[m-dev.] regular expressions

[schachte at cs.mu.OZ.AU]

On 18 Dec, Fergus Henderson wrote:
> On 17-Dec-1999, Michael Day <mcda at cat.cs.mu.OZ.AU> wrote:

>> The repeat0/repeat1 predicates
>> look nice.
> 
> Actually you probably couldn't write it exactly like that in Mercury.
> It would need to be
> 
> 	c_identifier --> letter, repeat0((pred(in, out) is semidet -->
> 					  letter ; digit ; ['_'])).

Bummer.

>> I suppose it would be asking too much for them to be defined as
>> postfix * and + operators, respectively :)
> 
> Yes, that conflicts with the use of * and + as infix operators.

But you could make them prefix operators, which wouldn't be too bad. 
Until you had to do the explicit lambda-like thing.


-- 
Peter Schachte                | I have made this a rather long letter
mailto:pets at cs.mu.OZ.AU       | because I haven't had time to make it
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