Migrating dmd to D?

[Zach the Mystic]

On Saturday, 2 March 2013 at 10:05:08 UTC, Daniel Murphy wrote:
>
> "Zach the Mystic" <reachBUTMINUSTHISzach at gOOGLYmail.com> wrote 
> in message
> news:bueceuemxqmflixkqbuz at forum.dlang.org...
>> On Saturday, 2 March 2013 at 04:28:40 UTC, Zach the Mystic 
>> wrote:
>> You would definitely need an identifier translation table:
>>
>> "Dsymbols *" -> "Dsymbol[]"
>
> Might as well just define ArrayBase etc
>
>> "NULL" -> "null"
>
> Sure, but what about all the places 0 is used to mean NULL?
>
>> `//printf("...%d...", s)` -> `writef("...%s...", s)`
>
> Why not just keep it as printf?
>
>> "#ifdef XIFDEFVERSION" + nested ifdefs + "#endif"
>> -> "version(XIFDEFVERSION) {" + nested {}'s + "}"
>>
>> "#ifdef 0" -> "version(none)"
>>
>
> No luck, dmd source uses #ifdefs mid-declaration, 
> mid-statement, and
> mid-expression (even mid-string-literal)
> It also uses #ifs with complex conditions.
>
> And don't forget no-args ctors, implicit calling of ctors, 
> stack allocated
> classes, new keywords, narrowing integer conversions, 
> 'virtual', pure
> virtual function syntax, macros as expression aliases, string 
> literal
> constness, the EXP_CANT_INTERPRET cast hack, macros, 
> namespaces, macros,
> structs using inheritance, and of course more macros.

Every single one of these would have to be special-cased. If you 
had a domain-specific language you could keep track of whether 
you were mid-declaration, mid-statement, or mid-string-literal. 
Half the stuff you special-case could probably be applied to 
other C++ projects as well.

If this works, the benefits are just enormous. In fact, I would 
actually like to "waste" my time trying to make this work, but 
I'm going to need to ask a lot of questions because my current 
programming skills are nowhere near the average level of posters 
at this forum.

I would like a c++ lexer (with whitespace) to start with. Then a 
discussion of parsers and emitters. Then a ton of questions just 
on learning github and other basics.

I would also like the sanction of some of the more experienced 
people here, saying it's at least worth a go, even if other 
strategies are simultaneously pursued.