Char.isLetter and Char.isLetterOrDigit (JVM).

libraries/stdlib/src/kotlin/text/CharJVM.kt

@@ -21,6 +21,16 @@ package kotlin
  */
 public fun Char.isDefined(): Boolean = Character.isDefined(this)
 
+/**
+ * Returns `true` if this character is a letter.
+ */
+public fun Char.isLetter(): Boolean = Character.isLetter(this)
+
+/**
+ * Returns `true` if this character is a letter or digit.
+ */
+public fun Char.isLetterOrDigit(): Boolean = Character.isLetterOrDigit(this)
+
 /**
  * Returns `true` if this character (Unicode code point) is a digit.
  */