HELP NONSYNTAX John Gibson December 82
nonsyntax <syntax word>
NONSYNTAX preceding the name of a syntax word tells the compiler not to treat
it as such, but instead to treat it as a reference to a variable. Thus for
example
nonsyntax [ -> f;
assigns to F the procedure "[" that is called by the compiler to read a list
constructor expression following the opening "[". F can then be called to do
the same, but only in the context of compilation or of code planting, e.g.
define syntax bra;
f();
enddefine;
bra 1 2 3 4] =>
** [1 2 3 4]
The word NONSYNTAX is essential here; an attempt to use a statement like
[ -> f;
would simply cause the compiler to think this was the beginning of a list
with first 3 elements "->", "F" and ";".
Note that not all syntax words contain procedures as their values; only
those which can OPEN a syntactic construct do so (the procedures are called
to read that construct). Thus words like *ELSE, *ENDIF and *ENDPROCEDURE
do not contain procedures.
NONSYNTAX performs the same 'escaping' role as NONOP does for operators
and NONMAC does for macros - see HELP *NONOP and HELP *NONMAC.