OpenEuphoria

Re: Should to_number return a sequence?

• Posted by xecronix 6 days ago
• 414 views

It's a little bit of a pickle. to_number, given it's name, should simply return a number. But since 0 is a number, that opens up the door for confusion about the meaning of the return value. I think return values that differ in size and type seems peculiar though. And since try/catch isn't an option...

So, what are options?

• to_number crashes on failure. Valid option. But, without an is_number function, that seems a little unforgiving.
• to_number always returns a sequence. It's debatable about what's in the sequence, but 0 or a failure position in element 1 and a number or 0 in element 2 seems reasonable. Or maybe just 1 or 0 in the first element? Or maybe the first element is a number type? (0=NAN, 1=Integer, 2=Float, 3=Currency maybe?) Then, every call has a consistent return value. The next question is if to_number is a valid name for the function. (maybe parse_num might be better?)
• Do nothing. It's fine the way it is.

hmm... Does to_number have too many valid number formats and/or do too much? IDK, opinions, I guess. I think so. But, there isn't anything stopping someone from writing: (not tested... probably works)

function parse_num(sequence s) 
    atom err = atom(to_number(s), -1) 
    atom val = to_number(s) 
    return {err, val} 
end function 

Or if someone were inclined to be Phix and Euphoria compatible: (also not tested)

function parse_num(sequence s) 
    atom b = is_number(s) -- adopting my is_number function or writing a better one. 
    if b then 
        return {b, to_number(s)} -- maybe return a type checked sequence instead?  worth considering. 
    end if 
    return {b, 0} 
end function