D1 -> D2

[Denis Koroskin]

On Sat, 20 Nov 2010 04:14:05 +0300, Walter Bright  
<newshound2 at digitalmars.com> wrote:

> Andrew Wiley wrote:
>> I'm a fan of parsing false version blocks, but it seems like there  
>> should be some sort of exception for version blocks for a different  
>> version of the language. Could they just be skipped with a warning that  
>> an unknown version of the language is in use? It's somewhat hackish,  
>> but to me, that seems better than parsing it and giving an error  
>> because of syntax changes.
>
>
> How can it skip it without knowing the grammar?

#ifdef D_Version2
...
#else
...
#endif


D has a precedence of having preprocessor macros (e.g #line) even if it's  
not a full-fledged preprocessor, and I don't see why it couldn't adapt the  
same solution.

FWIW, C# has #if blocks, too.