reflect: add Type.ConvertibleTo, Value.Convert (API CHANGE)
Fixes #4047.
R=iant, r
CC=golang-dev
https://golang.org/cl/6500065
diff --git a/src/pkg/reflect/all_test.go b/src/pkg/reflect/all_test.go
index fe16087..674285d 100644
--- a/src/pkg/reflect/all_test.go
+++ b/src/pkg/reflect/all_test.go
@@ -7,6 +7,7 @@
import (
"bytes"
"encoding/base64"
+ "flag"
"fmt"
"io"
"math/rand"
@@ -1068,6 +1069,8 @@
panic bool
}
+var allselect = flag.Bool("allselect", false, "exhaustive select test")
+
func TestSelect(t *testing.T) {
selectWatch.once.Do(func() { go selectWatcher() })
@@ -1091,6 +1094,9 @@
if testing.Short() && n >= 1000 {
break
}
+ if n >= 100000 && !*allselect {
+ break
+ }
if n%100000 == 0 && testing.Verbose() {
println("TestSelect", n)
}
@@ -2162,6 +2168,447 @@
}
}
+var V = ValueOf
+
+func EmptyInterfaceV(x interface{}) Value {
+ return ValueOf(&x).Elem()
+}
+
+func ReaderV(x io.Reader) Value {
+ return ValueOf(&x).Elem()
+}
+
+func ReadWriterV(x io.ReadWriter) Value {
+ return ValueOf(&x).Elem()
+}
+
+type Empty struct{}
+type MyString string
+type MyBytes []byte
+type MyRunes []int32
+type MyFunc func()
+type MyByte byte
+
+var convertTests = []struct {
+ in Value
+ out Value
+}{
+ // numbers
+ /*
+ Edit .+1,/\*\//-1>cat >/tmp/x.go && go run /tmp/x.go
+
+ package main
+
+ import "fmt"
+
+ var numbers = []string{
+ "int8", "uint8", "int16", "uint16",
+ "int32", "uint32", "int64", "uint64",
+ "int", "uint", "uintptr",
+ "float32", "float64",
+ }
+
+ func main() {
+ // all pairs but in an unusual order,
+ // to emit all the int8, uint8 cases
+ // before n grows too big.
+ n := 1
+ for i, f := range numbers {
+ for _, g := range numbers[i:] {
+ fmt.Printf("\t{V(%s(%d)), V(%s(%d))},\n", f, n, g, n)
+ n++
+ if f != g {
+ fmt.Printf("\t{V(%s(%d)), V(%s(%d))},\n", g, n, f, n)
+ n++
+ }
+ }
+ }
+ }
+ */
+ {V(int8(1)), V(int8(1))},
+ {V(int8(2)), V(uint8(2))},
+ {V(uint8(3)), V(int8(3))},
+ {V(int8(4)), V(int16(4))},
+ {V(int16(5)), V(int8(5))},
+ {V(int8(6)), V(uint16(6))},
+ {V(uint16(7)), V(int8(7))},
+ {V(int8(8)), V(int32(8))},
+ {V(int32(9)), V(int8(9))},
+ {V(int8(10)), V(uint32(10))},
+ {V(uint32(11)), V(int8(11))},
+ {V(int8(12)), V(int64(12))},
+ {V(int64(13)), V(int8(13))},
+ {V(int8(14)), V(uint64(14))},
+ {V(uint64(15)), V(int8(15))},
+ {V(int8(16)), V(int(16))},
+ {V(int(17)), V(int8(17))},
+ {V(int8(18)), V(uint(18))},
+ {V(uint(19)), V(int8(19))},
+ {V(int8(20)), V(uintptr(20))},
+ {V(uintptr(21)), V(int8(21))},
+ {V(int8(22)), V(float32(22))},
+ {V(float32(23)), V(int8(23))},
+ {V(int8(24)), V(float64(24))},
+ {V(float64(25)), V(int8(25))},
+ {V(uint8(26)), V(uint8(26))},
+ {V(uint8(27)), V(int16(27))},
+ {V(int16(28)), V(uint8(28))},
+ {V(uint8(29)), V(uint16(29))},
+ {V(uint16(30)), V(uint8(30))},
+ {V(uint8(31)), V(int32(31))},
+ {V(int32(32)), V(uint8(32))},
+ {V(uint8(33)), V(uint32(33))},
+ {V(uint32(34)), V(uint8(34))},
+ {V(uint8(35)), V(int64(35))},
+ {V(int64(36)), V(uint8(36))},
+ {V(uint8(37)), V(uint64(37))},
+ {V(uint64(38)), V(uint8(38))},
+ {V(uint8(39)), V(int(39))},
+ {V(int(40)), V(uint8(40))},
+ {V(uint8(41)), V(uint(41))},
+ {V(uint(42)), V(uint8(42))},
