Question

Is there a better (more eloquent) way to check for valid params?

def load_data filename, start_percent, end_percent
  raise 'Values must be [0,1]' if start_percent < 0
  raise 'Values must be [0,1]' if end_percent   < 0
  raise 'Values must be [0,1]' if start_percent > 1
  raise 'Values must be [0,1]' if end_percent   > 1
  ...

Ruby 1.9.3

EDIT: start_percent and end_percent are supposed to be floats.

Answer 1

When this error happens, you’ll want to know the details (what kind of error, what argument, what invalid value):

def load_data filename, start_percent, end_percent
  raise ArgumentError, "start_percent must be [0,1]; received #{start_percent}." unless start_percent.between?(0, 1)
  raise ArgumentError, "end_percent must be [0,1]; received #{end_percent}." unless end_percent.between?(0, 1)
end