TheArchive/tailscale
1
0
Fork 0
mirror of https://github.com/tailscale/tailscale.git synced 2025-08-12 13:48:01 +00:00
Code Issues Packages Projects Releases Wiki Activity

cmd/cloner, cmd/viewer, util/codegen: add support for generic types and interfaces

Browse Source 
This adds support for generic types and interfaces to our cloner and viewer codegens.
It updates these packages to determine whether to make shallow or deep copies based
on the type parameter constraints. Additionally, if a template parameter or an interface
type has View() and Clone() methods, we'll use them for getters and the cloner of the
owning structure.

Updates #12736

Signed-off-by: Nick Khyl <nickk@tailscale.com>
This commit is contained in:
Nick Khyl
2024-07-08 10:11:00 -05:00
committed by Nick Khyl
parent b7c3cfe049
commit fc28c8e7f3
9 changed files with 1039 additions and 114 deletions
Download Patch File Download Diff File Expand all files Collapse all files

87
cmd/cloner/cloner.go
View File

@@ -91,16 +91,19 @@ func gen(buf *bytes.Buffer, it *codegen.ImportTracker, typ *types.Named) {
}
name := typ.Obj().Name()
typeParams := typ.Origin().TypeParams()
_, typeParamNames := codegen.FormatTypeParams(typeParams, it)
nameWithParams := name + typeParamNames
fmt.Fprintf(buf, "// Clone makes a deep copy of %s.\n", name)
fmt.Fprintf(buf, "// The result aliases no memory with the original.\n")
fmt.Fprintf(buf, "func (src *%s) Clone() *%s {\n", name, name)
fmt.Fprintf(buf, "func (src *%s) Clone() *%s {\n", nameWithParams, nameWithParams)
writef := func(format string, args ...any) {
fmt.Fprintf(buf, "\t"+format+"\n", args...)
}
writef("if src == nil {")
writef("\treturn nil")
writef("}")
writef("dst := new(%s)", name)
writef("dst := new(%s)", nameWithParams)
writef("*dst = *src")
for i := range t.NumFields() {
fname := t.Field(i).Name()
@@ -126,16 +129,23 @@ func gen(buf *bytes.Buffer, it *codegen.ImportTracker, typ *types.Named) {
writef("dst.%s = make([]%s, len(src.%s))", fname, n, fname)
writef("for i := range dst.%s {", fname)
if ptr, isPtr := ft.Elem().(*types.Pointer); isPtr {
if _, isBasic := ptr.Elem().Underlying().(*types.Basic); isBasic {
it.Import("tailscale.com/types/ptr")
writef("if src.%s[i] == nil { dst.%s[i] = nil } else {", fname, fname)
writef("\tdst.%s[i] = ptr.To(*src.%s[i])", fname, fname)
writef("}")
writef("if src.%s[i] == nil { dst.%s[i] = nil } else {", fname, fname)
if codegen.ContainsPointers(ptr.Elem()) {
if _, isIface := ptr.Elem().Underlying().(*types.Interface); isIface {
it.Import("tailscale.com/types/ptr")
writef("\tdst.%s[i] = ptr.To((*src.%s[i]).Clone())", fname, fname)
} else {
writef("\tdst.%s[i] = src.%s[i].Clone()", fname, fname)
}
} else {
writef("\tdst.%s[i] = src.%s[i].Clone()", fname, fname)
it.Import("tailscale.com/types/ptr")
writef("\tdst.%s[i] = ptr.To(*src.%s[i])", fname, fname)
}
writef("}")
} else if ft.Elem().String() == "encoding/json.RawMessage" {
writef("\tdst.%s[i] = append(src.%s[i][:0:0], src.%s[i]...)", fname, fname, fname)
} else if _, isIface := ft.Elem().Underlying().(*types.Interface); isIface {
writef("\tdst.%s[i] = src.%s[i].Clone()", fname, fname)
} else {
writef("\tdst.%s[i] = *src.%s[i].Clone()", fname, fname)
}
@@ -145,14 +155,19 @@ func gen(buf *bytes.Buffer, it *codegen.ImportTracker, typ *types.Named) {
writef("dst.%s = append(src.%s[:0:0], src.%s...)", fname, fname, fname)
}
case *types.Pointer:
if named, _ := ft.Elem().(*types.Named); named != nil && codegen.ContainsPointers(ft.Elem()) {
base := ft.Elem()
hasPtrs := codegen.ContainsPointers(base)
if named, _ := base.(*types.Named); named != nil && hasPtrs {
writef("dst.%s = src.%s.Clone()", fname, fname)
continue
}
it.Import("tailscale.com/types/ptr")
writef("if dst.%s != nil {", fname)
writef("\tdst.%s = ptr.To(*src.%s)", fname, fname)
if codegen.ContainsPointers(ft.Elem()) {
if _, isIface := base.Underlying().(*types.Interface); isIface && hasPtrs {
writef("\tdst.%s = ptr.To((*src.%s).Clone())", fname, fname)
} else if !hasPtrs {
writef("\tdst.%s = ptr.To(*src.%s)", fname, fname)
} else {
writef("\t" + `panic("TODO pointers in pointers")`)
}