+ {V(uint8(43)), V(uintptr(43))},
+ {V(uintptr(44)), V(uint8(44))},
+ {V(uint8(45)), V(float32(45))},
+ {V(float32(46)), V(uint8(46))},
+ {V(uint8(47)), V(float64(47))},
+ {V(float64(48)), V(uint8(48))},
+ {V(int16(49)), V(int16(49))},
+ {V(int16(50)), V(uint16(50))},
+ {V(uint16(51)), V(int16(51))},
+ {V(int16(52)), V(int32(52))},
+ {V(int32(53)), V(int16(53))},
+ {V(int16(54)), V(uint32(54))},
+ {V(uint32(55)), V(int16(55))},
+ {V(int16(56)), V(int64(56))},
+ {V(int64(57)), V(int16(57))},
+ {V(int16(58)), V(uint64(58))},
+ {V(uint64(59)), V(int16(59))},
+ {V(int16(60)), V(int(60))},
+ {V(int(61)), V(int16(61))},
+ {V(int16(62)), V(uint(62))},
+ {V(uint(63)), V(int16(63))},
+ {V(int16(64)), V(uintptr(64))},
+ {V(uintptr(65)), V(int16(65))},
+ {V(int16(66)), V(float32(66))},
+ {V(float32(67)), V(int16(67))},
+ {V(int16(68)), V(float64(68))},
+ {V(float64(69)), V(int16(69))},
+ {V(uint16(70)), V(uint16(70))},
+ {V(uint16(71)), V(int32(71))},
+ {V(int32(72)), V(uint16(72))},
+ {V(uint16(73)), V(uint32(73))},
+ {V(uint32(74)), V(uint16(74))},
+ {V(uint16(75)), V(int64(75))},
+ {V(int64(76)), V(uint16(76))},
+ {V(uint16(77)), V(uint64(77))},
+ {V(uint64(78)), V(uint16(78))},
+ {V(uint16(79)), V(int(79))},
+ {V(int(80)), V(uint16(80))},
+ {V(uint16(81)), V(uint(81))},
+ {V(uint(82)), V(uint16(82))},
+ {V(uint16(83)), V(uintptr(83))},
+ {V(uintptr(84)), V(uint16(84))},
+ {V(uint16(85)), V(float32(85))},
+ {V(float32(86)), V(uint16(86))},
+ {V(uint16(87)), V(float64(87))},
+ {V(float64(88)), V(uint16(88))},
+ {V(int32(89)), V(int32(89))},
+ {V(int32(90)), V(uint32(90))},
+ {V(uint32(91)), V(int32(91))},
+ {V(int32(92)), V(int64(92))},
+ {V(int64(93)), V(int32(93))},
+ {V(int32(94)), V(uint64(94))},
+ {V(uint64(95)), V(int32(95))},
+ {V(int32(96)), V(int(96))},
+ {V(int(97)), V(int32(97))},
+ {V(int32(98)), V(uint(98))},
+ {V(uint(99)), V(int32(99))},
+ {V(int32(100)), V(uintptr(100))},
+ {V(uintptr(101)), V(int32(101))},
+ {V(int32(102)), V(float32(102))},
+ {V(float32(103)), V(int32(103))},
+ {V(int32(104)), V(float64(104))},
+ {V(float64(105)), V(int32(105))},
+ {V(uint32(106)), V(uint32(106))},
+ {V(uint32(107)), V(int64(107))},
+ {V(int64(108)), V(uint32(108))},
+ {V(uint32(109)), V(uint64(109))},
+ {V(uint64(110)), V(uint32(110))},
+ {V(uint32(111)), V(int(111))},
+ {V(int(112)), V(uint32(112))},
+ {V(uint32(113)), V(uint(113))},
+ {V(uint(114)), V(uint32(114))},
+ {V(uint32(115)), V(uintptr(115))},
+ {V(uintptr(116)), V(uint32(116))},
+ {V(uint32(117)), V(float32(117))},
+ {V(float32(118)), V(uint32(118))},
+ {V(uint32(119)), V(float64(119))},
+ {V(float64(120)), V(uint32(120))},
+ {V(int64(121)), V(int64(121))},
+ {V(int64(122)), V(uint64(122))},
+ {V(uint64(123)), V(int64(123))},
+ {V(int64(124)), V(int(124))},
+ {V(int(125)), V(int64(125))},
+ {V(int64(126)), V(uint(126))},
+ {V(uint(127)), V(int64(127))},
+ {V(int64(128)), V(uintptr(128))},
+ {V(uintptr(129)), V(int64(129))},
+ {V(int64(130)), V(float32(130))},
+ {V(float32(131)), V(int64(131))},
+ {V(int64(132)), V(float64(132))},
+ {V(float64(133)), V(int64(133))},
+ {V(uint64(134)), V(uint64(134))},
