Refactoring: Refactorings/Split Temporary Variable

Temporary variable is assigned, used, then reassigned for another purpose.

Mechanics

1. Change name of temporary variable at its first assignment

   If later assignments are of form i = i + expression, temp variable is "collecting" (addition, concatenation, stream, add to collection)

2. Change all references to the temporary variable up to its second assignment
3. Test
4. Repeat in stages as necessary

Example

Before

def distance_traveled(time)
  acc = @primary_force / @mass                            # First assignment
  primary_time = [time, @delay].min
  result = 0.5 * acc * primary_time * primary_time
  secondary_time = time - @delay
  if secondary_time > 0
    primary_vel = acc * delay
    acc = (@primary_force + @secondary_force) / @mass     # Second assignment
    result += primary_vel * secondary_time + 5 * acc * secondary_time * secondary_time
  end
  result
end

After

def distance_traveled(time)
  primary_acc = @primary_force / @mass
  primary_time = [time, @delay].min
  result = 0.5 * primary_acc * primary_time * primary_time
  secondary_time = time - @delay
  if secondary_time > 0
    primary_vel = primary_acc * delay
    secondary_acc = (@primary_force + @secondary_force) / @mass
    result += primary_vel * secondary_time + 5 * secondary_acc * secondary_time * secondary_time
  end
  result
end