/**
* Removes leading and trailing whitespaces from the specified token.
*
* @param token token to be trimmed
* @return trimmed token
*/
public static byte[] trim(final byte[] token) {
int s = -1;
int e = token.length;
while (++s < e) if (token[s] > ' ' || token[s] < 0) break;
while (--e > s) if (token[e] > ' ' || token[e] < 0) break;
if (++e == token.length && s == 0) return token;
return s == e ? EMPTY : Arrays.copyOfRange(token, s, e);
}
/**
* Returns a partial token.
*
* @param token input text
* @param start start position
* @param end end position
* @return resulting text
*/
public static byte[] subtoken(final byte[] token, final int start, final int end) {
int s = Math.max(0, start);
final int e = Math.min(end, token.length);
if (s == 0 && e == token.length) return token;
if (s >= e) return EMPTY;
int t = Math.max(0, s - 4);
for (; t != s && t < e; t += cl(token, t)) {
if (t >= s) s = t;
}
for (; t < e; t += cl(token, t)) ;
return Arrays.copyOfRange(token, s, t);
}
/**
* Returns a substring of the specified token. Note that this method does not correctly split UTF8
* character; use {@link #subtoken} instead.
*
* @param token input token
* @param start start position
* @param end end position
* @return substring
*/
public static byte[] substring(final byte[] token, final int start, final int end) {
final int s = Math.max(0, start);
final int e = Math.min(end, token.length);
if (s == 0 && e == token.length) return token;
return s >= e ? EMPTY : Arrays.copyOfRange(token, s, e);
}