+ {V(uint64(135)), V(int(135))},
+ {V(int(136)), V(uint64(136))},
+ {V(uint64(137)), V(uint(137))},
+ {V(uint(138)), V(uint64(138))},
+ {V(uint64(139)), V(uintptr(139))},
+ {V(uintptr(140)), V(uint64(140))},
+ {V(uint64(141)), V(float32(141))},
+ {V(float32(142)), V(uint64(142))},
+ {V(uint64(143)), V(float64(143))},
+ {V(float64(144)), V(uint64(144))},
+ {V(int(145)), V(int(145))},
+ {V(int(146)), V(uint(146))},
+ {V(uint(147)), V(int(147))},
+ {V(int(148)), V(uintptr(148))},
+ {V(uintptr(149)), V(int(149))},
+ {V(int(150)), V(float32(150))},
+ {V(float32(151)), V(int(151))},
+ {V(int(152)), V(float64(152))},
+ {V(float64(153)), V(int(153))},
+ {V(uint(154)), V(uint(154))},
+ {V(uint(155)), V(uintptr(155))},
+ {V(uintptr(156)), V(uint(156))},
+ {V(uint(157)), V(float32(157))},
+ {V(float32(158)), V(uint(158))},
+ {V(uint(159)), V(float64(159))},
+ {V(float64(160)), V(uint(160))},
+ {V(uintptr(161)), V(uintptr(161))},
+ {V(uintptr(162)), V(float32(162))},
+ {V(float32(163)), V(uintptr(163))},
+ {V(uintptr(164)), V(float64(164))},
+ {V(float64(165)), V(uintptr(165))},
+ {V(float32(166)), V(float32(166))},
+ {V(float32(167)), V(float64(167))},
+ {V(float64(168)), V(float32(168))},
+ {V(float64(169)), V(float64(169))},
+
+ // truncation
+ {V(float64(1.5)), V(int(1))},
+
+ // complex
+ {V(complex64(1i)), V(complex64(1i))},
+ {V(complex64(2i)), V(complex128(2i))},
+ {V(complex128(3i)), V(complex64(3i))},
+ {V(complex128(4i)), V(complex128(4i))},
+
+ // string
+ {V(string("hello")), V(string("hello"))},
+ {V(string("bytes1")), V([]byte("bytes1"))},
+ {V([]byte("bytes2")), V(string("bytes2"))},
+ {V([]byte("bytes3")), V([]byte("bytes3"))},
+ {V(string("runes♝")), V([]rune("runes♝"))},
+ {V([]rune("runes♕")), V(string("runes♕"))},
+ {V([]rune("runes🙈🙉🙊")), V([]rune("runes🙈🙉🙊"))},
+ {V(int('a')), V(string("a"))},
+ {V(int8('a')), V(string("a"))},
+ {V(int16('a')), V(string("a"))},
+ {V(int32('a')), V(string("a"))},
+ {V(int64('a')), V(string("a"))},
+ {V(uint('a')), V(string("a"))},
+ {V(uint8('a')), V(string("a"))},
+ {V(uint16('a')), V(string("a"))},
+ {V(uint32('a')), V(string("a"))},
+ {V(uint64('a')), V(string("a"))},
+ {V(uintptr('a')), V(string("a"))},
+ {V(int(-1)), V(string("\uFFFD"))},
+ {V(int8(-2)), V(string("\uFFFD"))},
+ {V(int16(-3)), V(string("\uFFFD"))},
+ {V(int32(-4)), V(string("\uFFFD"))},
+ {V(int64(-5)), V(string("\uFFFD"))},
+ {V(uint(0x110001)), V(string("\uFFFD"))},
+ {V(uint32(0x110002)), V(string("\uFFFD"))},
+ {V(uint64(0x110003)), V(string("\uFFFD"))},
+ {V(uintptr(0x110004)), V(string("\uFFFD"))},
+
+ // named string
+ {V(MyString("hello")), V(string("hello"))},
+ {V(string("hello")), V(MyString("hello"))},
+ {V(string("hello")), V(string("hello"))},
+ {V(MyString("hello")), V(MyString("hello"))},
+ {V(MyString("bytes1")), V([]byte("bytes1"))},
+ {V([]byte("bytes2")), V(MyString("bytes2"))},
+ {V([]byte("bytes3")), V([]byte("bytes3"))},
+ {V(MyString("runes♝")), V([]rune("runes♝"))},
+ {V([]rune("runes♕")), V(MyString("runes♕"))},
+ {V([]rune("runes🙈🙉🙊")), V([]rune("runes🙈🙉🙊"))},
+ {V([]rune("runes🙈🙉🙊")), V(MyRunes("runes🙈🙉🙊"))},
