People ITT hating on null coalescing operators need to touch grass. Null coalescing and null conditional (string?.Trim()) are immensely useful and quite readable. One only has to be remotely conscious of edge cases where they can impair readability, which is true of every syntax feature
Languages with null in them at all anymore just irk me. It’s 2023. Why are we still giving ourselves footguns.
You use the language? Weren’t they just for bragging rights and blog posts?
Because languages need to be able to handle the very common edge cases where data sources don’t return complete data.
Adding null coalescing to a null-safe language (like dart) is so much easier to read and infer the risk of handling null than older languages that just panic the moment null is introduced unexpectedly.
For old languages, null coalescing is a great thing for readability. But in general null is a bad concept, and I don’t see a reason why new languages should use it. That, of course, doesn’t change the fact that we need to deal with the nulls we already have.
Who said anything about panicking the minute we encounter incomplete data? Just do what Rust does and, instead of having all types be able to be null, statically enforce that all variables have an initialized value and have a value have a separate type Option<T> which can either be Some(T) or None, and have the compiler not let you access the value inside unless you write code to handle the None case. There are standard library helper functions for common operations like null coalescing and, as you say, panicking when you encounter a null, but you have to explicitly tell the compiler you want to do that by calling myOption.unwrap()
What makes this really cool is that you can have an Option<Option<T>> where Some(None) is not the same as None, so an iterator that signals end of list by returning None can have None elements in it.
Say what you will about the functional programming people but they were spot on with this one. Having an Option monad in place of the ability for null is absolutely the way to go. I’d say it’s the future but Lisp and APL had this figured out in the 60s
My coworker flips his shit every time I include a ternary operator in a PR. He also insists on refactoring any block of code longer than two lines into its own function, even when it’s only used once.
He is not well liked.
He also insists on refactoring any block of code longer than two lines into its own function
Thanks, uncle Bob.
His advice is great for newer programmers. They are taken literally by newer programmers, but the goal is not to force the dogma onto everyone. Maybe that should be more clear before the new people make a fool of themselves. They’ll learn why or how to apply these rules once they get more experience.
I know the episode you’re referring to and the important part is to realize you can use functions names/signatures to convey and structure information about your code, not just as a way to reuse code. This is often misunderstood by newer programmers, self-taught programmers. Your code should be easy to understand so it’s up to us to make it well structured. Functions aren’t only to avoid duplicate code
Sounds like they learned programming from heavily object oriented languages.
As far as ternary operators go, I personally find them less readable than the longer if else format, but with any reasonably modern IDE or git setup that should be just a simple pass of an auto-formatting tool to convert them to the project/team standard. No need for any team friction. That should be automatically handled before it goes to review.
I’m not in a position with a PR process or anything like that (I’m a glorified scripter in over his head where we need a dev team for internal tools) but I struggle with over reliance on functions as well.
To keep from going overboard I always try to evaluate how often the block of code will see re-use (want to eliminate copy/paste and the footgun of forgetting to update a copy somewhere), how useful it would be to maintainers to have that section abstracted away into a black box (so you only have to worry about the part of the code that’s not working instead of the whole damn thing when something breaks), and how likely that block of code may need to be completely replaced later (if it’s separated out into a function, it’s a discrete chunk where we only have to maintain the same input and output formatting and ideally the rest of the program just werks).
And no one on his team ever understood his code.
Sometimes being declarative is better than being “smart”
The last panel is infinitely more readable than parsing the whole chunk of logic above. Maybe you’re just not used to this language’s (I think this meme used C#) null operators.
Yeah, I have very little programming experience, and even not knowing the code, I figured this one out. Super simplified and clear.
I’m confused on how this is difficult to understand. Put aside the fact that it’s just a regular operator that… I mean virtually everyone should know, how hard is it to google “what does ?? mean in [language]” which has the added benefit of learning a new operator that can clean up your code?
Well yeah but imagine you had to do that on most lines of the code? It would become very distracting imho. If you are in a team with people that have a lot experience and or will learn more anyway this is fine. But if you are in a team with not very good programmers which “will never learn” because they have other stuff to do, you should be careful when using code like this. Though I would prefer in the former of course.
Honestly, and I mean this sincerely, if you’re on a team where the nullable coalesce is going to be confusing after the first handful of times encountered… look for a new job. It doesn’t bode well for their ability to do their jobs.
