mirror of
https://github.com/golang/go
synced 2024-11-24 17:30:18 -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
|
|
|
|
// Copyright 2021 The Go Authors. All rights reserved.
|
|
// Use of this source code is governed by a BSD-style
|
|
// license that can be found in the LICENSE file.
|
|
|
|
package main
|
|
|
|
type Iterator[T any] interface {
|
|
Iterate(fn func(T) bool)
|
|
}
|
|
|
|
type IteratorFunc[T any] func(fn func(T) bool)
|
|
|
|
func (f IteratorFunc[T]) Iterate(fn func(T) bool) {
|
|
f(fn)
|
|
}
|
|
|
|
type Stream[T any] struct {
|
|
it Iterator[T]
|
|
}
|
|
|
|
func (s Stream[T]) Iterate(fn func(T) bool) {
|
|
if s.it == nil {
|
|
return
|
|
}
|
|
s.it.Iterate(fn)
|
|
}
|
|
|
|
func FromIterator[T any](it Iterator[T]) Stream[T] {
|
|
return Stream[T]{it: it}
|
|
}
|
|
|
|
func (s Stream[T]) DropWhile(fn func(T) bool) Stream[T] {
|
|
return Pipe[T, T](s, func(t T) (T, bool) {
|
|
return t, true
|
|
})
|
|
}
|
|
|
|
func Pipe[T, R any](s Stream[T], op func(d T) (R, bool)) Stream[R] {
|
|
it := func(fn func(R) bool) {
|
|
// XXX Not getting the closure right when converting to interface.
|
|
// s.it.Iterate(func(t T) bool {
|
|
// r, ok := op(t)
|
|
// if !ok {
|
|
// return true
|
|
// }
|
|
|
|
// return fn(r)
|
|
// })
|
|
}
|
|
|
|
return FromIterator[R](IteratorFunc[R](it))
|
|
}
|
|
|
|
func Reduce[T, U any](s Stream[T], identity U, acc func(U, T) U) (r U) {
|
|
r = identity
|
|
s.Iterate(func(t T) bool {
|
|
r = acc(r, t)
|
|
return true
|
|
})
|
|
|
|
return r
|
|
}
|
|
|
|
type myIterator struct {
|
|
}
|
|
|
|
func (myIterator) Iterate(fn func(int) bool) {
|
|
}
|
|
|
|
func main() {
|
|
s := Stream[int]{}
|
|
s.it = myIterator{}
|
|
s = s.DropWhile(func(i int) bool {
|
|
return false
|
|
})
|
|
Reduce(s, nil, func(acc []int, e int) []int {
|
|
return append(acc, e)
|
|
})
|
|
}
|