[Array access detection] Refactor function that collects candidates.

[mari-mari]

Proposal

Pure free-time refactoring issue, originated from some merge request review. One could make the function that collects candidates prettier.

Approach

Something like this could potentially work:

if candidate := self.get_array_access_candidate(candidate):
    self._candidates[base].append(candidate)
    self._update_candidate_offsets(base, offset_class, element_size)

def get_array_access_candidate(candidate) -> Optional[Candidate]:
  operand = candidate.operand
  if not self._is_addition(operand):
    return None
  base, offset = self._get_base_and_offset(operand)
  if not (base and offset):
    return None
  offset_class, index, element_size = self._parse_offset(offset)
  return Candidate(candidate, index, base)

Should be tested, if it works like this.