(j3.2006) Suppress macro token replacement

[Aleksandar Donev]

Hello,

In thinking about keywords for macro actual arguments, I realized that we 
still need a mechanism to suppress token replacement in certain cases, so 
that a lexical token that happens to be X may remain as just an X and not be 
replaced when X is the name of a macro dummy argument. For example, in

MACRO M(X)
 EXPAND Y(X=X)
END MACRO

it would be nice if it is possible to use X as a keyword. Maybe this is too 
much to ask, but it seems to me that programmers are used to Fortran syntax 
where the lexical token X can be used for several different purposes 
(variable name, keyword, label, etc.) without ambiguity. Maybe a way to 
unquote a string would do it. Using fake $ syntax to denote a "macro 
function":

EXPAND Y( $UNSTRING("X") = X )

Yet one more rather useful macro feature present in other macro languages is 
the ability to "quote" (convert to string) after expansion:

WRITE(*,*) "Compiled for type=", $STRING(TYPE)

where TYPE may be replaced with "INTEGER(wp)", for example.

I am not sure what good syntax for these would be, but they seem rather useful 
yet absent...

Aleks