+ {V(MyRunes("runes🙈🙉🙊")), V([]rune("runes🙈🙉🙊"))},
+ {V(int('a')), V(MyString("a"))},
+ {V(int8('a')), V(MyString("a"))},
+ {V(int16('a')), V(MyString("a"))},
+ {V(int32('a')), V(MyString("a"))},
+ {V(int64('a')), V(MyString("a"))},
+ {V(uint('a')), V(MyString("a"))},
+ {V(uint8('a')), V(MyString("a"))},
+ {V(uint16('a')), V(MyString("a"))},
+ {V(uint32('a')), V(MyString("a"))},
+ {V(uint64('a')), V(MyString("a"))},
+ {V(uintptr('a')), V(MyString("a"))},
+ {V(int(-1)), V(MyString("\uFFFD"))},
+ {V(int8(-2)), V(MyString("\uFFFD"))},
+ {V(int16(-3)), V(MyString("\uFFFD"))},
+ {V(int32(-4)), V(MyString("\uFFFD"))},
+ {V(int64(-5)), V(MyString("\uFFFD"))},
+ {V(uint(0x110001)), V(MyString("\uFFFD"))},
+ {V(uint32(0x110002)), V(MyString("\uFFFD"))},
+ {V(uint64(0x110003)), V(MyString("\uFFFD"))},
+ {V(uintptr(0x110004)), V(MyString("\uFFFD"))},
+
+ // named []byte
+ {V(string("bytes1")), V(MyBytes("bytes1"))},
+ {V(MyBytes("bytes2")), V(string("bytes2"))},
+ {V(MyBytes("bytes3")), V(MyBytes("bytes3"))},
+ {V(MyString("bytes1")), V(MyBytes("bytes1"))},
+ {V(MyBytes("bytes2")), V(MyString("bytes2"))},
+
+ // named []rune
+ {V(string("runes♝")), V(MyRunes("runes♝"))},
+ {V(MyRunes("runes♕")), V(string("runes♕"))},
+ {V(MyRunes("runes🙈🙉🙊")), V(MyRunes("runes🙈🙉🙊"))},
+ {V(MyString("runes♝")), V(MyRunes("runes♝"))},
+ {V(MyRunes("runes♕")), V(MyString("runes♕"))},
+
+ // named types and equal underlying types
+ {V(new(int)), V(new(integer))},
+ {V(new(integer)), V(new(int))},
+ {V(Empty{}), V(struct{}{})},
+ {V(new(Empty)), V(new(struct{}))},
+ {V(struct{}{}), V(Empty{})},
+ {V(new(struct{})), V(new(Empty))},
+ {V(Empty{}), V(Empty{})},
+ {V(MyBytes{}), V([]byte{})},
+ {V([]byte{}), V(MyBytes{})},
+ {V((func())(nil)), V(MyFunc(nil))},
+ {V((MyFunc)(nil)), V((func())(nil))},
+
+ // can convert *byte and *MyByte
+ {V((*byte)(nil)), V((*MyByte)(nil))},
+ {V((*MyByte)(nil)), V((*byte)(nil))},
+
+ // cannot convert mismatched array sizes
+ {V([2]byte{}), V([2]byte{})},
+ {V([3]byte{}), V([3]byte{})},
+
+ // cannot convert other instances
+ {V((**byte)(nil)), V((**byte)(nil))},
+ {V((**MyByte)(nil)), V((**MyByte)(nil))},
+ {V((chan byte)(nil)), V((chan byte)(nil))},
+ {V((chan MyByte)(nil)), V((chan MyByte)(nil))},
+ {V(([]byte)(nil)), V(([]byte)(nil))},
+ {V(([]MyByte)(nil)), V(([]MyByte)(nil))},
+ {V((map[int]byte)(nil)), V((map[int]byte)(nil))},
+ {V((map[int]MyByte)(nil)), V((map[int]MyByte)(nil))},
+ {V((map[byte]int)(nil)), V((map[byte]int)(nil))},
+ {V((map[MyByte]int)(nil)), V((map[MyByte]int)(nil))},
+ {V([2]byte{}), V([2]byte{})},
+ {V([2]MyByte{}), V([2]MyByte{})},
+
+ // other
+ {V((***int)(nil)), V((***int)(nil))},
+ {V((***byte)(nil)), V((***byte)(nil))},
+ {V((***int32)(nil)), V((***int32)(nil))},
+ {V((***int64)(nil)), V((***int64)(nil))},
+ {V((chan int)(nil)), V((<-chan int)(nil))},
+ {V((chan int)(nil)), V((chan<- int)(nil))},
+ {V((chan string)(nil)), V((<-chan string)(nil))},
+ {V((chan string)(nil)), V((chan<- string)(nil))},
+ {V((chan byte)(nil)), V((chan byte)(nil))},
+ {V((chan MyByte)(nil)), V((chan MyByte)(nil))},
+ {V((map[int]bool)(nil)), V((map[int]bool)(nil))},
