand, PL/I made a fetish of nothing being a reserved word, e.g.

  IF IF = THEN THEN ELSE = BEGIN; ELSE END = IF;

-John]

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Re: Why are ambiguous grammars usually a bad idea? Why are languages usually defined and implemented with ambiguous grammars? Kaz Kylheku <480-992-1380@kylheku.com> - 2021-12-29 18:48 +0000
  Re: Why are ambiguous grammars usually a bad idea? Why are languages usually defined and implemented with ambiguous grammars? Jan Ziak <0xe2.0x9a.0x9b@gmail.com> - 2021-12-29 16:05 -0800
    Re: Why are ambiguous grammars usually a bad idea? Why are languages usually defined and implemented with ambiguous grammars? Kaz Kylheku <480-992-1380@kylheku.com> - 2021-12-30 18:00 +0000
      Re: Why are ambiguous grammars usually a bad idea? Why are languages usually defined and implemented with ambiguous grammars? Kaz Kylheku <480-992-1380@kylheku.com> - 2021-12-30 20:08 +0000
  Re: Why are ambiguous grammars usually a bad idea? Why are languages usually defined and implemented with ambiguous grammars? gah4 <gah4@u.washington.edu> - 2021-12-29 18:41 -0800
    Re: Why are ambiguous grammars usually a bad idea? Why are languages usually defined and implemented with ambiguous grammars? Kaz Kylheku <480-992-1380@kylheku.com> - 2021-12-30 18:14 +0000
      Re: Why are ambiguous grammars usually a bad idea? Why are languages usually defined and implemented with ambiguous grammars? Jan Ziak <0xe2.0x9a.0x9b@gmail.com> - 2021-12-30 13:47 -0800
        Re: What does = mean, was Why are ambiguous grammars usually a bad idea? Jan Ziak <0xe2.0x9a.0x9b@gmail.com> - 2021-12-30 17:10 -0800
        Re: Why are ambiguous grammars usually a bad idea? Why are languages usually defined and implemented with ambiguous grammars? mac <acolvin@efunct.com> - 2022-01-03 19:51 +0000
          Re: for or against equality, was Why are ambiguous grammars usually a bad idea? gah4 <gah4@u.washington.edu> - 2022-01-03 21:07 -0800
            Re: for or against equality, was Why are ambiguous grammars usually a bad idea? Thomas Koenig <tkoenig@netcologne.de> - 2022-01-04 19:23 +0000
            Re: for or against equality, was Why are ambiguous grammars usually a bad idea? gah4 <gah4@u.washington.edu> - 2022-01-04 13:26 -0800
    Re: Why are ambiguous grammars usually a bad idea? Why are languages usually defined and implemented with ambiguous grammars? gah4 <gah4@u.washington.edu> - 2021-12-30 13:40 -0800
  Re: why do people choose a language, was Why are ambiguous grammars usually a bad idea? Jan Ziak <0xe2.0x9a.0x9b@gmail.com> - 2021-12-30 20:19 -0800

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