Hi, lets say I have a sequence of objects (for sim...

# functional

[Szymon Sasin]

Hi, lets say I have a sequence of objects (for simplicity I use strings):

val s = sequenceOf("Lorem", "ipsum", "dolor", "sit", "amet")

What’s the best way to limit elements so total size is smaller than desired.
For example:

val s2 = s.someFunction(maxSize = 17) { it.length }
println(s2.toList()) // [Lorem, ipsum, dolor]

[chiroptical]

s.filter { it.length < 17 }?

[chiroptical]

I guess you want total characters in the result list.

[Szymon Sasin]

Yes 😉

[chiroptical]

You could use a fold maintaining like Pair<Sequence<String>, Int> or something?

[Starr]

I think there's a limit(Int) method?
oh nvm you don't want to limit the number of elements. though maybe flatMap{ it.chars.asSequence() }.limit(17) would work? though it wouldn't keep the original strings

[Szymon Sasin]

The idea is to make it work for more generic object (not String), so asSequence does not work.

[ephemient]

var total = 0
val limit = s.indexOfFirst {
    total += it.length
    total > 17
}
val s2 = s.take(if (limit >= 0) limit else s.size)

[ephemient]

or

val s2 = buildList {
    var total = 0
    for (t in s) (
        total += t.length
        if (total > 17) break
        add(t)
    }
}

[Szymon Sasin]

Previous one creates state to a sequence so when run again it will not produce same result. But second example looks good and simple. Thanks.