Re: [boost] Re: Spirit syntax -- another suggestion.

From: Douglas Gregor (gregod_at_[hidden])
Date: 2001-05-31 11:15:23

On Thursday 31 May 2001 11:30 am, you wrote:
[snip]
> It's a bit like writing fractions with the denominator on top. Nothing
> really wrong with the idea, but it goes strongly against convention,
> and I guarantee it would confuse intelligent people. Or try learning
> German numbers, where you have to say drei und zwanzig instead of 23.
> Why do otherwise intelligent learners of German sometimes get their
> numbers backwards?

The fractions analogy doesn't quite fit, because the accepted version 
(denominator on the bottom) and the mutated version (denominator on top) have 
the same syntax but different meanings and it is impossible to tell from the 
syntax which meaning is intended. With prefix vs. postfix * and +, there is 
no ambiguity because:
        1) the syntax is different for each
        2) Spirit doesn't use postfix + or *
        3) Regular expressions don't use prefix + or *

> Anyway, if you already have the syntax a(0,more), then you could save
> '*' for some other use. After all, there are lots of finite state
> operations a person might want to define (again I refer for example to
> XFST: www.xrce.xerox.com/research/mltt/fst/fssyntax.html), and C++
> offers only a limited range of operators for you to play with.
>
> -- Dale Gerdemann

        Doug