mirror of
https://github.com/golang/go
synced 2024-11-22 19:34:59 -07:00
e24977d231
The next CL will remove the -G flag, effectively hard-coding it to its current default (-G=3). Change-Id: Ib4743b529206928f9f1cca9fdb19989728327831 Reviewed-on: https://go-review.googlesource.com/c/go/+/388534 Reviewed-by: Keith Randall <khr@golang.org> Trust: Matthew Dempsky <mdempsky@google.com> Run-TryBot: Matthew Dempsky <mdempsky@google.com> TryBot-Result: Gopher Robot <gobot@golang.org>
82 lines
1.4 KiB
Go
82 lines
1.4 KiB
Go
// run
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// Copyright 2021 The Go Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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package main
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type Iterator[T any] interface {
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Iterate(fn func(T) bool)
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}
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type IteratorFunc[T any] func(fn func(T) bool)
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func (f IteratorFunc[T]) Iterate(fn func(T) bool) {
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f(fn)
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}
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type Stream[T any] struct {
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it Iterator[T]
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}
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func (s Stream[T]) Iterate(fn func(T) bool) {
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if s.it == nil {
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return
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}
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s.it.Iterate(fn)
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}
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func FromIterator[T any](it Iterator[T]) Stream[T] {
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return Stream[T]{it: it}
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}
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func (s Stream[T]) DropWhile(fn func(T) bool) Stream[T] {
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return Pipe[T, T](s, func(t T) (T, bool) {
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return t, true
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})
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}
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func Pipe[T, R any](s Stream[T], op func(d T) (R, bool)) Stream[R] {
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it := func(fn func(R) bool) {
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// XXX Not getting the closure right when converting to interface.
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// s.it.Iterate(func(t T) bool {
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// r, ok := op(t)
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// if !ok {
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// return true
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// }
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// return fn(r)
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// })
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}
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return FromIterator[R](IteratorFunc[R](it))
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}
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func Reduce[T, U any](s Stream[T], identity U, acc func(U, T) U) (r U) {
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r = identity
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s.Iterate(func(t T) bool {
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r = acc(r, t)
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return true
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})
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return r
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}
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type myIterator struct {
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}
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func (myIterator) Iterate(fn func(int) bool) {
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}
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func main() {
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s := Stream[int]{}
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s.it = myIterator{}
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s = s.DropWhile(func(i int) bool {
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return false
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})
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Reduce(s, nil, func(acc []int, e int) []int {
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return append(acc, e)
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})
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}
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