make Char not an Integer?

[malmaud]

Right now, bool("0") causes ERROR: no method bool(ASCIIString). It might make sense to define it as bool(x::String) = bool(int(x)).

Also, bool('0') somewhat surprisingly returns true, because it's dispatching to bool(::Number). It probably makes more sense to either have that return false or raise an error.

[JeffBezanson]

We like to avoid equating strings and numbers.

We could make conversion to Bool stricter and only accept arguments equal to 0 or 1. It also seems like x!=0 is clearer than bool(x) in many cases.

Generally it would be nice to make Char less of a numeric type. Adding an Ordinal abstract type has been raised in the past.

[quinnj]

I think we should just define:

bool(x::Char) = throw(ArgumentError("can't convert Char to Bool"))

[StefanKarpinski]

I think we should just delete the bool function entirely.

[JeffBezanson]

However there is still convert(Bool, '0').

[quinnj]

Yeah, probably better to get rid of bool and convert(Bool,x).

[JeffBezanson]

Well, the bool(), int() etc. functions are sketchy, but it seems weird to disallow conversion to Bool.

[quinnj]

Actually, this is probably another case where the coerce() could come in handy. convert could throw or be no method while current behavior would be in coerce().

[JeffBezanson]

If we change our integer conversions to check for overflow, then converting to Bool would only allow arguments equal to 0 or 1.

[simonster]

Is it intended that Bool conversions are still unchecked?

[JeffBezanson]

For now yes, but I'm not totally sure what to do about it. Being non-zero is well established to correspond to trueness. However I'm not sure what the use cases are for conversion to Bool. It seems you'd always be better off writing x != 0 if that's what you want.

[jakebolewski]

Closed by #8816.