private Filter parseExpression(String filterExpression) {
// expressions handled for the moment: (informal grammar)
// EXP := SIMPLE_EXP | AND_EXP | OR_EXP | NOT_EXP
// AND_EXP := EXP && EXP
// OR_EXP := EXP || EXP
// NOT_EXP := ! EXP
// SIMPLE_EXP := attname = comma, separated, list, of, accepted, values
// example: organisation = foo && module = bar, baz
filterExpression = filterExpression.trim();
int index = filterExpression.indexOf(AND);
if (index == -1) {
index = filterExpression.indexOf(OR);
if (index == -1) {
if (filterExpression.startsWith(NOT)) {
return new NotFilter(parseExpression(filterExpression.substring(NOT.length())));
} else {
index = filterExpression.indexOf("=");
if (index == -1) {
throw new IllegalArgumentException(
"bad filter expression: " + filterExpression + ": no equal sign found");
}
final String attname = filterExpression.substring(0, index).trim();
String[] values = filterExpression.substring(index + 1).trim().split(",");
final Matcher[] matchers = new Matcher[values.length];
for (int i = 0; i < values.length; i++) {
matchers[i] = matcher.getMatcher(values[i].trim());
}
return new Filter() {
public boolean accept(Object o) {
IvyEvent e = (IvyEvent) o;
String val = (String) e.getAttributes().get(attname);
if (val == null) {
return false;
}
for (int i = 0; i < matchers.length; i++) {
if (matchers[i].matches(val)) {
return true;
}
}
return false;
}
};
}
} else {
return new OrFilter(
parseExpression(filterExpression.substring(0, index)),
parseExpression(filterExpression.substring(index + OR.length())));
}
} else {
return new AndFilter(
parseExpression(filterExpression.substring(0, index)),
parseExpression(filterExpression.substring(index + AND.length())));
}
}
