Andrey Breslav
27 lines
471 B
Plaintext
27 lines
471 B
Plaintext
open class Builder<E, R> {
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[operator] fun plusAssign(item : E)
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fun result() : R
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}
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open class Buildable {
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fun newBuilder<E, R>() : Builder<E, R>
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}
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class List<T> {
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class object : Buildable {
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override fun newBuilder<E, R>() : Builder<E, R>
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}
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}
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fun <E, T, R> Map<E, T>.map(f : (E) -> R) : T<R> where
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T : Iterable<E>,
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class object T : Buildable<E, T> = {
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val builder = T.newBuilder()
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for (e in this) {
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builder += f(e)
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}
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builder.result()
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} |