Re: Why are ambiguous grammars usually a bad idea? Why are languages usually defined and implemented with ambiguous grammars?

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From	gah4 <gah4@u.washington.edu>
Newsgroups	comp.compilers
Subject	Re: Why are ambiguous grammars usually a bad idea? Why are languages usually defined and implemented with ambiguous grammars?
Date	Thu, 30 Dec 2021 13:40:32 -0800 (PST)
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On Wednesday, December 29, 2021 at 7:28:33 PM UTC-8, gah4 wrote:

(snip, I wrote)

> This reminds me of learning associativity of exponentiation (**)
> in Fortran IV (I believe it isn't in the Fortran 66 standard) before I
> learned it in algebra class. I suspect that there are others I learned
> from programming before learning them in math class

(snip)

> [Fortran has always had ** exponentiation, starting with the original
> version in 1956. It always bound tighter than +-*/ but wasn't
> associative, A**B**C not allowed, -John]

It was, at least, in Fortran IV for IBM 360/370:

https://atariwiki.org/wiki/attach/Fortran/IBM_FORTRAN_IV-Language_1973.pdf

My 8th grade graduation present was the above manual, though maybe
one year earlier.   I used to read IBM reference manuals like books,
from start to finish.  By the end of summer, I had run many Fortran programs.

As well as I know it, IBM Fortran IV was the input to the 1966 standard,
but not all features were included.  It might also be that extensions were
added later.
[I used Fortran H on Princeston's 360/91 in a summer job I had in
college in about 1973. -John]

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