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mirror of https://github.com/golang/go synced 2024-11-17 17:14:45 -07:00
go/test/typeparam/stringer.go
Dan Scales c0aa7bd760 [dev.typeparams] cmd/compile: small fixes for stenciling
- Create the stencil name using targ.Type.String(), which handles cases
   where, for example, a type argument is a pointer to a named type,
   etc. *obj.

 - Set name.Def properly for a new stenciled func (have the symbol point
   back to the associated function node).  Will be required when exporting.

 - Add missing copying of Func field when making copies of Name nodes.
   (On purpose (it seems), Name nodes don't have a copy() function, so
   we have to copy all the needed fields explicitly.)

 - Deal with nil type in subster.node(), which is the type of the return
   value for a function that doesn't return anything.

 - Fix min to match standard want/go form, and add in float tests.  Changed
   Got -> got in bunch of other typeparam tests.

 - Add new tests index.go, settable.go, and smallest.go (similar to
   examples in the type param proposal), some of which need the above
   changes.

Change-Id: I09a72302bc1fd3635a326da92405222afa222e85
Reviewed-on: https://go-review.googlesource.com/c/go/+/291109
Trust: Dan Scales <danscales@google.com>
Trust: Robert Griesemer <gri@golang.org>
Run-TryBot: Dan Scales <danscales@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>
2021-02-11 21:46:39 +00:00

89 lines
1.6 KiB
Go

// run -gcflags=-G=3
// 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.
// Test method calls on type parameters
package main
import (
"fmt"
"reflect"
"strconv"
)
// Simple constraint
type Stringer interface {
String() string
}
func stringify[T Stringer](s []T) (ret []string) {
for _, v := range s {
ret = append(ret, v.String())
}
return ret
}
type myint int
func (i myint) String() string {
return strconv.Itoa(int(i))
}
// Constraint with an embedded interface, but still only requires String()
type Stringer2 interface {
CanBeStringer2() int
SubStringer2
}
type SubStringer2 interface {
CanBeSubStringer2() int
String() string
}
func stringify2[T Stringer2](s []T) (ret []string) {
for _, v := range s {
ret = append(ret, v.String())
}
return ret
}
func (myint) CanBeStringer2() int {
return 0
}
func (myint) CanBeSubStringer2() int {
return 0
}
// Test use of method values that are not called
func stringify3[T Stringer](s []T) (ret []string) {
for _, v := range s {
f := v.String
ret = append(ret, f())
}
return ret
}
func main() {
x := []myint{myint(1), myint(2), myint(3)}
got := stringify(x)
want := []string{"1", "2", "3"}
if !reflect.DeepEqual(got, want) {
panic(fmt.Sprintf("got %s, want %s", got, want))
}
got = stringify2(x)
if !reflect.DeepEqual(got, want) {
panic(fmt.Sprintf("got %s, want %s", got, want))
}
got = stringify3(x)
if !reflect.DeepEqual(got, want) {
panic(fmt.Sprintf("got %s, want %s", got, want))
}
}