Re: question about linker

James Kuyper <jameskuyper@alumni.caltech.edu> wrote:

On 12/12/24 06:38, Janis Papanagnou wrote:

On 12.12.2024 06:35, Keith Thompson wrote:

Janis Papanagnou <janis_papanagnou+ng@hotmail.com> writes:
[...]

For (yet another) example; my K&R shows a syntax for expressions like
>
expression := binary
binary := binary + binary
binary := binary * binary

>
That's odd. Is that an exact quotation?

>
No, not exact, I abbreviated it; omitted about 25 other operators and
used another syntax (no ' | '). (Trust me that it hasn't things that
I called 'factor' and 'term' in my post, which is equivalent to what
you have formulated below in your copy.) - I'm using a translation of
something that someone classified as being a "pre-second" edition but
not quite the first edition. Two references point to 1977 (Prentice
Hall) and 1978 (Bell Labs). - The text for the "binary" syntax has two
optional informal columns, the first one has the comment "precedence"
for some of the variants of "binary" operators. (But it's also just
titled as "Syntax in Short"; probably presented in a form to make it
easy to understand without overloading it for purpose of a textbook.)
It serves the purpose to explain an ambiguous syntax with non-codified
precedence and a separate precedence table (but it's not an exact "C"
syntax description as you'd probably find it in standards documents).

 
My copy of K&R 1st edition has nothing remotely resembling that. I
cannot find "binary" as an element of the grammar anywhere. There are 16
grammar rules for "expression". The one that comes closest is
"expression binop expression", where binop is one of C's 19 binary
operators, divided into 12 different priority levels.

Apparently translators took freedom to make various changes.
Polish translation of 1st edition has rules with translated
names for nontermials.  There are 17 rules for expressions,
one of which contains binary operator.  Text following this
listens 18 binary operators, divided into 10 priority levels.
Translators claimed that they removed inaccuracies, but
probably planted extra confusion by having extra rule for
comma operator and relating priority of assignment operators
and other operators.

BTW: Polish translators also changed examples for K&R style
to Allman style...

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