+ {V((map[int]byte)(nil)), V((map[int]byte)(nil))},
+ {V((map[uint]bool)(nil)), V((map[uint]bool)(nil))},
+ {V([]uint(nil)), V([]uint(nil))},
+ {V([]int(nil)), V([]int(nil))},
+ {V(new(interface{})), V(new(interface{}))},
+ {V(new(io.Reader)), V(new(io.Reader))},
+ {V(new(io.Writer)), V(new(io.Writer))},
+
+ // interfaces
+ {V(int(1)), EmptyInterfaceV(int(1))},
+ {V(string("hello")), EmptyInterfaceV(string("hello"))},
+ {V(new(bytes.Buffer)), ReaderV(new(bytes.Buffer))},
+ {ReadWriterV(new(bytes.Buffer)), ReaderV(new(bytes.Buffer))},
+ {V(new(bytes.Buffer)), ReadWriterV(new(bytes.Buffer))},
+}
+
+func TestConvert(t *testing.T) {
+ canConvert := map[[2]Type]bool{}
+ all := map[Type]bool{}
+
+ for _, tt := range convertTests {
+ t1 := tt.in.Type()
+ if !t1.ConvertibleTo(t1) {
+ t.Errorf("(%s).ConvertibleTo(%s) = false, want true", t1, t1)
+ continue
+ }
+
+ t2 := tt.out.Type()
+ if !t1.ConvertibleTo(t2) {
+ t.Errorf("(%s).ConvertibleTo(%s) = false, want true", t1, t2)
+ continue
+ }
+
+ all[t1] = true
+ all[t2] = true
+ canConvert[[2]Type{t1, t2}] = true
+
+ v1 := tt.in
+ vout1 := v1.Convert(t1)
+ out1 := vout1.Interface()
+ if vout1.Type() != tt.in.Type() || !DeepEqual(out1, tt.in.Interface()) {
+ t.Errorf("ValueOf(%T(%v)).Convert(%s) = %T(%v), want %T(%v)", tt.in.Interface(), tt.in.Interface(), t1, out1, out1, tt.in.Interface(), tt.in.Interface())
+ }
+
+ vout := v1.Convert(t2)
+ out := vout.Interface()
+ if vout.Type() != tt.out.Type() || !DeepEqual(out, tt.out.Interface()) {
+ t.Errorf("ValueOf(%T(%v)).Convert(%s) = %T(%v), want %T(%v)", tt.in.Interface(), tt.in.Interface(), t2, out, out, tt.out.Interface(), tt.out.Interface())
+ }
+
+ if IsRO(v1) {
+ t.Errorf("table entry %v is RO, should not be", v1)
+ }
+ if IsRO(vout1) {
+ t.Errorf("self-conversion output %v is RO, should not be", vout1)
+ }
+ if IsRO(vout) {
+ t.Errorf("conversion output %v is RO, should not be", vout)
+ }
+ if !IsRO(MakeRO(v1).Convert(t1)) {
+ t.Errorf("RO self-conversion output %v is not RO, should be", v1)
+ }
+ if !IsRO(MakeRO(v1).Convert(t2)) {
+ t.Errorf("RO conversion output %v is not RO, should be", v1)
+ }
+ }
+
+ // Assume that of all the types we saw during the tests,
+ // if there wasn't an explicit entry for a conversion between
+ // a pair of types, then it's not to be allowed. This checks for
+ // things like 'int64' converting to '*int'.
+ for t1 := range all {
+ for t2 := range all {
+ expectOK := t1 == t2 || canConvert[[2]Type{t1, t2}] || t2.Kind() == Interface && t2.NumMethod() == 0
+ if ok := t1.ConvertibleTo(t2); ok != expectOK {
+ t.Errorf("(%s).ConvertibleTo(%s) = %v, want %v", t1, t2, ok, expectOK)
+ }
+ }
+ }
+}
+
type B1 struct {
X int
Y int
diff --git a/src/pkg/reflect/export_test.go b/src/pkg/reflect/export_test.go
new file mode 100644
index 0000000..6e0d8a3
--- /dev/null
+++ b/src/pkg/reflect/export_test.go
@@ -0,0 +1,16 @@
+// Copyright 2012 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 reflect
+
+// MakeRO returns a copy of v with the read-only flag set.
+func MakeRO(v Value) Value {
+ v.flag |= flagRO
+ return v
+}
+
+// IsRO reports whether v's read-only flag is set.
