Ddoc macro syntax

[Walter Bright via Digitalmars-d]

On 9/15/2016 4:06 AM, Andrei Alexandrescu wrote:
 > I was thinking more about it and figured we could introduce a special macro at
 > the very beginning of a .ddoc file or "Macros:" section called
 > DDOC_MACRO_CALL_SYNTAX. It may be defined one of the following:
 >
 > DDOC_MACRO_CALL_SYNTAX = DDOC
 >
 > That's today's syntax.
 >
 > DDOC_MACRO_CALL_SYNTAX = CPP
 >
 > A macro will be invoked as MACRO(a1, a2).

That will break every usage of function calling examples. (It works in CPP 
because if MACRO is not a macro, the text is left unchanged. In Ddoc, a 
non-existent macro is replaced by the empty string.)


 > DDOC_MACRO_CALL_SYNTAX = $CPP
 >
 > A macro will be invoked as $MACRO(a1, a2)
 >
 > DDOC_MACRO_CALL_SYNTAX = LaTeX
 >
 > Macro invocation is \MACRO{a1}{a2}.
 >
 > This definition is modular, i.e. it doesn't carry beyond the current document
 > (otherwise the semantics of a .dd file depends on the .ddoc file(s) it's used
 > with).
 >
 > Macro definitions stay the same using $1, $2 etc. but macros invoked by them
 > would need to obey the DDOC_MACRO_CALL_SYNTAX defined at the top.


Alternatives:
1. accept more than one syntax
2. have the first encountered usage set the mode