writef("}")
@@ -172,18 +187,50 @@ func gen(buf *bytes.Buffer, it *codegen.ImportTracker, typ *types.Named) {
writef("if dst.%s != nil {", fname)
writef("\tdst.%s = map[%s]%s{}", fname, it.QualifiedName(ft.Key()), it.QualifiedName(elem))
writef("\tfor k, v := range src.%s {", fname)
switch elem.(type) {
switch elem := elem.Underlying().(type) {
case *types.Pointer:
writef("\t\tdst.%s[k] = v.Clone()", fname)
writef("\t\tif v == nil { dst.%s[k] = nil } else {", fname)
if base := elem.Elem().Underlying(); codegen.ContainsPointers(base) {
if _, isIface := base.(*types.Interface); isIface {
it.Import("tailscale.com/types/ptr")
writef("\t\t\tdst.%s[k] = ptr.To((*v).Clone())", fname)
} else {
writef("\t\t\tdst.%s[k] = v.Clone()", fname)
}
} else {
it.Import("tailscale.com/types/ptr")
writef("\t\t\tdst.%s[k] = ptr.To(*v)", fname)
}
writef("}")
case *types.Interface:
if cloneResultType := methodResultType(elem, "Clone"); cloneResultType != nil {
if _, isPtr := cloneResultType.(*types.Pointer); isPtr {
writef("\t\tdst.%s[k] = *(v.Clone())", fname)
} else {
writef("\t\tdst.%s[k] = v.Clone()", fname)
}
} else {
writef(`panic("%s (%v) does not have a Clone method")`, fname, elem)
}
default:
writef("\t\tdst.%s[k] = *(v.Clone())", fname)
}
writef("\t}")
writef("}")
} else {
it.Import("maps")
writef("\tdst.%s = maps.Clone(src.%s)", fname, fname)
}
case *types.Interface:
// If ft is an interface with a "Clone() ft" method, it can be used to clone the field.
// This includes scenarios where ft is a constrained type parameter.
if cloneResultType := methodResultType(ft, "Clone"); cloneResultType.Underlying() == ft {
writef("dst.%s = src.%s.Clone()", fname, fname)
continue
}
writef(`panic("%s (%v) does not have a compatible Clone method")`, fname, ft)
default:
writef(`panic("TODO: %s (%T)")`, fname, ft)
}
@@ -191,7 +238,7 @@ func gen(buf *bytes.Buffer, it *codegen.ImportTracker, typ *types.Named) {
writef("return dst")
fmt.Fprintf(buf, "}\n\n")
buf.Write(codegen.AssertStructUnchanged(t, name, "Clone", it))
buf.Write(codegen.AssertStructUnchanged(t, name, typeParams, "Clone", it))
}
// hasBasicUnderlying reports true when typ.Underlying() is a slice or a map.
@@ -203,3 +250,15 @@ func hasBasicUnderlying(typ types.Type) bool {
return false
}
}
func methodResultType(typ types.Type, method string) types.Type {
viewMethod := codegen.LookupMethod(typ, method)
if viewMethod == nil {
return nil
}
sig, ok := viewMethod.Type().(*types.Signature)
if !ok || sig.Results().Len() != 1 {
return nil
}
return sig.Results().At(0).Type()
}

56
cmd/viewer/tests/tests.go
View File

@@ -7,9 +7,12 @@ package tests
import (
"fmt"
"net/netip"
"golang.org/x/exp/constraints"
"tailscale.com/types/views"
)
//go:generate go run tailscale.com/cmd/viewer --type=StructWithPtrs,StructWithoutPtrs,Map,StructWithSlices,OnlyGetClone,StructWithEmbedded --clone-only-type=OnlyGetClone
//go:generate go run tailscale.com/cmd/viewer --type=StructWithPtrs,StructWithoutPtrs,Map,StructWithSlices,OnlyGetClone,StructWithEmbedded,GenericIntStruct,GenericNoPtrsStruct,GenericCloneableStruct --clone-only-type=OnlyGetClone
type StructWithoutPtrs struct {
Int int
@@ -25,12 +28,12 @@ type Map struct {
SlicesWithPtrs map[string][]*StructWithPtrs
SlicesWithoutPtrs map[string][]*StructWithoutPtrs
StructWithoutPtrKey map[StructWithoutPtrs]int `json:"-"`
StructWithPtr map[string]StructWithPtrs
// Unsupported views.
SliceIntPtr map[string][]*int
PointerKey map[*string]int `json:"-"`
StructWithPtrKey map[StructWithPtrs]int `json:"-"`
StructWithPtr map[string]StructWithPtrs
}
type StructWithPtrs struct {
@@ -50,12 +53,14 @@ type StructWithSlices struct {
Values []StructWithoutPtrs
ValuePointers []*StructWithoutPtrs
StructPointers []*StructWithPtrs
Structs []StructWithPtrs
Ints []*int
Slice []string
Prefixes []netip.Prefix
Data []byte
// Unsupported views.
Structs []StructWithPtrs
Ints []*int
}
type OnlyGetClone struct {
@@ -66,3 +71,46 @@ type StructWithEmbedded struct {
A *StructWithPtrs
StructWithSlices
}
type GenericIntStruct[T constraints.Integer] struct {
Value T
Pointer *T
Slice []T
Map map[string]T
// Unsupported views.
