Added a header for text handling in ascii

include/gp/text/ascii.hpp

@@ -0,0 +1,13 @@
+#pragma once
+
+inline bool is_digit(char v) {
+    return v >= '0' && v <= '9';
+}
+
+inline bool is_alpha(char v) {
+    return (v >= 'a' && v <= 'z' )||(v >= 'A' && v <= 'Z');
+}
+
+inline bool is_alnum(char v) {
+    return is_alpha(v) || is_digit(v);
+}