?~ register now takes in an argument

examples/adventure.modal

@@ -1,9 +1,9 @@
 <> ((You said: quit\n) send) ((You quit.) print ')
 <> (?: print ') (?:)
-<> (?: send) (?: wait)
-<> (wait) ((You said: ?~\n) send)
+<> (?: send) (?: wait stdin)
+<> (wait ?~) ((You said: ?~\n) send)
 <> (' ?x) (?x ')
 
 (Say something, or type "quit": \n) print '
 
-wait
+wait stdin

examples/hello.modal

@@ -1,5 +1,4 @@
-<> (NAME) (Modal)
-<> (?: print $) (?:)
-<> ($ ?x) (?x $)
 
-$ (Welcome to NAME \nHave fun!\n\n) print
+<> (listen ?~) (?~ done.)
+
+foo listen stdin bar

examples/tictactoe.modal

@@ -1,7 +1,7 @@
 -- (Tic Tac Toe)
 
 <> (-- ?x) ()
-<> (READ) (?~)
+<> (READ ?~) (?~)
 
 -- (Print)
 
@@ -34,8 +34,8 @@
 
 -- (Play)
 
-<> (ready) (display READ play)
-<> (?x run wait) (READ play)
+<> (ready) (display READ stdin play)
+<> (?x run wait) (READ stdin play)
 <> (?x victory) ((?x wins!\n) put-str)
 
 -- (Interface)

src/modal.c

@@ -45,29 +45,24 @@ set_reg(int r, char *b)
 static void
 put_reg(char r)
 {
-	char c, *s = regs[(int)r];
-	if(r == '~') {
-		/* special stdin */
-		while(fread(&c, 1, 1, stdin) && c >= ' ')
-			*outp_++ = c;
-	} else if(s) {
-		char *ss = walk(s);
+	char c, *s = regs[(int)r], *ss;
+	if(!s) {
+		*outp_++ = '?', *outp_++ = r;
+		return;
+	}
+	*ss = walk(s);
 	if(r == '*') {
-			/* special implode */
-			if(*s == '(') {
+		if(*s == '(') { /* special implode */
 			while(s < ss && (c = *s++))
 				if(!spacer(c)) *outp_++ = c;
-			}
-			/* special explode */
-			else {
+		} else { /* special explode */
 			int i, depth = 0;
 			while((c = *s++) && !spacer(c))
 				*outp_++ = c, *outp_++ = ' ', *outp_++ = '(', depth++;
 			for(i = 0; i < depth; i++)
 				*outp_++ = ')';
 		}
-		} else if(r == ':') {
-			/* special stdout */
+	} else if(r == ':') { /* special stdout */
 		if(*s == '(') s++, --ss;
 		while(s < ss) {
 			c = *s++;
@@ -80,10 +75,11 @@ put_reg(char r)
 			} else
 				putc(c, stdout);
 		}
+	} else if(r == '~') { /* special stdin */
+		while(fread(&c, 1, 1, stdin) && c >= ' ')
+			*outp_++ = c;
 	} else
 		while(s < ss) *outp_++ = *s++;
-	} else
-		*outp_++ = '?', *outp_++ = r;
 }
 
 static char *