PtrSlice []*T
PtrKeyMap map[*T]string `json:"-"`
PtrValueMap map[string]*T
SliceMap map[string][]T
}
type BasicType interface {
~bool | constraints.Integer | constraints.Float | constraints.Complex | ~string
}
type GenericNoPtrsStruct[T StructWithoutPtrs | netip.Prefix | BasicType] struct {
Value T
Pointer *T
Slice []T
Map map[string]T
// Unsupported views.
PtrSlice []*T
PtrKeyMap map[*T]string `json:"-"`
PtrValueMap map[string]*T
SliceMap map[string][]T
}
type GenericCloneableStruct[T views.ViewCloner[T, V], V views.StructView[T]] struct {
Value T
Slice []T
Map map[string]T
// Unsupported views.
Pointer *T
PtrSlice []*T
PtrKeyMap map[*T]string `json:"-"`
PtrValueMap map[string]*T
SliceMap map[string][]T
}

232
cmd/viewer/tests/tests_clone.go
View File

@@ -9,7 +9,9 @@ import (
"maps"
"net/netip"
"golang.org/x/exp/constraints"
"tailscale.com/types/ptr"
"tailscale.com/types/views"
)
// Clone makes a deep copy of StructWithPtrs.
@@ -71,13 +73,21 @@ func (src *Map) Clone() *Map {
if dst.StructPtrWithPtr != nil {
dst.StructPtrWithPtr = map[string]*StructWithPtrs{}
for k, v := range src.StructPtrWithPtr {
dst.StructPtrWithPtr[k] = v.Clone()
if v == nil {
dst.StructPtrWithPtr[k] = nil
} else {
dst.StructPtrWithPtr[k] = v.Clone()
}
}
}
if dst.StructPtrWithoutPtr != nil {
dst.StructPtrWithoutPtr = map[string]*StructWithoutPtrs{}
for k, v := range src.StructPtrWithoutPtr {
dst.StructPtrWithoutPtr[k] = v.Clone()
if v == nil {
dst.StructPtrWithoutPtr[k] = nil
} else {
dst.StructPtrWithoutPtr[k] = ptr.To(*v)
}
}
}
dst.StructWithoutPtr = maps.Clone(src.StructWithoutPtr)
@@ -94,6 +104,12 @@ func (src *Map) Clone() *Map {
}
}
dst.StructWithoutPtrKey = maps.Clone(src.StructWithoutPtrKey)
if dst.StructWithPtr != nil {
dst.StructWithPtr = map[string]StructWithPtrs{}
for k, v := range src.StructWithPtr {
dst.StructWithPtr[k] = *(v.Clone())
}
}
if dst.SliceIntPtr != nil {
dst.SliceIntPtr = map[string][]*int{}
for k := range src.SliceIntPtr {
@@ -102,12 +118,6 @@ func (src *Map) Clone() *Map {
}
dst.PointerKey = maps.Clone(src.PointerKey)
dst.StructWithPtrKey = maps.Clone(src.StructWithPtrKey)
if dst.StructWithPtr != nil {
dst.StructWithPtr = map[string]StructWithPtrs{}
for k, v := range src.StructWithPtr {
dst.StructWithPtr[k] = *(v.Clone())
}
}
return dst
}
@@ -121,10 +131,10 @@ var _MapCloneNeedsRegeneration = Map(struct {
SlicesWithPtrs map[string][]*StructWithPtrs
SlicesWithoutPtrs map[string][]*StructWithoutPtrs
StructWithoutPtrKey map[StructWithoutPtrs]int
StructWithPtr map[string]StructWithPtrs
SliceIntPtr map[string][]*int
PointerKey map[*string]int
StructWithPtrKey map[StructWithPtrs]int
StructWithPtr map[string]StructWithPtrs
}{})
// Clone makes a deep copy of StructWithSlices.
@@ -139,15 +149,26 @@ func (src *StructWithSlices) Clone() *StructWithSlices {
if src.ValuePointers != nil {
dst.ValuePointers = make([]*StructWithoutPtrs, len(src.ValuePointers))
for i := range dst.ValuePointers {
dst.ValuePointers[i] = src.ValuePointers[i].Clone()
if src.ValuePointers[i] == nil {
dst.ValuePointers[i] = nil
} else {
dst.ValuePointers[i] = ptr.To(*src.ValuePointers[i])
}
}
}
if src.StructPointers != nil {
dst.StructPointers = make([]*StructWithPtrs, len(src.StructPointers))
for i := range dst.StructPointers {
dst.StructPointers[i] = src.StructPointers[i].Clone()
if src.StructPointers[i] == nil {
dst.StructPointers[i] = nil
} else {
dst.StructPointers[i] = src.StructPointers[i].Clone()
}
}
}
dst.Slice = append(src.Slice[:0:0], src.Slice...)
dst.Prefixes = append(src.Prefixes[:0:0], src.Prefixes...)
dst.Data = append(src.Data[:0:0], src.Data...)
if src.Structs != nil {
dst.Structs = make([]StructWithPtrs, len(src.Structs))
for i := range dst.Structs {
@@ -164,9 +185,6 @@ func (src *StructWithSlices) Clone() *StructWithSlices {
}
}
}
dst.Slice = append(src.Slice[:0:0], src.Slice...)
dst.Prefixes = append(src.Prefixes[:0:0], src.Prefixes...)
dst.Data = append(src.Data[:0:0], src.Data...)
return dst
}
@@ -175,11 +193,11 @@ var _StructWithSlicesCloneNeedsRegeneration = StructWithSlices(struct {
Values []StructWithoutPtrs
ValuePointers []*StructWithoutPtrs
StructPointers []*StructWithPtrs
Structs []StructWithPtrs
Ints []*int
Slice []string
Prefixes []netip.Prefix
Data []byte
Structs []StructWithPtrs
Ints []*int
}{})
// Clone makes a deep copy of OnlyGetClone.
