kotlinlang #announcements

The main reason to not use hash code to verify if an object changed is that hash code might not capture all the fields that this object maintains, only the ones that participate in that object's id

danielspeixoto

11/19/2017, 9:11 PM

Does anyone knows where can I find stats about Kotlin growing rate among programmers?

Shawn

11/19/2017, 9:16 PM

@danielspeixoto I think @thomasnield was looking for that kind of data a little while ago

Shawn

11/19/2017, 9:16 PM

might be worth pinging him for resources

danielspeixoto

11/19/2017, 9:16 PM

Thanks @Shawn

dave08

11/19/2017, 9:29 PM

Just look at the number of members on this channel! 😁

nfrankel

11/20/2017, 9:49 PM

hey guys i’m searching for the equivalent of the

.?

operator but for collections which are/are not empty any hint?

ebonet

11/20/2017, 9:50 PM

i don’t think it exists

kevinmost

11/20/2017, 9:51 PM

list.takeIf { it.isNotEmpty }

kevinmost

11/20/2017, 9:51 PM

makes it null if it's empty

kevinmost

11/20/2017, 9:51 PM

alternatively,

list.takeUnless { it.isEmpty }

nfrankel

11/20/2017, 9:51 PM

this is my existing snippet:

Copy code

return when (response.resultsCount) {
    0 -> "No match found, try again"
    else -> {
        val speechRecognitionResult = response.resultsList[0]
        when (speechRecognitionResult.alternativesCount) {
            0 -> "No match found, try again"
            else -> speechRecognitionResult.alternativesList[0].transcript
        }
    }
}

nfrankel

11/20/2017, 9:51 PM

@kevinmost thanks, i’ll try to check if it’s more readable

ebonet

11/20/2017, 9:52 PM

why no using it in regular form?

ebonet

11/20/2017, 9:52 PM

Copy code

if (response.resultsCount == 0)    return "No match found, try again"
val speechRecognitionResult = response.resultsList[0];
if( speechRecognitionResult.alternativesCount == 0) return "No match found, try again";

return speechRecognitionResult.alternativesList[0].transcript;

ebonet

11/20/2017, 9:55 PM

alternatively

ebonet

11/20/2017, 9:56 PM

Copy code

if (response.resultsCount == 0 || response.resultsList[0].alternativesCount == 0) return “No match found, try again”;
return response.resultsList[0].alternativesList[0].transcript

nfrankel

11/20/2017, 9:57 PM

i’m trying to find the more readable...

nfrankel

11/20/2017, 9:57 PM

in a kotlin idiomatic way

ebonet

11/20/2017, 9:58 PM

“kotlin idiomatic” is the simplest way, no the way with the fanciest functions IMO

ebonet

11/20/2017, 9:59 PM

isn’t it?

nfrankel

11/20/2017, 10:00 PM

hmmm... not quite agree but i like simple 🙂

ebonet

11/20/2017, 10:01 PM

if resultsList is empty when resultsCount is 0

ebonet

11/20/2017, 10:02 PM

Copy code

if (response.isEmpty() || response.resultsList[0].isEmpty()) return "No match found, try again";
return response.resultsList[0].alternativesList[0].transcript

Shawn

11/20/2017, 10:02 PM

bending

when

to replicate what’s essentially a chained comparison isn’t idiomatic my dude

pavel

11/20/2017, 10:03 PM

There is always https://kotlinlang.org/api/latest/jvm/stdlib/kotlin.collections/first-or-null.html

😀 1

➕ 1

ebonet

11/20/2017, 10:05 PM

Copy code

return response.resultsList.firstOrNull()?.altenartiveList?.firstOrNull()?.transcript ?: "No match found, try again"

🍻 1

ebonet

11/20/2017, 10:06 PM

i would somewhat still prefer the “non-idiomatic” way

ebonet

11/20/2017, 10:06 PM

it looks simpler

Shawn

11/20/2017, 10:06 PM

I mean, maybe don’t do all the navigation in one line