+func IsRO(v Value) bool {
+ return v.flag&flagRO != 0
+}
diff --git a/src/pkg/reflect/type.go b/src/pkg/reflect/type.go
index dfbd859..4878f2d 100644
--- a/src/pkg/reflect/type.go
+++ b/src/pkg/reflect/type.go
@@ -92,6 +92,9 @@
// AssignableTo returns true if a value of the type is assignable to type u.
AssignableTo(u Type) bool
+ // ConvertibleTo returns true if a value of the type is convertible to type u.
+ ConvertibleTo(u Type) bool
+
// Methods applicable only to some types, depending on Kind.
// The methods allowed for each kind are:
//
@@ -1096,6 +1099,14 @@
return directlyAssignable(uu, t) || implements(uu, t)
}
+func (t *commonType) ConvertibleTo(u Type) bool {
+ if u == nil {
+ panic("reflect: nil type passed to Type.AssignableTo")
+ }
+ uu := u.(*commonType)
+ return convertOp(uu, t) != nil
+}
+
// implements returns true if the type V implements the interface type T.
func implements(T, V *commonType) bool {
if T.Kind() != Interface {
@@ -1167,10 +1178,28 @@
return false
}
- // x's type T and V have identical underlying types.
- // Since at least one is unnamed, only the composite types
- // need to be considered.
- switch T.Kind() {
+ // x's type T and V must have identical underlying types.
+ return haveIdenticalUnderlyingType(T, V)
+}
+
+func haveIdenticalUnderlyingType(T, V *commonType) bool {
+ if T == V {
+ return true
+ }
+
+ kind := T.Kind()
+ if kind != V.Kind() {
+ return false
+ }
+
+ // Non-composite types of equal kind have same underlying type
+ // (the predefined instance of the type).
+ if Bool <= kind && kind <= Complex128 || kind == String || kind == UnsafePointer {
+ return true
+ }
+
+ // Composite types.
+ switch kind {
case Array:
return T.Elem() == V.Elem() && T.Len() == V.Len()
diff --git a/src/pkg/reflect/value.go b/src/pkg/reflect/value.go
index 1c3dc9a..4d5e386 100644
--- a/src/pkg/reflect/value.go
+++ b/src/pkg/reflect/value.go
@@ -302,6 +302,17 @@
return *(*[]byte)(v.val)
}
+// runes returns v's underlying value.
+// It panics if v's underlying value is not a slice of runes (int32s).
+func (v Value) runes() []rune {
+ v.mustBe(Slice)
+ if v.typ.Elem().Kind() != Int32 {
+ panic("reflect.Value.Bytes of non-rune slice")
+ }
+ // Slice is always bigger than a word; assume flagIndir.
+ return *(*[]rune)(v.val)
+}
+
// CanAddr returns true if the value's address can be obtained with Addr.
// Such values are called addressable. A value is addressable if it is
// an element of a slice, an element of an addressable array,
@@ -1221,6 +1232,17 @@
*(*[]byte)(v.val) = x
}
+// setRunes sets v's underlying value.
+// It panics if v's underlying value is not a slice of runes (int32s).
+func (v Value) setRunes(x []rune) {
+ v.mustBeAssignable()
+ v.mustBe(Slice)
+ if v.typ.Elem().Kind() != Int32 {
+ panic("reflect.Value.setRunes of non-rune slice")
+ }
+ *(*[]rune)(v.val) = x
+}
+
// SetComplex sets v's underlying value to x.
// It panics if v's Kind is not Complex64 or Complex128, or if CanSet() is false.
func (v Value) SetComplex(x complex128) {
@@ -1916,6 +1938,302 @@
panic(context + ": value of type " + v.typ.String() + " is not assignable to type " + dst.String())
}
+// Convert returns the value v converted to type t.
+// If the usual Go conversion rules do not allow conversion
+// of the value v to type t, Convert panics.
+func (v Value) Convert(t Type) Value {
+ if v.flag&flagMethod != 0 {
+ panic("reflect.Value.Convert: cannot convert method values")
+ }
+ op := convertOp(t.common(), v.typ)
+ if op == nil {
+ panic("reflect.Value.Convert: value of type " + v.typ.String() + " cannot be converted to type " + t.String())
+ }
+ return op(v, t)
+}
+
+// convertOp returns the function to convert a value of type src
+// to a value of type dst. If the conversion is illegal, convertOp returns nil.