@@ -216,3 +234,185 @@ var _StructWithEmbeddedCloneNeedsRegeneration = StructWithEmbedded(struct {
A *StructWithPtrs
StructWithSlices
}{})
// Clone makes a deep copy of GenericIntStruct.
// The result aliases no memory with the original.
func (src *GenericIntStruct[T]) Clone() *GenericIntStruct[T] {
if src == nil {
return nil
}
dst := new(GenericIntStruct[T])
*dst = *src
if dst.Pointer != nil {
dst.Pointer = ptr.To(*src.Pointer)
}
dst.Slice = append(src.Slice[:0:0], src.Slice...)
dst.Map = maps.Clone(src.Map)
if src.PtrSlice != nil {
dst.PtrSlice = make([]*T, len(src.PtrSlice))
for i := range dst.PtrSlice {
if src.PtrSlice[i] == nil {
dst.PtrSlice[i] = nil
} else {
dst.PtrSlice[i] = ptr.To(*src.PtrSlice[i])
}
}
}
dst.PtrKeyMap = maps.Clone(src.PtrKeyMap)
if dst.PtrValueMap != nil {
dst.PtrValueMap = map[string]*T{}
for k, v := range src.PtrValueMap {
if v == nil {
dst.PtrValueMap[k] = nil
} else {
dst.PtrValueMap[k] = ptr.To(*v)
}
}
}
if dst.SliceMap != nil {
dst.SliceMap = map[string][]T{}
for k := range src.SliceMap {
dst.SliceMap[k] = append([]T{}, src.SliceMap[k]...)
}
}
return dst
}
// A compilation failure here means this code must be regenerated, with the command at the top of this file.
func _GenericIntStructCloneNeedsRegeneration[T constraints.Integer](GenericIntStruct[T]) {
_GenericIntStructCloneNeedsRegeneration(struct {
Value T
Pointer *T
Slice []T
Map map[string]T
PtrSlice []*T
PtrKeyMap map[*T]string `json:"-"`
PtrValueMap map[string]*T
SliceMap map[string][]T
}{})
}
// Clone makes a deep copy of GenericNoPtrsStruct.
// The result aliases no memory with the original.
func (src *GenericNoPtrsStruct[T]) Clone() *GenericNoPtrsStruct[T] {
if src == nil {
return nil
}
dst := new(GenericNoPtrsStruct[T])
*dst = *src
if dst.Pointer != nil {
dst.Pointer = ptr.To(*src.Pointer)
}
dst.Slice = append(src.Slice[:0:0], src.Slice...)
dst.Map = maps.Clone(src.Map)
if src.PtrSlice != nil {
dst.PtrSlice = make([]*T, len(src.PtrSlice))
for i := range dst.PtrSlice {
if src.PtrSlice[i] == nil {
dst.PtrSlice[i] = nil
} else {
dst.PtrSlice[i] = ptr.To(*src.PtrSlice[i])
}
}
}
dst.PtrKeyMap = maps.Clone(src.PtrKeyMap)
if dst.PtrValueMap != nil {
dst.PtrValueMap = map[string]*T{}
for k, v := range src.PtrValueMap {
if v == nil {
dst.PtrValueMap[k] = nil
} else {
dst.PtrValueMap[k] = ptr.To(*v)
}
}
}
if dst.SliceMap != nil {
dst.SliceMap = map[string][]T{}
for k := range src.SliceMap {
dst.SliceMap[k] = append([]T{}, src.SliceMap[k]...)
}
}
return dst
}
// A compilation failure here means this code must be regenerated, with the command at the top of this file.
func _GenericNoPtrsStructCloneNeedsRegeneration[T StructWithoutPtrs | netip.Prefix | BasicType](GenericNoPtrsStruct[T]) {
_GenericNoPtrsStructCloneNeedsRegeneration(struct {
Value T
Pointer *T
Slice []T
Map map[string]T
PtrSlice []*T
PtrKeyMap map[*T]string `json:"-"`
PtrValueMap map[string]*T
SliceMap map[string][]T
}{})
}
// Clone makes a deep copy of GenericCloneableStruct.
