/**
* Evaluates the replace function.
*
* @param val input value
* @param ctx query context
* @return function result
* @throws QueryException query exception
*/
private Item replace(final byte[] val, final QueryContext ctx) throws QueryException {
final byte[] rep = checkStr(expr[2], ctx);
for (int i = 0; i < rep.length; ++i) {
if (rep[i] == '\\') {
if (i + 1 == rep.length || rep[i + 1] != '\\' && rep[i + 1] != '$') FUNREPBS.thrw(info);
++i;
}
if (rep[i] == '$'
&& (i == 0 || rep[i - 1] != '\\')
&& (i + 1 == rep.length || !digit(rep[i + 1]))) FUNREPDOL.thrw(info);
}
final Pattern p = pattern(expr[1], expr.length == 4 ? expr[3] : null, ctx);
if (p.pattern().isEmpty()) REGROUP.thrw(info);
String r = string(rep);
if ((p.flags() & Pattern.LITERAL) != 0) {
r = SLASH.matcher(BSLASH.matcher(r).replaceAll("\\\\\\\\")).replaceAll("\\\\\\$");
}
try {
return Str.get(p.matcher(string(val)).replaceAll(r));
} catch (final Exception ex) {
if (ex.getMessage().contains("No group")) REGROUP.thrw(info);
throw REGPAT.thrw(info, ex);
}
}
