Overloading and Literal Numerics

[Jon Fairbairn]

> Jon Fairbairn <Jon.Fairbairn@cl.cam.ac.uk> writes:
> =

> > data Port =3D Tcpmux | Nbp | Echo_ddp | Rje | Zip | Echo_tcp | ...
> >              deriving Enum, ...
> > instance Num Port where ...
> =

> Or, alternatively, just use Strings, and have a portFromString first
> check /etc/services for a match, then try to parse the string as a
> positive integer, and finally generate an error if no valid port can
> be determined?

Possibly, if there's really no way of making sure the error
happens at compile time.

-- =

J=F3n Fairbairn                                 Jon.Fairbairn@cl.cam.ac.u=
k
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