This is like the guy at Walmart who needs hand holding each time they clean a machine, it’s a problem waiting to happen.
If condition then this else that vs this ?? that
Which option do you think requires less time for a person to identify and understand?
Sure if it’s just your own code do whatever comes natural to you but there’s a reason we don’t use these kind of logical operators in day to day speech is my point.
Ive been a backend dev for 2 years now and I’ve never come across the ?? operator and every time I come across a ternary operator I have to Google in what order comes what.
Not saying it doesn’t make the code more concise and less “noisy” but sometimes a simple if else statement just makes the code easier to mantain
This is why I usually don’t comment on stuff like this in PRs. If it’s readable and easy to understand it doesn’t need more abstractions. Even if it’s less code. What’s it save like a few bytes? That’s not as useful as the whole team instantly knowing how the code works when they see it lol
I will say though if a jr dev came upon the last code they would just look it up and learn something so that’s a total valid path too. Just depends on your codebase and how your team works. I think it usually ends up being a mix with larger teams.
There’s more to it imho. The first three are more prone to mistakes than the last. You are much less likely to accidentally alter the logic intended in a simple null coalesce than you are in if statements.
That’s fair but if you had proper test coverage there wouldn’t be much risk. Who has that though? Lol
Ruby:
a || b
(no return as last line is returned implicitly, no semicolon)
EDIT: As pointed out in the comments, this is not strictly equivalent, as it will return b if a is false as well as if it’s nil (these are the only two falsy values in Ruby).
Python:
return a or b
i like it because it reads like a sentence so it somewhat makes sense
and you can make it more comprehensive if you want to:
return a if a is not None else b
I personally dislike this because when you read “or” you expect some boolean result not a random object :/
For newer python people, they see return a or b and typically think it returns a boolean if either is True. Nope. Returns a if a is truthy and then checks if b is truthy. If neither are truthy, it returns b.
Returns a if a is truthy and then checks if b is truthy. If neither are truthy, it returns b.
Not quite. If a is not truthy, then the expression a or b will always return b.
So, there is never any reason to check the truthiness of b.
you can paste this in your repl to confirm it does not.
class C:
def __repr__(self): return [k for k, v in globals().items() if v is self][0]
def __bool__(self):
print(f"{self}.__bool__() was called")
return False
a, b = C(), C()
print(f"result: {a or b}")
output
a.__bool__() was called
result: b
This doesn’t work for booleans because false is not null but also not truthy. One of things I hate about ruby is that it doesn’t have a native null coalescing operator.
Yeah, you’re quite correct, it’s not exactly equivalent, I just went on auto-pilot because it’s used so much for that purpose 🤖
It’s much closer to being a true null-coalescing operator than ‘OR’ operators in other languages though, because there’s only two values that are falsy in Ruby: nil and false. Some other languages treat 0 and "" (and no doubt other things), as falsy. So this is probably the reason Ruby has never added a true null-coalescing operator, there’s just much fewer cases where there’s a difference.
It’s going to drive me mad now I’ve seen it, though 😆 That’s usually the case with language features, though, you don’t know what you’re missing until you see it in some other language!
Perl has both $a || $b and $a // $b.
The || version is older and has the value of if is any false value including undef (which is pretty much Perl’s null/nil).
The // version has the value of iff is undef. Other “false” values carry through.
Ruby took both “no return required” and “no final semicolon required” from Perl (if not a few other things), I think, but it seems that // was Perl later borrowing Ruby’s || semantics. Interesting.
i.e. 0 || 1 is 1 in Perl but 0 in Ruby. Perl can 0 // 1 instead if the 0, which is a defined value, needs to pass through.
I enjoy this:
return a.or(b);
But yeah, that requires an Option type rather than null pointers…
Is that Rust? Assuming a is an Option (which would be close approximation of OP’s nullable type) and assuming b is not null, then this would be closer to the original idea:
a.unwrap_or(b)
It returns value of a if it’s not None rather than Option.
Ah, true. Thanks.
Theoretically, it was supposed to be pseudo-code, secretly inspired by Rust, but I did get that one mixed up.
And I am actually even a fan of the word unwrap there, because it follows a schema and you can have your IDE auto-complete all the things you can do with an Option.
In many of these other languages, you just get weird collections of symbols which you basically have to memorize and which only cover rather specific uses.
