I notice Compose for Web API uses `inline` quite a bit more

Question

I notice Compose for Web API uses `inline` quite a bit more than I d expect Is that to reduce the final javascript bundle size

David Herman · Answer

This file has a bunch of examples <https github com JetBrains compose jb blob 2536c297668b6d309507433236849c3b299eefce web core src jsMain kotlin org jetbrains compose web css CSSEnums kt L6|https github com JetBrains compose jb blob 2536c297668b6d309507433236849c3b299ee ore src jsMain kotlin org jetbrains compose web css CSSEnums kt>

David Herman · Answer

Here are some more <https github com JetBrains compose jb blob 83870dde5dfc84b82347d0c145920b0dd58bbc25 web core src jsMain kotlin org jetbrains compose web css Color kt L33|https github com JetBrains compose jb blob 83870dde5dfc84b82347d0c145920b0dd58bb b core src jsMain kotlin org jetbrains compose web css Color kt>

David Herman · Answer

If this is to reduce the final binary size then 1 If I m writing a Compose for Web library should I try to follow this pattern 2 Is this a temporary limitation Is tree shaking going to come for Kotlin JS sooner or later

Big Chungus · Answer

If anything inline bloats the bundle size Main benefits of inline functions are runtime performance

Big Chungus · Answer

es6 support is on the roadmap but suspended until IR backend is stable

David Herman · Answer

Are these premature optimizations then I can t imagine setting css style properties are something that is happening in a tight loop or in large volume Maybe concerns about startup time

Big Chungus · Answer

HOWEVER using inline with unsafeCast saves bundle size as end result is pretty much 0 as opposed to creating an entire new function just to change compile time type

David Herman · Answer

Ah ok so sometimes it does gotcha

Big Chungus · Answer

Kotlin js has quite a few special functions in stdlib that are not real functions but rather hints for the compiler

David Herman · Answer

Ok thanks I see

David Herman · Answer

I think in the cases I linked to above both ultimately delegate to unsafe cast so it s probably that happening here

David Herman · Answer

Thanks for the info

Big Chungus · Answer

I m sure JB guys didn t just do things randomly grinning

David Herman · Answer

Me too but I didn t understand why and wasn t sure if or when I should be imitating it