[Haskell-cafe] Re: ANN: weighted-regexp-0.1.0.0

[Martijn van Steenbergen]

On 7/27/10 9:58, Sebastian Fischer wrote:
>
> On Jul 27, 2010, at 9:15 AM, Sjoerd Visscher wrote:
>
>> Oh, by the way, with noMatch, eps, alt and seq_ RegExp is itself a
>> Semiring,
>
> Yes, but it's hard to define an Eq instance for arbitrary regular
> expressions that reflects equivalence of regexps.

How hard is this exactly?

Martijn.