I have a method to find the position of an operator.
public Optional<Integer> findToken(Character operator) {
return tokenList.stream()
.filter(x -> {
return x.position >= startPosition &&
x.position <= endPosition &&
x.operator == operator;
})
.findFirst()
.map(t -> t.position);
}
Instead of passing a single operator, i would like to pass a few different operators each time. I have appended the operator list onto an array. Is there a way to use the JOIN operator or For each syntax to loop through the list and find the position.
Answer
I am not sure why you would use JOIN of forEach(), but here is a solution using Set.contains():
public List<Integer> findTokens(Character operators[]) {
Set<Character> set = new HashSet<>();
set.addAll(Arrays.asList(operators));
return tokenList.stream()
.filter(x -> {
return x.position >= startPosition &&
x.position <= endPosition &&
set.contains(x.operator);
})
.map(t -> t.position)
.collect(Collectors.toList());
}