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

From: joel de guzman (isis-tech_at_[hidden])
Date: 2001-06-01 19:54:16

> > 
> > 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 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.

> 
> I'm fine with +, but Joel has been pushing <<, which I hate.
> I'm suggesting * as a compromise.  Or else we wait for Bjarne's
> overloaded white space proposal to be accepted ;->

Now I ask. Why do you dislike the >> ?

a >> b.... b follows an a in sequence

Have a nice day,
Joel de Guzman