Initial commit: Go 1.23 release state

test/typeparam/issue48645b.go

@@ -0,0 +1,81 @@
+// 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)
+	})
+}