Clarified parsing of hex as unsigned in fromHexDigits methods.

Author: RogerRiggs

src/java.base/share/classes/java/util/HexFormat.java

@@ -927,7 +927,8 @@ private int fromHexDigits(CharSequence string, int index) {
     /**
      * Returns the {@code int} value parsed from a string of up to eight hexadecimal characters.
      * The hexadecimal characters are parsed from most significant to least significant
-     * using {@link #fromHexDigit(int)}.
+     * using {@link #fromHexDigit(int)} to form an unsigned value.
+     * The value is zero extended to 32 bits and is returned as an {@code int}.
      * The delimiter, prefix, suffix, and uppercase parameters are not used.
      *
      * @apiNote
@@ -957,7 +958,9 @@ public int fromHexDigits(CharSequence string) {
      * Returns the {@code int} value parsed from a string range of up to eight hexadecimal
      * characters.
      * The characters in the range {@code fromIndex} to {@code toIndex}, exclusive,
-     * are parsed from most significant to least significant using {@link #fromHexDigit(int)}.
+     * are parsed are parsed from most significant to least significant
+     * using {@link #fromHexDigit(int)} to form an unsigned value.
+     * The value is zero extended to 32 bits and is returned as an {@code int}.
      * The delimiter, prefix, suffix, and uppercase parameters are not used.
      *
      * @apiNote
@@ -991,7 +994,9 @@ public int fromHexDigits(CharSequence string, int fromIndex, int toIndex) {
     /**
      * Returns the long value parsed from a string of up to sixteen hexadecimal characters.
      * The hexadecimal characters are parsed from most significant to least significant
-     * using {@link #fromHexDigit(int)}.
+     * using {@link #fromHexDigit(int)} to form an unsigned value.
+     * The value is zero extended to 64 bits and is returned as a {@code long}.
+
      * The delimiter, prefix, suffix, and uppercase parameters are not used.
      *
      * @apiNote
@@ -1021,7 +1026,9 @@ public long fromHexDigitsToLong(CharSequence string) {
      * Returns the long value parsed from a string range of up to sixteen hexadecimal
      * characters.
      * The characters in the range {@code fromIndex} to {@code toIndex}, exclusive,
-     * are parsed from most significant to least significant using {@link #fromHexDigit(int)}.
+     * parsed from most significant to least significant
+     * using {@link #fromHexDigit(int)} to form an unsigned value.
+     * The value is zero extended to 64 bits and is returned as a {@code long}.
      * The delimiter, prefix, suffix, and uppercase parameters are not used.
      *
      * @apiNote