What the F#

Perl not included in list.

Conclusion: In Perl, everything works as expected

Correction: In Perl, everything works as can be expected.
I'll share with you this gem from someone who tried to cause a syntax error on purpose, but the script ran just fine: https://stackoverflow.com/questions/11695110/why-is-this-program-valid-i-was-trying-to-create-a-syntax-error

I love that the contribute is just a mailto link. I want to see more of this & less “join the Discord chatroom & create a Microsoft GitHub account today”

Python item 1

Mutable default arguments don't get re-initialized with each function call.

got an audible wtf from me... Been using python for years, totally unaware.

Mutating function arguments is pretty wtf to begin with.
- true, and i can't think of a legitimate case where it would have tripped me up. but if someone, a novice perhaps, wrote
  
  def some_func(foo, bar=[1, 2, 3]): bar.reverse() # for whatever reason print(bar) some_func('hello') # output [3,2,1] some_func('hello') # output [1,2,3]
  
  i think they would be within their rights to be surprised that calling this function twice has different results. that's what i was surprised by; it feels like bar would be re initialised each time with a scope of the function but apparenty not

Not only funny, but also learned something today: you can use NegativeLiterals to not have to write (-123) in Haskell

The WTF in the C# example seems to be that people don't understand anonymous functions and closures?

Some of the examples seem to be more "unintuitive for newbies", but there are still some good ones in there
- Yeah, just check the PHP section!
  
  My favourite is
  
  var_dump(true == 'bob') . PHP_EOL; // bool(true) var_dump('bob' == 0) . PHP_EOL; // bool(true) var_dump(true == 0) . PHP_EOL; // bool(false)
Yeah. I didn't understand what they meant by the wtf there. Seemed to me someone wondered if the Action would have a localised version of i (making this stay lowercase on a phone was harder than it should be) or if it used the same i. So made a simple test for it.

Not really sure it's a wtf unless they expected a different result.
- I think the explanation they provide is a bit lacking as well. Defining an anonymous function doesn't "create a reference" to any variables it uses, it captures the scope in which it was defined and retains existing references.
Go had the same behavior until recently. Closures captures the variable from the for loop and it was a reference to the value.
They changed it because it's "common" in Go to loop over something and run a goroutine that uses the variable defined in the loop. Workaround was to either shadow the variable with itself before the loop, or to pass the value as an argument.
It's been a long time since I wrote c# so idk if the same is expected from the avg dev, but in Go it's really not explicit that the variable will be a reference instead of a plain value
- i is still a value type, that never changes. Which highlights another issue I have with the explanation as provided. Using the word "reference" in a confusing way. Anonymous methods capture their enclosing scope, so i simply remains in-scope for all calls to those functions, and all those functions share the same enclosing scope. It never changes from being a value type.

Are we supposed to be able to scroll through the examples? Also, it's odd to see expected behavior in there.

The C# example works exactly as you'd expect.. Actually most of them do
- The compiler optimization example (IIRC #6) was unexpected, when just looking at the code
Make sure, you're not blocking fontawesome.com in NoScript or whatever content blocker you might be using. All the UI buttons depend on that to be available...
- I'm raw-dogging Chrome and Android and there are no navigation controls, just the dropdown and reveal.

Enjoyed this :D

In relational databases (sql) tables are actually table representations of relations, where a relation is defined as any subset of a Cartesian product.

In the first sql example we have a "person" relation, which is a subset of namesXgenders cartesian product. Because of this an element of the person relation ("Jimothy", null) cannot have "no gender" (as it wouldn't be a member of the cartesian product namesXgenders).

All of this leads to the following: null in sql doesn't mean "said element doesn't have that property", it means that said property is unknown.

With that in mind, the first example returns expected, if on the surface counterintuitive result: you don't know what Jimothy 's gender is, so when queried with NOT M NOT F, that row shouldn't be returned, because you can't just assume Jinothy's gender. The query should be, for those cases: not m, not f or unknown (ie is null).

Similarly for the second case. Email is not nonexistent, it's unknown, so it makes sense that the db allows you to insert more than one person with unknown email addresses.

I wouldn't say that either of these is an sql wtf, I would just call both of those tables badly designed.

For Haskell:

I'd say this is definitely a wtf. Tuples should have never been given Foldable instances and I'd immediately reject any code that uses it in code review.
I actually didn't know, so TIL. Not surprising since common wisdom is that a lot of the type class instances for Doubles are pretty weird/don't make a lot of sense. Just like in any language, floating point needs special care.
This is jjust expected syntax and not really a wtf at all. It's very common for languages to require whitespace around operators.
Agreed as wtf, the NegativeLiterals should be on by default. Just would be a pretty significant breaking change, unfortunately
Not a wtf... What would you expect to happen? That operation is not well-defined in any language

Powershell is not on the list...

I am not a programmer, but a sysadmin. Don't get to enjoy this one :-\

If you have some good PowerShell examples, feel free to contribute them, I'm sure they'd be welcome

No rust?

Guess that proves it's the best programming language with absolutely zero edge cases! /s