// The result aliases no memory with the original.
func (src *GenericCloneableStruct[T, V]) Clone() *GenericCloneableStruct[T, V] {
if src == nil {
return nil
}
dst := new(GenericCloneableStruct[T, V])
*dst = *src
dst.Value = src.Value.Clone()
if src.Slice != nil {
dst.Slice = make([]T, len(src.Slice))
for i := range dst.Slice {
dst.Slice[i] = src.Slice[i].Clone()
}
}
if dst.Map != nil {
dst.Map = map[string]T{}
for k, v := range src.Map {
dst.Map[k] = v.Clone()
}
}
if dst.Pointer != nil {
dst.Pointer = ptr.To((*src.Pointer).Clone())
}
if src.PtrSlice != nil {
dst.PtrSlice = make([]*T, len(src.PtrSlice))
for i := range dst.PtrSlice {
if src.PtrSlice[i] == nil {
dst.PtrSlice[i] = nil
} else {
dst.PtrSlice[i] = ptr.To((*src.PtrSlice[i]).Clone())
}
}
}
dst.PtrKeyMap = maps.Clone(src.PtrKeyMap)
if dst.PtrValueMap != nil {
dst.PtrValueMap = map[string]*T{}
for k, v := range src.PtrValueMap {
if v == nil {
dst.PtrValueMap[k] = nil
} else {
dst.PtrValueMap[k] = ptr.To((*v).Clone())
}
}
}
if dst.SliceMap != nil {
dst.SliceMap = map[string][]T{}
for k := range src.SliceMap {
dst.SliceMap[k] = append([]T{}, src.SliceMap[k]...)
}
}
return dst
}
// A compilation failure here means this code must be regenerated, with the command at the top of this file.
func _GenericCloneableStructCloneNeedsRegeneration[T views.ViewCloner[T, V], V views.StructView[T]](GenericCloneableStruct[T, V]) {
_GenericCloneableStructCloneNeedsRegeneration(struct {
Value T
Slice []T
Map map[string]T
Pointer *T
PtrSlice []*T
PtrKeyMap map[*T]string `json:"-"`
PtrValueMap map[string]*T
SliceMap map[string][]T
}{})
}

246
cmd/viewer/tests/tests_view.go
View File

@@ -10,10 +10,11 @@ import (
"errors"
"net/netip"
"golang.org/x/exp/constraints"
"tailscale.com/types/views"
)
//go:generate go run tailscale.com/cmd/cloner -clonefunc=false -type=StructWithPtrs,StructWithoutPtrs,Map,StructWithSlices,OnlyGetClone,StructWithEmbedded
//go:generate go run tailscale.com/cmd/cloner -clonefunc=false -type=StructWithPtrs,StructWithoutPtrs,Map,StructWithSlices,OnlyGetClone,StructWithEmbedded,GenericIntStruct,GenericNoPtrsStruct,GenericCloneableStruct
// View returns a readonly view of StructWithPtrs.
func (p *StructWithPtrs) View() StructWithPtrsView {
@@ -221,15 +222,15 @@ func (v MapView) SlicesWithoutPtrs() views.MapFn[string, []*StructWithoutPtrs, v
func (v MapView) StructWithoutPtrKey() views.Map[StructWithoutPtrs, int] {
return views.MapOf(v.ж.StructWithoutPtrKey)
}
func (v MapView) SliceIntPtr() map[string][]*int { panic("unsupported") }
func (v MapView) PointerKey() map[*string]int { panic("unsupported") }
func (v MapView) StructWithPtrKey() map[StructWithPtrs]int { panic("unsupported") }
func (v MapView) StructWithPtr() views.MapFn[string, StructWithPtrs, StructWithPtrsView] {
return views.MapFnOf(v.ж.StructWithPtr, func(t StructWithPtrs) StructWithPtrsView {
return t.View()
})
}
func (v MapView) SliceIntPtr() map[string][]*int { panic("unsupported") }
func (v MapView) PointerKey() map[*string]int { panic("unsupported") }
func (v MapView) StructWithPtrKey() map[StructWithPtrs]int { panic("unsupported") }
// A compilation failure here means this code must be regenerated, with the command at the top of this file.
var _MapViewNeedsRegeneration = Map(struct {
@@ -241,10 +242,10 @@ var _MapViewNeedsRegeneration = Map(struct {
SlicesWithPtrs map[string][]*StructWithPtrs
SlicesWithoutPtrs map[string][]*StructWithoutPtrs
StructWithoutPtrKey map[StructWithoutPtrs]int
StructWithPtr map[string]StructWithPtrs
SliceIntPtr map[string][]*int
PointerKey map[*string]int
StructWithPtrKey map[StructWithPtrs]int
StructWithPtr map[string]StructWithPtrs
}{})
// View returns a readonly view of StructWithSlices.
