Semicolon can be left out after do-while

[Steven Schveighoffer]

On Tue, 12 Apr 2011 18:00:40 -0400, spir <denis.spir at gmail.com> wrote:

> On 04/12/2011 11:51 PM, Steven Schveighoffer wrote:
>> On Tue, 12 Apr 2011 17:21:57 -0400, spir <denis.spir at gmail.com> wrote:
>>
>>> On 04/12/2011 09:21 PM, Steven Schveighoffer wrote:
>>>
>>>> int main(){
>>>> int a,b;
>>>> do{
>>>> scanf("%d %d",&a,&b);
>>>> }while(a<b) //note missing semicolon here
>>>> return 0;
>>>> }
>>>>
>>>> The grammar specifies this correctly, but then again, the example  
>>>> uses the
>>>> semicolon.  
>>>> (http://www.digitalmars.com/d/2.0/statement.html#DoStatement)
>>>> [...]
>>>> I think the grammar should be changed...
>>>
>>> yop!
>>>
>>>> This is almost as bad as go's
>>>> requirement for if statement opening block to be on the same line...
>>>
>>> why? I like Go's syntactuc diffs. (except for its "multi-for")
>>
>> in Go, this:
>>
>> if(x)
>> {
>> gosWriteRoutineThatIDontKnowTheSyntaxOf("hello")
>> }
>>
>> is equivalent to this in D:
>>
>> if(x)
>> {
>> }
>>
>> writeln("hello");
>>
>> This is frankly unforgivable IMO.
>>
>> Of course it's fixable, but the attitude that "the coder should know  
>> better"
>> doesn't really make me comfortable with it. And I hate the "brace on  
>> the same
>> line" format (but this of course is not a real argument against it).
>
> Oh, that's what you meant! I find this a Good Thing, in that it enforces  
> one bracing style (the right one, that does not eats one more line for  
> just a '{').

No, it doesn't enforce anything.  The above compiles and runs.  What it  
does is introduce subtle bugs.

The way to fix it is to make the above an error.

> About knowing or not about this (non/mis/-)feature, it's written down,  
> and clearly, in all Go docs I've read. And one cannot miss it for very  
> long anyway ;-)

I know that if(xyz); is not *ever* what I meant, but in C it compiles.   
However, in D, it tells me I shouldn't do that.  What results is less bugs  
because I can't make that mistake without the compiler complaining.

I'm not saying that the spec isn't well defined, or the manual isn't  
clear, what I'm saying is, the attitude reflected in the rule is that  
greater burden is put on the developer to make sure they follow the rules  
without compiler enforcement.  It makes me want to not use Go.  And in  
fact, I will probably never use it as long as this rule is in place.

> Maybe, if not done already, a line starting with an opening brace should  
> generate a parsing error.

Typically this is used to create a new scope in C/D/Java/C#.  This allows  
declaring temporary variables, not sure how it is in Go, but I'd assume  
something similar.

-Steve