mirror of
https://github.com/golang/go
synced 2024-11-24 14:20:13 -07:00
df4c625d88
Add (temporary) syntax.AllowTypeLists mode to control the acceptance of type lists; the compiler doesn't set it, but existing syntax and types2 tests do so that the code remains exercised while it exists. Adjust various tests to use the type set notation. Change-Id: I798e607912552db6bfe38a7cd4324b74c6bf4d95 Reviewed-on: https://go-review.googlesource.com/c/go/+/347249 Trust: Robert Griesemer <gri@golang.org> Run-TryBot: Robert Griesemer <gri@golang.org> TryBot-Result: Go Bot <gobot@golang.org> Reviewed-by: Robert Findley <rfindley@google.com>
73 lines
1.6 KiB
Go
73 lines
1.6 KiB
Go
// run -gcflags=-G=3
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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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import (
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"fmt"
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"reflect"
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)
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type Number interface {
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~int | ~int8 | ~int16 | ~int32 | ~int64 | ~uint | ~uint8 | ~uint16 | ~uint32 | ~uint64 | ~uintptr | ~float32 | ~float64
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}
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type MySlice []int
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type MyFloatSlice []float64
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type _SliceOf[E any] interface {
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~[]E
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}
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func _DoubleElems[S _SliceOf[E], E Number](s S) S {
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r := make(S, len(s))
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for i, v := range s {
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r[i] = v + v
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}
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return r
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}
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// Test use of untyped constant in an expression with a generically-typed parameter
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func _DoubleElems2[S _SliceOf[E], E Number](s S) S {
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r := make(S, len(s))
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for i, v := range s {
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r[i] = v * 2
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}
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return r
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}
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func main() {
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arg := MySlice{1, 2, 3}
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want := MySlice{2, 4, 6}
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got := _DoubleElems[MySlice, int](arg)
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if !reflect.DeepEqual(got, want) {
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panic(fmt.Sprintf("got %s, want %s", got, want))
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}
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// constraint type inference
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got = _DoubleElems[MySlice](arg)
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if !reflect.DeepEqual(got, want) {
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panic(fmt.Sprintf("got %s, want %s", got, want))
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}
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got = _DoubleElems(arg)
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if !reflect.DeepEqual(got, want) {
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panic(fmt.Sprintf("got %s, want %s", got, want))
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}
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farg := MyFloatSlice{1.2, 2.0, 3.5}
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fwant := MyFloatSlice{2.4, 4.0, 7.0}
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fgot := _DoubleElems(farg)
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if !reflect.DeepEqual(fgot, fwant) {
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panic(fmt.Sprintf("got %s, want %s", fgot, fwant))
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}
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fgot = _DoubleElems2(farg)
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if !reflect.DeepEqual(fgot, fwant) {
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panic(fmt.Sprintf("got %s, want %s", fgot, fwant))
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}
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}
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