[mercury-users] An enumeration as a type: how to do it?

[Fergus Henderson]

Andrew Bromage wrote:
> 
> If you're only planning to convert in one direction, using a function may
> be a little syntactically cleaner:
> 
> :- func name_int_type(integral_type) = string.
> 
> name_int_type(byte) = "byte".
> name_int_type(short) = "short".
> name_int_type(int) = "int".
> name_int_type(long) = "long".
> name_int_type(char) = "char".

A simpler and more maintainable way of writing this is to use the
predicate functor/3 defined in the `std_util' module:

	name_int_type(Atom) = String :-
		functor(Atom, String, _Arity).

-- 
Fergus Henderson              | Designing grand concepts is fun;
fjh at cs.mu.oz.au               | finding nitty little bugs is just work.
http://www.cs.mu.oz.au/~fjh   | -- Brooks, in "The Mythical Man-Month".
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