Your IP : 172.28.240.42
// 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.
// Test situations where functions/methods are not
// immediately called and we need to capture the dictionary
// required for later invocation.
package main
import (
"fmt"
)
func main() {
functions()
methodExpressions()
genMethodExpressions[int](7)
methodValues()
genMethodValues[int](7)
interfaceMethods()
globals()
recursive()
}
func g0[T any](x T) {
}
func g1[T any](x T) T {
return x
}
func g2[T any](x T) (T, T) {
return x, x
}
func functions() {
f0 := g0[int]
f0(7)
f1 := g1[int]
is7(f1(7))
f2 := g2[int]
is77(f2(7))
}
func is7(x int) {
if x != 7 {
println(x)
panic("assertion failed")
}
}
func is77(x, y int) {
if x != 7 || y != 7 {
println(x, y)
panic("assertion failed")
}
}
type s[T any] struct {
a T
}
func (x s[T]) g0() {
}
func (x s[T]) g1() T {
return x.a
}
func (x s[T]) g2() (T, T) {
return x.a, x.a
}
func methodExpressions() {
x := s[int]{a: 7}
f0 := s[int].g0
f0(x)
f0p := (*s[int]).g0
f0p(&x)
f1 := s[int].g1
is7(f1(x))
f1p := (*s[int]).g1
is7(f1p(&x))
f2 := s[int].g2
is77(f2(x))
f2p := (*s[int]).g2
is77(f2p(&x))
}
func genMethodExpressions[T comparable](want T) {
x := s[T]{a: want}
f0 := s[T].g0
f0(x)
f0p := (*s[T]).g0
f0p(&x)
f1 := s[T].g1
if got := f1(x); got != want {
panic(fmt.Sprintf("f1(x) == %d, want %d", got, want))
}
f1p := (*s[T]).g1
if got := f1p(&x); got != want {
panic(fmt.Sprintf("f1p(&x) == %d, want %d", got, want))
}
f2 := s[T].g2
if got1, got2 := f2(x); got1 != want || got2 != want {
panic(fmt.Sprintf("f2(x) == %d, %d, want %d, %d", got1, got2, want, want))
}
}
func methodValues() {
x := s[int]{a: 7}
f0 := x.g0
f0()
f1 := x.g1
is7(f1())
f2 := x.g2
is77(f2())
}
func genMethodValues[T comparable](want T) {
x := s[T]{a: want}
f0 := x.g0
f0()
f1 := x.g1
if got := f1(); got != want {
panic(fmt.Sprintf("f1() == %d, want %d", got, want))
}
f2 := x.g2
if got1, got2 := f2(); got1 != want || got2 != want {
panic(fmt.Sprintf("f2() == %d, %d, want %d, %d", got1, got2, want, want))
}
}
var x interface {
g0()
g1() int
g2() (int, int)
} = s[int]{a: 7}
var y interface{} = s[int]{a: 7}
func interfaceMethods() {
x.g0()
is7(x.g1())
is77(x.g2())
y.(interface{ g0() }).g0()
is7(y.(interface{ g1() int }).g1())
is77(y.(interface{ g2() (int, int) }).g2())
}
// Also check for instantiations outside functions.
var gg0 = g0[int]
var gg1 = g1[int]
var gg2 = g2[int]
var hh0 = s[int].g0
var hh1 = s[int].g1
var hh2 = s[int].g2
var xtop = s[int]{a: 7}
var ii0 = x.g0
var ii1 = x.g1
var ii2 = x.g2
func globals() {
gg0(7)
is7(gg1(7))
is77(gg2(7))
x := s[int]{a: 7}
hh0(x)
is7(hh1(x))
is77(hh2(x))
ii0()
is7(ii1())
is77(ii2())
}
func recursive() {
if got, want := recur1[int](5), 110; got != want {
panic(fmt.Sprintf("recur1[int](5) = %d, want = %d", got, want))
}
}
type Integer interface {
int | int32 | int64
}
func recur1[T Integer](n T) T {
if n == 0 || n == 1 {
return T(1)
} else {
return n * recur2(n-1)
}
}
func recur2[T Integer](n T) T {
list := make([]T, n)
for i, _ := range list {
list[i] = T(i + 1)
}
var sum T
for _, elt := range list {
sum += elt
}
return sum + recur1(n-1)
}