/**
* Creates a multi expression from a list of expressions, removing expressions that do not have
* side effects if possible.
*/
public static JExpression createOptimizedMultiExpression(
boolean ignoringResult, List<JExpression> expressions) {
int numberOfExpressions = expressions.size();
JExpression result = expressions.get(numberOfExpressions - 1);
numberOfExpressions = expressions.size();
if (numberOfExpressions == 0) {
return new JMultiExpression(SourceOrigin.UNKNOWN);
}
expressions =
Lists.newArrayList(
Collections2.filter(
expressions.subList(0, numberOfExpressions - 1),
Predicates.and(
Predicates.notNull(),
new Predicate<JExpression>() {
@Override
public boolean apply(JExpression expression) {
return expression.hasSideEffects();
}
})));
if (result != null && (!ignoringResult || result.hasSideEffects())) {
expressions.add(result);
}
if (expressions.size() == 1) {
// Do not create a multi expression if it consists only of the result.
return expressions.iterator().next();
}
SourceInfo info =
expressions.size() > 0 ? expressions.get(0).getSourceInfo() : SourceOrigin.UNKNOWN;
return new JMultiExpression(info, expressions);
}
