[MATH-337] Equals methods rely on catching ClassCastException rather than using instanceof check

• Type: Improvement
• Status: Closed
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: 2.0
• Fix Version/s: 2.1
• Assignee: Unassigned
• Reporter: Sebb
• Created: 27/Jan/10 15:57
• Updated: 03/Apr/10 03:55
• Resolved: 14/Mar/10 01:27

Description

Several of the equals methods rely on catching ClassCastException rather than using an instanceof check.

For example:

SimplexTableau.equals(Object){
  if (this == other) {
    return true;
  }
  if (other == null) {
    return false;
  }
  try {
      SimplexTableau rhs = (SimplexTableau) other;
      etc.
  } catch (ClassCastException ex) {
      return false;
  }
}

This is likely to be significantly slower if the cast fails. It would be cheaper to do the following:

SimplexTableau.equals(Object){
  if (this == other) {
    return true;
  }
  if (!(other instanceof SimplexTableau)) {
    return false;
  }
  SimplexTableau rhs = (SimplexTableau) other;
  etc.
}

Note that the null check is no longer needed; it is replaced by the instanceof check.