@@ -301,24 +302,24 @@ func (v StructWithSlicesView) ValuePointers() views.SliceView[*StructWithoutPtrs
func (v StructWithSlicesView) StructPointers() views.SliceView[*StructWithPtrs, StructWithPtrsView] {
return views.SliceOfViews[*StructWithPtrs, StructWithPtrsView](v.ж.StructPointers)
}
func (v StructWithSlicesView) Structs() StructWithPtrs { panic("unsupported") }
func (v StructWithSlicesView) Ints() *int { panic("unsupported") }
func (v StructWithSlicesView) Slice() views.Slice[string] { return views.SliceOf(v.ж.Slice) }
func (v StructWithSlicesView) Prefixes() views.Slice[netip.Prefix] {
return views.SliceOf(v.ж.Prefixes)
}
func (v StructWithSlicesView) Data() views.ByteSlice[[]byte] { return views.ByteSliceOf(v.ж.Data) }
func (v StructWithSlicesView) Structs() StructWithPtrs { panic("unsupported") }
func (v StructWithSlicesView) Ints() *int { panic("unsupported") }
// A compilation failure here means this code must be regenerated, with the command at the top of this file.
var _StructWithSlicesViewNeedsRegeneration = StructWithSlices(struct {
Values []StructWithoutPtrs
ValuePointers []*StructWithoutPtrs
StructPointers []*StructWithPtrs
Structs []StructWithPtrs
Ints []*int
Slice []string
Prefixes []netip.Prefix
Data []byte
Structs []StructWithPtrs
Ints []*int
}{})
// View returns a readonly view of StructWithEmbedded.
@@ -376,3 +377,230 @@ var _StructWithEmbeddedViewNeedsRegeneration = StructWithEmbedded(struct {
A *StructWithPtrs
StructWithSlices
}{})
// View returns a readonly view of GenericIntStruct.
func (p *GenericIntStruct[T]) View() GenericIntStructView[T] {
return GenericIntStructView[T]{ж: p}
}
// GenericIntStructView[T] provides a read-only view over GenericIntStruct[T].
//
// Its methods should only be called if `Valid()` returns true.
type GenericIntStructView[T constraints.Integer] struct {
// ж is the underlying mutable value, named with a hard-to-type
// character that looks pointy like a pointer.
// It is named distinctively to make you think of how dangerous it is to escape
// to callers. You must not let callers be able to mutate it.
ж *GenericIntStruct[T]
}
// Valid reports whether underlying value is non-nil.
func (v GenericIntStructView[T]) Valid() bool { return v.ж != nil }
// AsStruct returns a clone of the underlying value which aliases no memory with
// the original.
func (v GenericIntStructView[T]) AsStruct() *GenericIntStruct[T] {
if v.ж == nil {
return nil
}
return v.ж.Clone()
}
func (v GenericIntStructView[T]) MarshalJSON() ([]byte, error) { return json.Marshal(v.ж) }
func (v *GenericIntStructView[T]) UnmarshalJSON(b []byte) error {
if v.ж != nil {
return errors.New("already initialized")
}
if len(b) == 0 {
return nil
}
var x GenericIntStruct[T]
if err := json.Unmarshal(b, &x); err != nil {
return err
}
v.ж = &x
return nil
}
func (v GenericIntStructView[T]) Value() T { return v.ж.Value }
func (v GenericIntStructView[T]) Pointer() *T {
if v.ж.Pointer == nil {
return nil
}
x := *v.ж.Pointer
return &x
}
func (v GenericIntStructView[T]) Slice() views.Slice[T] { return views.SliceOf(v.ж.Slice) }
func (v GenericIntStructView[T]) Map() views.Map[string, T] { return views.MapOf(v.ж.Map) }
func (v GenericIntStructView[T]) PtrSlice() *T { panic("unsupported") }
func (v GenericIntStructView[T]) PtrKeyMap() map[*T]string { panic("unsupported") }
func (v GenericIntStructView[T]) PtrValueMap() map[string]*T { panic("unsupported") }
func (v GenericIntStructView[T]) SliceMap() map[string][]T { panic("unsupported") }
// A compilation failure here means this code must be regenerated, with the command at the top of this file.
func _GenericIntStructViewNeedsRegeneration[T constraints.Integer](GenericIntStruct[T]) {
_GenericIntStructViewNeedsRegeneration(struct {
Value T
Pointer *T
Slice []T
Map map[string]T
PtrSlice []*T
PtrKeyMap map[*T]string `json:"-"`
PtrValueMap map[string]*T
SliceMap map[string][]T
}{})
}
// View returns a readonly view of GenericNoPtrsStruct.
func (p *GenericNoPtrsStruct[T]) View() GenericNoPtrsStructView[T] {
return GenericNoPtrsStructView[T]{ж: p}
}
// GenericNoPtrsStructView[T] provides a read-only view over GenericNoPtrsStruct[T].
//
// Its methods should only be called if `Valid()` returns true.
type GenericNoPtrsStructView[T StructWithoutPtrs | netip.Prefix | BasicType] struct {
// ж is the underlying mutable value, named with a hard-to-type
// character that looks pointy like a pointer.
// It is named distinctively to make you think of how dangerous it is to escape
// to callers. You must not let callers be able to mutate it.
