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

From: joel de guzman (isis-tech_at_[hidden])
Date: 2001-06-01 11:13:49

From: "Greg Colvin" :

> > > And don't forget
> > > 
> > >    a*b*c
> > > 
> > > Commutative for numbers, but not matrices, and a common
> > > substitute in computer languages for
> > > 
> > >    a b c 
> > > 
> > > in algebra.  Nice high precedence too.
> > 
> > Clashes with the Kleene star.
> 
> What clash?  If
>    A * A
> in Spirit means
>    A A
> in EBNF and if
>    *A
> in Spirit means
>    A*
> in EBNF then
>    *A
> in Spirit matches nothing, or
>    A
> or
>    A * A
> or
>    A * A * A
> and so on.
> 

Hello Greg,

That's the coolest argument I've seen so far!
At first I didn't get it but a second look and 
omi-gosh, he's right!!! You are great, man!

a b <in math> ----> a * b <in programming>
a b <in BNF> ----> a * b <in Spirit>

nice parallels!

*a ---> nothing | a | a * a | a * a * a | a * a * a * a....

<star> a means repeat the <stars> as many as you want.
And as many stars as the heavens!

I'm convinced. I vote for the star :-)

-Joel de Guzman

PS> Some trivial bug fixes by Colin McPhail. Please
download the latest version. I will upload into boost's 
vault as soon as the ports and tests done by those
concerned have become stable.