Starting ALU

src/modal.c

@@ -31,10 +31,30 @@ walk(char *s)
 	return s;
 }
 
+static int
+sint(char *s)
+{
+	int acc = 0;
+	char c;
+	while((c = *s++) && c > 0x20) acc *= 10, acc += c - '0';
+	return acc;
+}
+
 static void
 device_write(char *s)
 {
-	char c, *cap = walk(s);
+	int acc = 0;
+	char c = *s, *cap = walk(s), *reg = regs['0'];
+	if(reg) {
+		switch(c) {
+		case '+':
+			for(acc = sint(reg++); *reg; reg++) acc = acc + sint(reg);
+			break;
+		}
+		dst_ += snprintf(dst_, 0x10, "%d\n", acc);
+		return;
+	}
+
 	if(*s == '(') s++, --cap;
 	while(s < cap) {
 		c = *s++;