a type called 'p' causes conflicts with the generated C code;

single char ids like f, p should be avoided;
renamed types as first, second, third etc

test/cdata.in

 TYPE {
 
-n = a | b | c | d | e;
-o = a( int aa );
-p = a | b;
-q = a | b | c(int cc) | d | e;
-r = a | b | c(int cc) | d( string dd) | e;
-s = a(int aa) | b | c | d | e;
+first	= a | b | c | d | e;
+second	= a( int aa );
+third	= a | b;
+fourth	= a | b | c(int cc) | d | e;
+fifth	= a | b | c(int cc) | d( string dd) | e;
+sixth	= a(int aa) | b | c | d | e;
 
 intlist = null "null" | cons( int first, intlist next ) 1 " , " 2;
 illist  = null "null" | cons( intlist first, illist next ) "[ " 1 " ] , " 2;