const by default.

[Boris Wang]

"kris" <foo at bar.com> ??????:e8cu1q$nbc$1 at digitaldaemon.com...
> Chad J wrote:
>> So far I'm pretty convinced that some kind of "constness" is a good 
>> thing.  I've already run into one area where this would be useful.
>>
>> I have one peeve about it though: I really would not like it if the 
>> keyword used to represent constness was "const".  I will explain from my 
>> newbie-to-Cplusplus background, having come from languages that seem, at 
>> least to me, to be much more well thought out than Cplusplus.
>>
>> When I see "const" I think of it as a shorthand for "constant", just as 
>> "bool" is shorthand for "boolean".  My understanding of something 
>> constant is that it does not change... EVER.  Thus it makes no sense to 
>> me why something as ephemeral as data passed into a function could be 
>> considered constant.  If the constant data leaves the scope of the 
>> function, becomes no longer constant, and gets changed, then it isn't 
>> really constant to me.
>>
>> I do like the mutable word though, as it seems to have an english meaning 
>> very close to its programming meaning  :)
>> It also seems that if we were to make things immutable by default, we 
>> could make an "immutable" keyword.  Sure it's kinda long, but since most 
>> things are that by default then we won't be typing it much.  It also 
>> seems so much more logically related to the word "mutable".
>>
>> Another worry I have is that of being stuck with many instances of 
>> "mutable" littering my code, if only because said code happens to modify 
>> referenced data a lot.  One way I might see this worry dissappearing if 
>> there was a way to blanket stuff into being immutable, in order to avoid 
>> repeating the word over and over again.  Sorta like:
>>
>> class Foo
>> {
>>   mutable:
>>     int[] data; // this is mutable
>>     char[] name; // this too
>>     // etc
>> }
>>
>> or maybe even something as radical as
>>
>> mutable
>> {
>>   // from now on everything works as it used to
>>
>>   void func1( char[] string1, char[] string2 )
>>   {
>>     string1[5] = 'a'; // ok
>>     string2[3] = 'b'; // also good
>>   }
>>
>>   void func2( int[] data )
>>   {
>>     data[8] = 42; // just dandy.
>>   }
>> }
>>
>> Note:  I am probably so newbish at language design compared to you guys 
>> it is not even funny, so maybe the syntax suggestions suck, but please 
>> consider my naming plea, at least as a "this experience was unpleasant so 
>> please fix it" sorta thing.
>
>
> hehe -- that would certainly resolve the problem for existing libraries: 
> just wrap each entire module in a mutable{} block -- phobos would be done 
> in 15 minutes :D
>
> Good idea!
>

NO, Yet another colon / brace syntax.