Re: [boost] Re: Automata builder -- interface

From: George A. Heintzelman (georgeh_at_[hidden])
Date: 2001-05-30 13:17:48

> Example:
> 
> a = b;
> a = c;
> a = d;
> 
> Equivalent to:
> 
> a = b | c | d;
> 
> But there's a runtime penalty.

I appreciate that you don't allow this syntax, but if you were to 
change your mind, I would find the equivalence you state above very 
counter-intuitive. I would expect the three assignments to be 
equivalent (if there were no intervening statements) to just a = d.

I would expect that:

a = b; a |= c; a |= d;

to be equivalent to 

a = b | c | d;

If you ever allow rules to be redefined, please be careful about the interface you decide to use for it. Very important would be the case:

Rule a = <pattern 1>
Rule b = <pattern 2>
Rule c = a | b;

b = <pattern 3>

Now, does using c give you <pattern 1> | < pattern2> or <pattern1> | <pattern3> ? I think I would want it to be the former, but I can see arguments both ways.

But since this isn't done right now, I guess it is mostly a moot point...

George Heintzelman
georgeh_at_[hidden]