Bools reloaded

[Don Clugston]

Tom wrote:
> In article <du9cnl$2h9j$3 at digitaldaemon.com>, Bruno Medeiros says...
>> Don Clugston wrote:
>>> Tom wrote:
>>>> In article <du71jc$1e9h$1 at digitaldaemon.com>, Bruno Medeiros says...
>>>>> Walter Bright wrote:
>>>>>> "Tom" <Tom_member at pathlink.com> wrote in message 
>>>>>> news:du049t$2uv2$1 at digitaldaemon.com...
>>>>>>> Yes, PLEASE, WHY?? Just ONE argument against pure bools, only one 
>>>>>>> and I shut my
>>>>>>> mouth forever!
>>>>>> One should be very careful about stepping away from C's implicit 
>>>>>> promotion rules for a language that aims to be a successor to C. C 
>>>>>> absolutely *buried* Pascal.
>>>>>>
>>>>> Uuh, I'm not sure what Tom meant by "pure bools", nor I'm sure what 
>>>>> you meant by "C's implicit promotion rules" (as C doesn't even have a 
>>>>> bool). But ok, nevermind, let's pause for a moment, and get our facts 
>>>>> straight.
>>>>>
>>>>> What exactly is it in bools that you Walter, want and not want?
>>>>> I already know that the ability to write 'while(1)' as the same as 
>>>>> 'while(true)' is one of them, but, anything more?
>>>>> Is the behaviour of having an "implicit promotion" something you want 
>>>>> too?
>>>>> If so, promotion from where, from int to bool, or from bool to int?
>>>>> Do you want or not want bool numeric operations to be an error (like 
>>>>> boolA / boolB*2) ?
>>>> You should read the latest posts about this stuff (the most with 
>>>> subject "Re:
>>>> DMD 0.148 release"). It's all said there. By "pure bools" I mean the 
>>>> *purist
>>>> kind* of boolean type. A boolean type that abstracts us from the 
>>>> implementation.
>>> Sorry, that's still not clear.
>>> Bruno is right, terms like "pure bools" or "purist bools" are vague, you 
>>> can't expect everyone to know what you mean.
> 
> [snip]
> 
>> Derek made a post some time ago with one such definition 
>> (news://news.digitalmars.com:119/14shfnb64x5o2.17cec6fac7wnu.dlg@40tude.net).
> 
> And that is exactly what I meant when I said that you should read the latest
> posts on the stuff :)

And if you read that post, you will find that Derek said:

** It can be explicitly cast to an integer such that false is 0, and 
true is 1.

whereas Kyle said:

integer operations are illegal, and it cant be cast to anything.

So there are at least four types of bool being discussed. Probably more.
And at least two can be called "pure bool".
(a) the existing bool
(b) Bruno and I are in here somewhere, and are not necessarily the same.
(c) Derek
(d) Kyle

Right now, (a) and (c) are the only ones which are clearly defined.