Comment by imron
11 years ago
Not defending javascript because I dislike it immensely, but with javascript being a dynamically typed language, and with the way it handles implicit conversions between types, and with trickiness around NaN, Infinity and null objects, there are sufficient edge cases that writing a correct function to test if some variable contains a positive integer is not as trivial as it is with more sane languages, and is likely to trip up even experienced developers if they miss one or more of those edge cases.
Having pre-written modules that account for all edge cases that have been battle-tested by hundreds, thousands, or even millions of users does have merit.
The main problem here is with the Javascript language, which makes code evolve to things like 'is-positive-integer'.
(That's the whole point of using a dynamic language, what '>' actually does depends on the surrounding code. If you want '>' to type check you should be using a type safe language to begin with.)
The issue I have with this is readability. Type '>' and I know exactly what it does, I know what implicit conversions are involved, and how it would react to a null object. Type 'isPositiveInteger' and I need to check. I can not read your code fluently anymore.
What if sometimes I want the overloaded, type relevant '>', and sometimes I want to do '>' if the inputs are positive integers, and raise an exception otherwise?