Re: Top 10 most common hard skills listed on resumes...

Kaz Kylheku <643-408-1753@kylheku.com> writes:

On 2024-08-31, Bart <bc@freeuk.com> wrote:

[...]

I can also say that the C grammar is buggy:
>
  assignment-expression:
     conditional-expression
     unary-expression asssignment-operator assignment-expression

>
I second that.  If I had energy and motivation for that sort of
thing, I would submit a defect report.
>
There is no value (no pun intended) in constraining the left side
of an assignment to just that class of expression that might
produce a modifiable lvalue, since that constraint must be checked
regardless.
>
It creates an gratuitous inconsistency between the formal ISO C
grammar and the intuitive precedence model for expressions that
everyone understands.  Even the K&R2 book has a precedence table
(P. p53?).
>

When attempting to parse an assignment-expression, do you go for
a conditional-expression or unary-expression?

>
If using a parser generator tool, like one of the Yacc
derivatives, I would just make it:
>
  expr : ... /* numerous rules */
       | expr '=' expr { ... }
       | ... /* numerous rules */
       ;
>
using %left and %right declarations to set up the operator
precedences and associativities.
>
Anything you do differently from a specification, though, creates
risk.  It takes extra work to show that what you have is
equivalent.

This idea is totally wrongheaded.  The most important purpose of
the ISO C standard is to be read and understood by ordinary C
developers, not just compiler writers.  The grammar in the C
standard is both easy to understand and a precise and accurate
specification for what syntax is accepted.  Furthermore it is
written in a way that doesn't encourage any particular parsing
technology, which is definitely a benefit, because it promotes
looking at alternate approaches.  On the last point, it is much
more important that developers be able to tell when a compiler
is doing things wrong than it is for compiler writers to be
sure they have met a specification, because if it is the
slightest bit difficult for developers then they will start to
rely on compilers as the ultimate authority rather than the C
standard itself, which is a very bad thing.