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Introduce new overloads of flatMap and flatMapTo

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- Sequence<T>.flatMap((T) -> Iterable<R>)
- Iterable<T>.flatMap((T) -> Sequence<R>)
- Array<T>.flatMap((T) -> Sequence<R>)
- Map.flatMap((Entry) -> Sequence<R>)

KT-34506
This commit is contained in:
Ilya Gorbunov
2020-04-24 05:15:07 +03:00
parent 562788ceb9
commit bdd53ee9cd
10 changed files with 233 additions and 9 deletions
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libraries/tools/kotlin-stdlib-gen/src/templates/Mapping.kt
+60 -2
View File
@@ -304,7 +304,37 @@ object Mapping : TemplateGroupBase() {
}
specialFor(Sequences) {
inline(Inline.No)
signature("flatMap(transform: (T) -> Sequence<R>)")
since("1.4")
annotation("@OptIn(kotlin.experimental.ExperimentalTypeInference::class)")
annotation("@OverloadResolutionByLambdaReturnType")
annotation("""@kotlin.jvm.JvmName("flatMapIterable")""")
doc { "Returns a single sequence of all elements from results of [transform] function being invoked on each element of original sequence." }
returns("Sequence<R>")
body {
"return FlatteningSequence(this, transform, { it.iterator() })"
}
}
}
val f_flatMapSequence = fn("flatMap(transform: (T) -> Sequence<R>)") {
include(Sequences, Iterables, ArraysOfObjects, Maps)
} builder {
inline()
doc { "Returns a single list of all elements yielded from results of [transform] function being invoked on each ${f.element} of original ${f.collection}." }
sample("samples.collections.Collections.Transformations.flatMap")
typeParam("R")
returns("List<R>")
body {
"return flatMapTo(ArrayList<R>(), transform)"
}
if (f != Sequences) {
since("1.4")
annotation("@OptIn(kotlin.experimental.ExperimentalTypeInference::class)")
annotation("@OverloadResolutionByLambdaReturnType")
annotation("""@kotlin.jvm.JvmName("flatMapSequence")""")
}
specialFor(Sequences) {
inline(Inline.No)
doc { "Returns a single sequence of all elements from results of [transform] function being invoked on each element of original sequence." }
returns("Sequence<R>")
body {
@@ -322,7 +352,35 @@ object Mapping : TemplateGroupBase() {
doc { "Appends all elements yielded from results of [transform] function being invoked on each ${f.element} of original ${f.collection}, to the given [destination]." }
specialFor(Sequences) {
signature("flatMapTo(destination: C, transform: (T) -> Sequence<R>)")
since("1.4")
annotation("@OptIn(kotlin.experimental.ExperimentalTypeInference::class)")
annotation("@OverloadResolutionByLambdaReturnType")
annotation("""@kotlin.jvm.JvmName("flatMapIterableTo")""")
}
typeParam("R")
typeParam("C : MutableCollection<in R>")
returns("C")
body {
"""
for (element in this) {
val list = transform(element)
destination.addAll(list)
}
return destination
"""
}
}
val f_flatMapToSequence = fn("flatMapTo(destination: C, transform: (T) -> Sequence<R>)") {
include(Sequences, Iterables, ArraysOfObjects, Maps)
} builder {
inline()
doc { "Appends all elements yielded from results of [transform] function being invoked on each ${f.element} of original ${f.collection}, to the given [destination]." }
if (f != Sequences) {
since("1.4")
annotation("@OptIn(kotlin.experimental.ExperimentalTypeInference::class)")
annotation("@OverloadResolutionByLambdaReturnType")
annotation("""@kotlin.jvm.JvmName("flatMapSequenceTo")""")
}
typeParam("R")
typeParam("C : MutableCollection<in R>")