diff --git a/core/include/fxcrt/fx_ext.h b/core/include/fxcrt/fx_ext.h
index 6cba8ee..3f4f668 100644
--- a/core/include/fxcrt/fx_ext.h
+++ b/core/include/fxcrt/fx_ext.h
@@ -36,6 +36,15 @@
 inline int32_t FXSYS_toupper(int32_t ch) {
   return ch < 'a' || ch > 'z' ? ch : (ch - 0x20);
 }
+inline FX_BOOL FXSYS_iswalpha(wchar_t wch) {
+  return (wch >= L'A' && wch <= L'Z') || (wch >= L'a' && wch <= L'z');
+}
+inline FX_BOOL FXSYS_iswdigit(wchar_t wch) {
+  return wch >= L'0' && wch <= L'9';
+}
+inline FX_BOOL FXSYS_iswalnum(wchar_t wch) {
+  return FXSYS_iswalpha(wch) || FXSYS_iswdigit(wch);
+}
 
 inline int FXSYS_toHexDigit(const FX_CHAR c) {
   if (!std::isxdigit(c))