Article: Increasing the D Compiler Speed by Over 75%

[John Colvin]

On Monday, 29 July 2013 at 12:35:59 UTC, John Colvin wrote:
> On Monday, 29 July 2013 at 12:17:22 UTC, JS wrote:
>> Even something like
>>
>> for(;;)
>> {
>>   if (random() == 3) break;
>> }
>>
>> is decidable(it will halt after some time).
>
> That program has a finite average runtime, but its maximum 
> runtime is unbounded. You can't actually say it *will* halt. 
> For any given input (in this case 0 inputs) one cannot tell 
> whether the program will eventually halt, therefore it is 
> undecidable.
>
> I have formal background in CS so I might have got that totally 
> wrong.

sorry, that should be "I have NO formal background in CS"