ж *GenericNoPtrsStruct[T]
}
// Valid reports whether underlying value is non-nil.
func (v GenericNoPtrsStructView[T]) Valid() bool { return v.ж != nil }
// AsStruct returns a clone of the underlying value which aliases no memory with
// the original.
func (v GenericNoPtrsStructView[T]) AsStruct() *GenericNoPtrsStruct[T] {
if v.ж == nil {
return nil
}
return v.ж.Clone()
}
func (v GenericNoPtrsStructView[T]) MarshalJSON() ([]byte, error) { return json.Marshal(v.ж) }
func (v *GenericNoPtrsStructView[T]) UnmarshalJSON(b []byte) error {
if v.ж != nil {
return errors.New("already initialized")
}
if len(b) == 0 {
return nil
}
var x GenericNoPtrsStruct[T]
if err := json.Unmarshal(b, &x); err != nil {
return err
}
v.ж = &x
return nil
}
func (v GenericNoPtrsStructView[T]) Value() T { return v.ж.Value }
func (v GenericNoPtrsStructView[T]) Pointer() *T {
if v.ж.Pointer == nil {
return nil
}
x := *v.ж.Pointer
return &x
}
func (v GenericNoPtrsStructView[T]) Slice() views.Slice[T] { return views.SliceOf(v.ж.Slice) }
func (v GenericNoPtrsStructView[T]) Map() views.Map[string, T] { return views.MapOf(v.ж.Map) }
func (v GenericNoPtrsStructView[T]) PtrSlice() *T { panic("unsupported") }
func (v GenericNoPtrsStructView[T]) PtrKeyMap() map[*T]string { panic("unsupported") }
func (v GenericNoPtrsStructView[T]) PtrValueMap() map[string]*T { panic("unsupported") }
func (v GenericNoPtrsStructView[T]) SliceMap() map[string][]T { panic("unsupported") }
// A compilation failure here means this code must be regenerated, with the command at the top of this file.
func _GenericNoPtrsStructViewNeedsRegeneration[T StructWithoutPtrs | netip.Prefix | BasicType](GenericNoPtrsStruct[T]) {
_GenericNoPtrsStructViewNeedsRegeneration(struct {
Value T
Pointer *T
Slice []T
Map map[string]T
PtrSlice []*T
PtrKeyMap map[*T]string `json:"-"`
PtrValueMap map[string]*T
SliceMap map[string][]T
}{})
}
// View returns a readonly view of GenericCloneableStruct.
func (p *GenericCloneableStruct[T, V]) View() GenericCloneableStructView[T, V] {
return GenericCloneableStructView[T, V]{ж: p}
}
// GenericCloneableStructView[T, V] provides a read-only view over GenericCloneableStruct[T, V].
//
// Its methods should only be called if `Valid()` returns true.
type GenericCloneableStructView[T views.ViewCloner[T, V], V views.StructView[T]] struct {
// ж is the underlying mutable value, named with a hard-to-type
// character that looks pointy like a pointer.
// It is named distinctively to make you think of how dangerous it is to escape
// to callers. You must not let callers be able to mutate it.
ж *GenericCloneableStruct[T, V]
}
// Valid reports whether underlying value is non-nil.
func (v GenericCloneableStructView[T, V]) Valid() bool { return v.ж != nil }
// AsStruct returns a clone of the underlying value which aliases no memory with
// the original.
func (v GenericCloneableStructView[T, V]) AsStruct() *GenericCloneableStruct[T, V] {
if v.ж == nil {
return nil
}
return v.ж.Clone()
}
func (v GenericCloneableStructView[T, V]) MarshalJSON() ([]byte, error) { return json.Marshal(v.ж) }
func (v *GenericCloneableStructView[T, V]) UnmarshalJSON(b []byte) error {
if v.ж != nil {
return errors.New("already initialized")
}
if len(b) == 0 {
return nil
}
var x GenericCloneableStruct[T, V]
if err := json.Unmarshal(b, &x); err != nil {
return err
}
v.ж = &x
return nil
}
func (v GenericCloneableStructView[T, V]) Value() V { return v.ж.Value.View() }
func (v GenericCloneableStructView[T, V]) Slice() views.SliceView[T, V] {
return views.SliceOfViews[T, V](v.ж.Slice)
}
func (v GenericCloneableStructView[T, V]) Map() views.MapFn[string, T, V] {
return views.MapFnOf(v.ж.Map, func(t T) V {
return t.View()
})
}
func (v GenericCloneableStructView[T, V]) Pointer() map[string]T { panic("unsupported") }
func (v GenericCloneableStructView[T, V]) PtrSlice() *T { panic("unsupported") }
func (v GenericCloneableStructView[T, V]) PtrKeyMap() map[*T]string { panic("unsupported") }
func (v GenericCloneableStructView[T, V]) PtrValueMap() map[string]*T { panic("unsupported") }
func (v GenericCloneableStructView[T, V]) SliceMap() map[string][]T { panic("unsupported") }
// A compilation failure here means this code must be regenerated, with the command at the top of this file.
func _GenericCloneableStructViewNeedsRegeneration[T views.ViewCloner[T, V], V views.StructView[T]](GenericCloneableStruct[T, V]) {
_GenericCloneableStructViewNeedsRegeneration(struct {
Value T
Slice []T
Map map[string]T
Pointer *T
PtrSlice []*T
PtrKeyMap map[*T]string `json:"-"`
PtrValueMap map[string]*T
SliceMap map[string][]T
}{})
}

182
cmd/viewer/viewer.go
View File

@@ -20,43 +20,43 @@ import (
const viewTemplateStr = `{{define "common"}}
// View returns a readonly view of {{.StructName}}.
func (p *{{.StructName}}) View() {{.ViewName}} {
return {{.ViewName}}{ж: p}
func (p *{{.StructName}}{{.TypeParamNames}}) View() {{.ViewName}}{{.TypeParamNames}} {
return {{.ViewName}}{{.TypeParamNames}}{ж: p}
}
// {{.ViewName}} provides a read-only view over {{.StructName}}.