+func convertOp(dst, src *commonType) func(Value, Type) Value {
+ switch src.Kind() {
+ case Int, Int8, Int16, Int32, Int64:
+ switch dst.Kind() {
+ case Int, Int8, Int16, Int32, Int64, Uint, Uint8, Uint16, Uint32, Uint64, Uintptr:
+ return cvtInt
+ case Float32, Float64:
+ return cvtIntFloat
+ case String:
+ return cvtIntString
+ }
+
+ case Uint, Uint8, Uint16, Uint32, Uint64, Uintptr:
+ switch dst.Kind() {
+ case Int, Int8, Int16, Int32, Int64, Uint, Uint8, Uint16, Uint32, Uint64, Uintptr:
+ return cvtUint
+ case Float32, Float64:
+ return cvtUintFloat
+ case String:
+ return cvtUintString
+ }
+
+ case Float32, Float64:
+ switch dst.Kind() {
+ case Int, Int8, Int16, Int32, Int64:
+ return cvtFloatInt
+ case Uint, Uint8, Uint16, Uint32, Uint64, Uintptr:
+ return cvtFloatUint
+ case Float32, Float64:
+ return cvtFloat
+ }
+
+ case Complex64, Complex128:
+ switch dst.Kind() {
+ case Complex64, Complex128:
+ return cvtComplex
+ }
+
+ case String:
+ if dst.Kind() == Slice && dst.Elem().PkgPath() == "" {
+ switch dst.Elem().Kind() {
+ case Uint8:
+ return cvtStringBytes
+ case Int32:
+ return cvtStringRunes
+ }
+ }
+
+ case Slice:
+ if dst.Kind() == String && src.Elem().PkgPath() == "" {
+ switch src.Elem().Kind() {
+ case Uint8:
+ return cvtBytesString
+ case Int32:
+ return cvtRunesString
+ }
+ }
+ }
+
+ // dst and src have same underlying type.
+ if haveIdenticalUnderlyingType(dst, src) {
+ return cvtDirect
+ }
+
+ // dst and src are unnamed pointer types with same underlying base type.
+ if dst.Kind() == Ptr && dst.Name() == "" &&
+ src.Kind() == Ptr && src.Name() == "" &&
+ haveIdenticalUnderlyingType(dst.Elem().common(), src.Elem().common()) {
+ return cvtDirect
+ }
+
+ if implements(dst, src) {
+ if src.Kind() == Interface {
+ return cvtI2I
+ }
+ return cvtT2I
+ }
+
+ return nil
+}
+
+// makeInt returns a Value of type t equal to bits (possibly truncated),
+// where t is a signed or unsigned int type.
+func makeInt(f flag, bits uint64, t Type) Value {
+ typ := t.common()
+ if typ.size > ptrSize {
+ // Assume ptrSize >= 4, so this must be uint64.
+ ptr := unsafe_New(t)
+ *(*uint64)(unsafe.Pointer(ptr)) = bits
+ return Value{typ, ptr, f | flag(typ.Kind())<<flagKindShift}
+ }
+ var w iword
+ switch typ.size {
+ case 1:
+ *(*uint8)(unsafe.Pointer(&w)) = uint8(bits)
+ case 2:
+ *(*uint16)(unsafe.Pointer(&w)) = uint16(bits)
+ case 4:
+ *(*uint32)(unsafe.Pointer(&w)) = uint32(bits)
+ case 8:
+ *(*uint64)(unsafe.Pointer(&w)) = uint64(bits)
+ }
+ return Value{typ, unsafe.Pointer(w), f | flag(typ.Kind())<<flagKindShift}
+}
+
+// makeFloat returns a Value of type t equal to v (possibly truncated to float32),
+// where t is a float32 or float64 type.
+func makeFloat(f flag, v float64, t Type) Value {
+ typ := t.common()
+ if typ.size > ptrSize {
+ // Assume ptrSize >= 4, so this must be float64.
+ ptr := unsafe_New(t)
+ *(*float64)(unsafe.Pointer(ptr)) = v
+ return Value{typ, ptr, f | flag(typ.Kind())<<flagKindShift}
+ }
+
+ var w iword
+ switch typ.size {
+ case 4:
+ *(*float32)(unsafe.Pointer(&w)) = float32(v)
+ case 8:
+ *(*float64)(unsafe.Pointer(&w)) = v
+ }
+ return Value{typ, unsafe.Pointer(w), f | flag(typ.Kind())<<flagKindShift}
+}
+
+// makeComplex returns a Value of type t equal to v (possibly truncated to complex64),
+// where t is a complex64 or complex128 type.
+func makeComplex(f flag, v complex128, t Type) Value {
+ typ := t.common()
+ if typ.size > ptrSize {
+ ptr := unsafe_New(t)
+ switch typ.size {
+ case 8:
+ *(*complex64)(unsafe.Pointer(ptr)) = complex64(v)
+ case 16:
+ *(*complex128)(unsafe.Pointer(ptr)) = v
+ }
+ return Value{typ, ptr, f | flag(typ.Kind())<<flagKindShift}
+ }
+
+ // Assume ptrSize <= 8 so this must be complex64.
