Re: string_lower producing atoms

On Tue, Mar 11, 2014 at 6:02 AM, Peter Berry <[email protected]> wrote:

> ?- string_lower("Foo", X), X = "foo".
> false.
>
> ?- string_lower("Foo", X).
> X = foo.
>
> ?- string_lower("Foo", "foo").
> true.
>
>
> Is there any particular reason for this? Isn't the point of strings to
> avoid the overhead associated with atoms?
>

It looks like string_lower/2 is using a slightly more general definition of
"string" which includes both string objects and atoms.  For example, you
can also provide an atom as the first argument.

Since we already have downcase_atom/2, I can't think of any reason why we'd
want string_lower/2 to behave this way.

-- 
Michael
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