can takeif be used instead of a normal if else in ...

# announcements

[xii]

can takeif be used instead of a normal if else in the following code somehow?

[xii]

function foo() = if (condition) foo.filter{} else foo

[xii]

i think i've seen it used somehow to decide whether to run the next inline function or not, but i can't remember

[pedro]

foo.takeIf { !condition } ?: foo.filter{...}

[Nir]

i thought takeIf takes a predicate

[Nir]

you probably need braces instead of parens?

[pedro]

that’s right. Do { } around it.

but it doesn’t look great, at least in this small example

(updated the code example)

[xii]

sometimes i wonder where traditional ifs are a better fit

[xii]

thank you 🙂

[Nir]

Well, if you have both if and else branches

[Nir]

then it seems to me not obvious that takeIf/takeUnless will be an improvement

[Nir]

if you just have an if then it's simpler

[pedro]

yeah, whenever I try to use takeIf, I think I end up undoing it. Partly because it’s not a common construct so present/future readers would find it a bit awkward to understand

[Nir]

yeah, it seems liek for simply cases where you already have a variable, all you're doing is replacing one branching construct (if-else) with two (takeIf + ?:)

[Nir]

For me it seems more useful when the condition is complex, and might even involve intermediate variables that have no other use

[Tim VanFosson]

note that if the condition isn't true you're still going to evaluate it for each element in the collection if you use takeIf I would not make this replacement.

[Nir]

I don't think I follow that

[Nir]

collection?

[Tim VanFosson]

filters operate on collections, I'm assuming foo is therefore some type of collection

[xii]

got you, im keeping an if i think

[Kroppeb]

In this case a normal if is prefered

[Arkadii Ivanov]

foo.takeIf { condition }?.filter {} ?: foo

[Nir]

@Tim VanFosson I'm not sure why you say that if the condition isn't true, you're still going to evaluate something still for each element of the collection

[Nir]

All of these things, ?:, ?. should be properly short circuiting

[Tim VanFosson]

nvm, I'm relatively new to Kotlin and I was confusing it with takeWhile