Add an encodeCollection extension #1749
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| public inline fun Encoder.encodeCollection( | ||
| descriptor: SerialDescriptor, | ||
| collectionSize: Int, | ||
| block: CompositeEncoder.() -> Unit | ||
| ) { | ||
| val composite = beginCollection(descriptor, collectionSize) | ||
| var ex: Throwable? = null | ||
| try { | ||
| composite.block() | ||
| } catch (e: Throwable) { | ||
| ex = e | ||
| throw e | ||
| } finally { | ||
| // End structure only if there is no exception, otherwise it can be swallowed | ||
| if (ex == null) composite.endStructure(descriptor) | ||
| } | ||
| } |
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Given the way that collections work, it would make sense to put the element iteration in the helper, not just the structure part. Why not use something like:
fun encodeCollection(
descriptor: SerialDescriptor,
collection: Collection<T>,
encodeElement: CompositeEncoder.(T) -> Unit
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You can encode things using a collection structure that aren't collections themselves. The simplest example are arrays.
I don't understand the first part, are you talking about which file the extension lives in or something else?
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@ansman The first part refers to the idea that you would possibly want encodeCollection to actually enforce/provide the expected semantics of a collection rather than leaving this to the caller. As to arrays, you can always overload the helper for array types.
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I like that idea but I don't want to reduce the flexibility of not enforcing a collection. Instead two extensions could be added (one that accepts a collection size and one that accepts a collection).
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Thanks for taking care of it!
Could you please also make the new signatures right?
It's our mistake that we haven't marked the original signatures as crossinline, so the ugly workaround with catch is necessary. We aim to break it (on the source level) in 1.4.0, but these can be done in the desired way from the very beginning.
With crossinline, it can be as straightforward as start() block() end() without catch and finally blocks
|
Sure can! |
This is akin to encodeStructure but for collections. This fixes Kotlin#1748
ansman
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This is akin to encodeStructure but for collections.
This fixes #1748