@@ -88,9 +88,25 @@
 		if !n.Matched {
 			return n, s
 		}
 		if n.Content == value {
 			return n, r
+		}
+		return N{Matched: false, Content: "", Nodes: []N{n}}, s
+	}
+}
+
+// Returns a parser that matches any single digit
+// It could have been written as Any(String("0"),String("1"),...,String("9")) as well :)
+func Digit() P {
+	accept := Accept(1)
+	return func(s string) (N, string) {
+		n, r := accept(s)
+		if !n.Matched {
+			return n, s
+		}
+		if n.Content[0] >= 48 && n.Content[0] <= 57 {
+			return n, r
 		}
 		return N{Matched: false, Content: "", Nodes: []N{n}}, s
 	}
 }