D grammar overhaul

[Rainer Schuetze]

Before going into details with the grammar, I'd like to clarify one 
thing regarding the lexer, that also has some influence on the grammar:
Do we want to allow spaces and comments between these tokens?

- ! in
- ! is
- extern ( C ++ )
- @ Property (safe, trusted, disable, etc)

here is some example code which also shows an ambiguity introduced by 
combining these from seperate tokens:

extern(C
//
++) void foo();

@ /* comment inside
property */ safe int bar() { return 0; }

void main()
{
	int[int] a;
	struct S { int x; }
	S s;
	int b;

	if (1 ! /* still an infix operator? */ in a) {}
	if (null ! /* still an infix operator? */ is null) {}
	
//	if (s.x !in a) {} /* does not compile: 
http://d.puremagic.com/issues/show_bug.cgi?id=5785 */
	if (b !in a) {} // but this compiles!?
}



Trass3r wrote:
> Original discussion forked in the D grammar thread, so I'm opening a new one for this specific issue.
> The D grammar is in dire need of an overhaul.
> 
> I suggest we discuss changes here and then put everything into github to issue a pull request once everything's done.
> I already forked the d-programming-language.org repo to get started by fixing some mistakes. Hereafter I list some issues that come to my mind.
>