An "is_string" BIF?

[Corrado Santoro]

Dear all,

I need an "is_string" function, something that behaves as follows:

is_string ("ABC") -> true
is_string ([65,66,67]) -> true
is_string (['1','2',three]) -> false
...

I know that I could do that by defining a suitable function, but I would 
like to use it in a guard. Is there a sort of BIF?

Cheers,
--Corrado

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Eng. Corrado Santoro, Ph.D.

University of Catania - Engineering Faculty
Department of Computer Science and
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