On: Reducing Code Nesting

[emehrkay]

Does anyone else hate multiple returns?

A do/while condition would satisfy this situation. or while True: if False: break in python

[prophetjohn → emehrkay]

It depends on the compactness of the code. If it's a large function, I try to avoid it, but 100% adherence to "one entry, one exit" kind of misses the spirit of the idiom. Something like:

    if (condition)
      return true;
    return false;

is no less readable and sometimes more intuitive than the equivalent

    bool x = false;
    if (condition)
      x = true;
    return x;

[marshray → prophetjohn]

How about this:

   return condition;

[ceol → marshray]

I'm certain he was using True and False as arbitrary values. It's a shame his point was missed. Please try to focus on his actual argument.

[marshray → ceol]

I'm not so convinced that it's not a fundamental thing.

Maybe someone wants to post a 'better' example and we'll see where it goes?

[ceol → marshray]

How about:

    if (condition())
        return 10;
    return 20;

versus

    val = 20;
    if (condition())
         val = 10;
    return val;

[pka → ceol]

Well:

    val = condition() ? 20 : 10;
    return val;

[jonathanwallace → pka]

Did you invert the logic of the parent post on purpose?

[marshray → pka]

Or even:

    return condition() ? 10 : 20;

[prophetjohn → marshray]

Yeah, that's definitely a more reasonable way to implement the above example. I didn't put much thought into the specifics of the code, since the specifics have nothing to do with what point I was making. I was responding to a question about multiple returns; the simple example was supposed to illustrate my opinion on multiple returns, not how to return a boolean value given a boolean condition.

[perfunctory → prophetjohn]

if `if` was an expression rather than a statement one could write

return if condition() 10 else 20

I am not sure this is more readable though.

[marshray → perfunctory]

There is an 'if' expression, it's just spelled '?' and else is ':'. Mentioned a few posts up.

[marshray → emehrkay]

Yes. I generally try to avoid them in my code, unless doing so makes the logic significantly more contorted and then I put a prominent comment way out on the right margin to draw attention to the inner return.

That first get_cached_user example probably doesn't need to be nested. I don't know about Python but I would expect an optimizing compiler to short circuit the redundant conditionals if it really mattered. If it really did matter for performance, the aesthetics become a distant second consideration.

I don't see anything wrong with the get_media_details example, other than perhaps the logic of the example itself. It looks readable to me, but a blank line after 9, 13, and 19 would help with readability. If it were to grow more complicated I might look at refactoring using some sort of object polymorphism.

To me the only thing worse than complex deeply-nested control structures is code that tries to hide that complexity for aesthetic reasons in control structures that are only superficially simpler.

[johnx123-up → emehrkay]

I strongly hate multiple returns. OTOH, I wish python had curly braces.