DMD 0.148 release

[Wang Zhen]

Derek Parnell wrote:
> On Sun, 26 Feb 2006 17:29:03 +1100, Wang Zhen <nehzgnaw at gmail.com> wrote:
> 
>> Derek Parnell wrote:
>>
>>> On Sun, 26 Feb 2006 12:54:15 +1100, Walter Bright   
>>> <newshound at digitalmars.com> wrote:
>>>
>>>> Lots of new stuff, I added new threads for them in the digitalmars.D
>>>> newsgroup.
>>>>
>>>  Well you almost got bool right <G> Everything except that it does  
>>> implicit  conversion to int. That is just a cheap cop out for lazy  
>>> coding, IMNSHO.
>>
>>
>> Pardon my ignorance,
> 
> 
> That's okay.
> 
>> but why does D need a primitive type for booleans in the first place?  
>> What's wrong with "alias ubyte bool;" or "alias int bool;"?
> 
> 
> The short answer is that booleans are not numbers. They represent truth  
> and falsehood.
> 
>> Can't we simply treat zero as false and non-zero as true as we C  
>> programmers always do?
> 
> 
> *We* are not C programmers ;-) *We* have grown up from that baby-talk ;-)
> 
> Zero is frequently used to implement the concept of falsehood and 
> likewise  non-zero for truth, however the semantics of integers is not 
> the same as  the semantics of booleans. But because many C programers 
> are just *so*  used to thinking this way they have become to believe 
> that zero *is*  falsehood rather than just a number chosen to implement 
> the concept.

32-bit int is frequently used to implement the concept of integers, but 
they are semantically different. So what? Be a language purist and 
refuse to call int an integer until programmers can store arbitrary 
integers without having to worry about the implementation details?



> It is quite possible for a language to implement falsehood/truth is 
> ways  other than using integers but even if they do, the compiler can 
> still  ensure that the sematics are adhered to rather than continue 
> using integer  sematics.
> 
> The only thing I can see wrong with D's new boolean is that it still  
> pretends its a number. Why is this wrong? Because it can lead to coding  
> mistakes and abuse. Thus making maintenance more costly than it needed 
> to  be.

Pretending that bool is not a number can possibly lead to more confusion 
and misuse. Besides, many other features can also be abused in a 
practical language like D. Abandon them all just in case some 
unconscious programmer might make a mistake?


> Walter is still living in the C/C++ past with this concept, which is  
> strange seeing he has implemented so many progressive concepts in D.  
> Boolean as an integer is just retro.

I'm still not convinced why oldschool integer bools are inferior to 
newschool bools which may be abused by pointer tricks anyway.