commit 2d67137

If a macro name starts with a special character, then that character no longer has a special meaning.

 1@@ -123,9 +123,13 @@ The following nonstandard tokens are available:
 2 
 3  ]\ acts like \: for the matching [@ command.
 4 
 5-For the . ,  : ; commands, the name can optionally start with & to mean
 6+For the . , : ; commands, the name can optionally start with & to mean
 7 that it is interpreted the same as for a & command.
 8 
 9+Another nonstandard feature is that if you define a macro whose name
10+starts with a character which has a special meaning, then that special
11+meaning is ignored in the rest of the file.
12+
13 
14 === Special calculations ===
15 

 1@@ -59,6 +59,7 @@ static int ssptr;
 2 static Uint16 sstack[256];
 3 static int bsptr,bcnt;
 4 static Uint16 bstack[256];
 5+static char spec_rune[128];
 6 
 7 /* clang-format off */
 8 
 9@@ -329,6 +330,7 @@ parse(char *w, FILE *f)
10 	Label*l;
11 	if(slen(w) >= 63)
12 		return error("Invalid token", w);
13+	if(spec_rune[*w]) goto defa;
14 	switch(w[0]) {
15 	case '(': /* comment */
16 		if(slen(w) != 1) fprintf(stderr, "-- Malformed comment: %s\n", w);
17@@ -347,6 +349,7 @@ parse(char *w, FILE *f)
18 			return error("Invalid include", w);
19 		break;
20 	case '%': /* macro */
21+		spec_rune[w[1]&127]=1;
22 		if(!makemacro(w + 1, f))
23 			return error("Invalid macro", w);
24 		break;