Re: [boost] Re: [ANN] Spirit C++ parser framework.

From: Larry Evans (jcampbell3_at_[hidden])
Date: 2001-06-01 20:11:35

joel de guzman wrote:

> > >
> > > What value is there in paralleling the math domain, since it is
> > > unrelated to the grammar domain?  On the other hand, the string domain
> > > and grammar domain are somewhat closely related.  Since a + b means
> > > concatenation for strings, a + b seems logical for concatenation in a
> > > grammar.
>
> There's no logical value true. But how could we justify
> a certain syntax? One way is to look back and see how
> things were done and parallel these if possible.
>
> I see now that we cannot possibly view the syntax issue
> in a logical perspective. This issue is very subjective.
> It's not about right or wrong. It's about like or dislike.

I agree.  Maybe we're getting too focused on the "look and feel".

>
> I remember how some mathematicians objected to
> = for assignment. i = i+1; is not logically correct.
> The Pascal family used the :=, but the C family
> continued with the =.
>
> I tried for example to find logic behind my dislike for +
> for concatenation. Addition is *not* concatenation, I
> asserted. Addition implies a + b = b + a. Commutative.
> I opted for a non-commutative operator. That was one
> of the reason for Spirit's use of >>, after all I believe
> arrows clearly denote sequencing.

That's one reason I liked >>.  The only reason I suggested &
was that it sorta belonged with |; consequently, would seem more
natural.