What are AST Macros?

[Nick Sabalausky]

"Rainer Deyke" <rainerd at eldwood.com> wrote in message 
news:i1gs16$1oj3$1 at digitalmars.com...
> On 7/12/2010 19:41, Nick Sabalausky wrote:
>> I already agreed to that part ("For writing, yes..."). But there are 
>> other
>> uses that *do* parse, and others that do both. The point is NOT that 
>> string
>> mixins are *always* unsatisfactory as a replacement for AST macros. The
>> point is that *there are perfectly legitimate use-cases* where string 
>> mixins
>> are unsatisfactory as a replacement for AST macros. I think you've 
>> already
>> agreed to this in other posts.
>
> The great strength of string mixins is that you can use them to add the
> AST macros to D.  The great weakness of string mixins is that doing so
> requires a full (and extendable) CTFE D parser, and that no such parser
> is provided by Phobos.
>

Seems to me that would lead to unnecessary decreases in compilation 
performance. Such as superfluous re-parsing. And depending how exactly DMD 
does CTFE, a CTFE D parser could be slower than just simply having DMD do 
the parsing directly.