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Title
b

bod

12/28/2017, 6:00 PM
you should know better than the compiler 🙂
😂 1
j

jkbbwr

12/28/2017, 6:10 PM
No you shouldn't compilers are better at problem solving than humans when the problem is defined properly.
k

karelpeeters

12/28/2017, 6:11 PM
Something something dynamically typed languages 😛.
b

bod

12/28/2017, 6:12 PM
A compiler is a very basic tool. The human brain of a developer is smarter. Jetbrains knew this when they specified Kotlin and decided
!!
would be useful 🙂
Same with annotations or other mechanisms that allow to ignore warnings. Because a developer is smarter than a static analysis tool.
s

Shawn

12/28/2017, 6:19 PM
just because the compiler generate warnings that aren’t appropriate in 100% of all edge cases doesn’t mean developers are smarter
humans make plenty of mistakes and misinterpret things literally all the time
really “smarter” isn’t a useful term here since it implies we’re talking about more general-purpose kind of intelligence. in a restricted domain with a properly defined problem space (crazy example: compiling a programming language), the machine will get it wrong far less than the person will
c

cedric

12/28/2017, 9:38 PM
Even if occasionally I know for sure something can't be
null
but the compiler doesn't, I'll throw in a
null
test
else
throw some exception
k

karelpeeters

12/28/2017, 9:41 PM
That's basically the same as
!!
though.
c

cedric

12/28/2017, 9:42 PM
Except I can make the exception more meaningful
If I feel really confident, I'll just
?.let { nonNullableVal
but I'm always a bit wary of
?.let
because it's an
if
without an
else
, and this has the potential to hide bugs
2
g

groostav

12/29/2017, 2:08 AM
we've got a couple of objects on our code-base that are used in such a way where they may have nullable fields and then at some point our business logic means that those fields cant be null. most of the time, similar to cerdric, I'll throw a
require(we.someProp != null) { "msg with domain significance" }
infront of the methods in question. validation on a POJO (data-class) seems to be a pretty obvious example. If you've got a validator and a service that expects only objects passed by the validator, and you dont want to map from a nullable-POJO to a non-nullable one your service is likely to be implemented with some
pojo.someProperty!!
.
1
g

gildor

12/29/2017, 2:38 AM
require(we.someProp != null)
->
requireNotNull(we.someProp)
2
b

bod

12/29/2017, 10:03 AM
Regardless of what "smart" means, really my point was that I don't think
!!
should be considered a code smell 🙂 Sometimes you just know with 100% certainty that a variable cannot be null, and testing its nullity will add noise (and possible confusion) to the code - that's when
!!
does absolutely make sense, and should be encouraged 🙂 Well that's my personal opinion about it anyway and I can understand if some people disagree 🙂
1