+ var w iword
+ *(*complex64)(unsafe.Pointer(&w)) = complex64(v)
+ return Value{typ, unsafe.Pointer(w), f | flag(typ.Kind())<<flagKindShift}
+}
+
+func makeString(f flag, v string, t Type) Value {
+ ret := New(t).Elem()
+ ret.SetString(v)
+ ret.flag = ret.flag&^flagAddr | f
+ return ret
+}
+
+func makeBytes(f flag, v []byte, t Type) Value {
+ ret := New(t).Elem()
+ ret.SetBytes(v)
+ ret.flag = ret.flag&^flagAddr | f
+ return ret
+}
+
+func makeRunes(f flag, v []rune, t Type) Value {
+ ret := New(t).Elem()
+ ret.setRunes(v)
+ ret.flag = ret.flag&^flagAddr | f
+ return ret
+}
+
+// These conversion functions are returned by convertOp
+// for classes of conversions. For example, the first function, cvtInt,
+// takes any value v of signed int type and returns the value converted
+// to type t, where t is any signed or unsigned int type.
+
+// convertOp: intXX -> [u]intXX
+func cvtInt(v Value, t Type) Value {
+ return makeInt(v.flag&flagRO, uint64(v.Int()), t)
+}
+
+// convertOp: uintXX -> [u]intXX
+func cvtUint(v Value, t Type) Value {
+ return makeInt(v.flag&flagRO, v.Uint(), t)
+}
+
+// convertOp: floatXX -> intXX
+func cvtFloatInt(v Value, t Type) Value {
+ return makeInt(v.flag&flagRO, uint64(int64(v.Float())), t)
+}
+
+// convertOp: floatXX -> uintXX
+func cvtFloatUint(v Value, t Type) Value {
+ return makeInt(v.flag&flagRO, uint64(v.Float()), t)
+}
+
+// convertOp: intXX -> floatXX
+func cvtIntFloat(v Value, t Type) Value {
+ return makeFloat(v.flag&flagRO, float64(v.Int()), t)
+}
+
+// convertOp: uintXX -> floatXX
+func cvtUintFloat(v Value, t Type) Value {
+ return makeFloat(v.flag&flagRO, float64(v.Uint()), t)
+}
+
+// convertOp: floatXX -> floatXX
+func cvtFloat(v Value, t Type) Value {
+ return makeFloat(v.flag&flagRO, v.Float(), t)
+}
+
+// convertOp: complexXX -> complexXX
+func cvtComplex(v Value, t Type) Value {
+ return makeComplex(v.flag&flagRO, v.Complex(), t)
+}
+
+// convertOp: intXX -> string
+func cvtIntString(v Value, t Type) Value {
+ return makeString(v.flag&flagRO, string(v.Int()), t)
+}
+
+// convertOp: uintXX -> string
+func cvtUintString(v Value, t Type) Value {
+ return makeString(v.flag&flagRO, string(v.Uint()), t)
+}
+
+// convertOp: []byte -> string
+func cvtBytesString(v Value, t Type) Value {
+ return makeString(v.flag&flagRO, string(v.Bytes()), t)
+}
+
+// convertOp: string -> []byte
+func cvtStringBytes(v Value, t Type) Value {
+ return makeBytes(v.flag&flagRO, []byte(v.String()), t)
+}
+
+// convertOp: []rune -> string
+func cvtRunesString(v Value, t Type) Value {
+ return makeString(v.flag&flagRO, string(v.runes()), t)
+}
+
+// convertOp: string -> []rune
+func cvtStringRunes(v Value, t Type) Value {
+ return makeRunes(v.flag&flagRO, []rune(v.String()), t)
+}
+
+// convertOp: direct copy
+func cvtDirect(v Value, typ Type) Value {
+ f := v.flag
+ t := typ.common()
+ val := v.val
+ if f&flagAddr != 0 {
+ // indirect, mutable word - make a copy
+ ptr := unsafe_New(t)
+ memmove(ptr, val, t.size)
+ val = ptr
+ f &^= flagAddr
+ }
+ return Value{t, val, v.flag&flagRO | f}
+}
+
+// convertOp: concrete -> interface
+func cvtT2I(v Value, typ Type) Value {
+ target := new(interface{})
+ x := valueInterface(v, false)
+ if typ.NumMethod() == 0 {
+ *target = x
+ } else {
+ ifaceE2I(typ.runtimeType(), x, unsafe.Pointer(target))
+ }
+ return Value{typ.common(), unsafe.Pointer(target), v.flag&flagRO | flagIndir | flag(Interface)<<flagKindShift}
+}
+
+// convertOp: interface -> interface
+func cvtI2I(v Value, typ Type) Value {
+ if v.IsNil() {
+ ret := Zero(typ)
+ ret.flag |= v.flag & flagRO
+ return ret
+ }
+ return cvtT2I(v.Elem(), typ)
+}
+
// implemented in ../pkg/runtime
func chancap(ch iword) int32
func chanclose(ch iword)