// {{.ViewName}}{{.TypeParamNames}} provides a read-only view over {{.StructName}}{{.TypeParamNames}}.
//
// Its methods should only be called if ` + "`Valid()`" + ` returns true.
type {{.ViewName}} struct {
type {{.ViewName}}{{.TypeParams}} struct {
// ж is the underlying mutable value, named with a hard-to-type
// character that looks pointy like a pointer.
// It is named distinctively to make you think of how dangerous it is to escape
// to callers. You must not let callers be able to mutate it.
ж *{{.StructName}}
ж *{{.StructName}}{{.TypeParamNames}}
}
// Valid reports whether underlying value is non-nil.
func (v {{.ViewName}}) Valid() bool { return v.ж != nil }
func (v {{.ViewName}}{{.TypeParamNames}}) Valid() bool { return v.ж != nil }
// AsStruct returns a clone of the underlying value which aliases no memory with
// the original.
func (v {{.ViewName}}) AsStruct() *{{.StructName}}{
func (v {{.ViewName}}{{.TypeParamNames}}) AsStruct() *{{.StructName}}{{.TypeParamNames}}{
if v.ж == nil {
return nil
}
return v.ж.Clone()
}
func (v {{.ViewName}}) MarshalJSON() ([]byte, error) { return json.Marshal(v.ж) }
func (v {{.ViewName}}{{.TypeParamNames}}) MarshalJSON() ([]byte, error) { return json.Marshal(v.ж) }
func (v *{{.ViewName}}) UnmarshalJSON(b []byte) error {
func (v *{{.ViewName}}{{.TypeParamNames}}) UnmarshalJSON(b []byte) error {
if v.ж != nil {
return errors.New("already initialized")
}
if len(b) == 0 {
return nil
}
var x {{.StructName}}
var x {{.StructName}}{{.TypeParamNames}}
if err := json.Unmarshal(b, &x); err != nil {
return err
}
@@ -65,17 +65,17 @@ func (v *{{.ViewName}}) UnmarshalJSON(b []byte) error {
}
{{end}}
{{define "valueField"}}func (v {{.ViewName}}) {{.FieldName}}() {{.FieldType}} { return v.ж.{{.FieldName}} }
{{define "valueField"}}func (v {{.ViewName}}{{.TypeParamNames}}) {{.FieldName}}() {{.FieldType}} { return v.ж.{{.FieldName}} }
{{end}}
{{define "byteSliceField"}}func (v {{.ViewName}}) {{.FieldName}}() views.ByteSlice[{{.FieldType}}] { return views.ByteSliceOf(v.ж.{{.FieldName}}) }
{{define "byteSliceField"}}func (v {{.ViewName}}{{.TypeParamNames}}) {{.FieldName}}() views.ByteSlice[{{.FieldType}}] { return views.ByteSliceOf(v.ж.{{.FieldName}}) }
{{end}}
{{define "sliceField"}}func (v {{.ViewName}}) {{.FieldName}}() views.Slice[{{.FieldType}}] { return views.SliceOf(v.ж.{{.FieldName}}) }
{{define "sliceField"}}func (v {{.ViewName}}{{.TypeParamNames}}) {{.FieldName}}() views.Slice[{{.FieldType}}] { return views.SliceOf(v.ж.{{.FieldName}}) }
{{end}}
{{define "viewSliceField"}}func (v {{.ViewName}}) {{.FieldName}}() views.SliceView[{{.FieldType}},{{.FieldViewName}}] { return views.SliceOfViews[{{.FieldType}},{{.FieldViewName}}](v.ж.{{.FieldName}}) }
{{define "viewSliceField"}}func (v {{.ViewName}}{{.TypeParamNames}}) {{.FieldName}}() views.SliceView[{{.FieldType}},{{.FieldViewName}}] { return views.SliceOfViews[{{.FieldType}},{{.FieldViewName}}](v.ж.{{.FieldName}}) }
{{end}}
{{define "viewField"}}func (v {{.ViewName}}) {{.FieldName}}() {{.FieldType}}View { return v.ж.{{.FieldName}}.View() }
{{define "viewField"}}func (v {{.ViewName}}{{.TypeParamNames}}) {{.FieldName}}() {{.FieldViewName}} { return v.ж.{{.FieldName}}.View() }
{{end}}
{{define "valuePointerField"}}func (v {{.ViewName}}) {{.FieldName}}() {{.FieldType}} {
{{define "valuePointerField"}}func (v {{.ViewName}}{{.TypeParamNames}}) {{.FieldName}}() {{.FieldType}} {
if v.ж.{{.FieldName}} == nil {
return nil
}
@@ -85,21 +85,21 @@ func (v *{{.ViewName}}) UnmarshalJSON(b []byte) error {
{{end}}
{{define "mapField"}}
func(v {{.ViewName}}) {{.FieldName}}() views.Map[{{.MapKeyType}},{{.MapValueType}}] { return views.MapOf(v.ж.{{.FieldName}})}
func(v {{.ViewName}}{{.TypeParamNames}}) {{.FieldName}}() views.Map[{{.MapKeyType}},{{.MapValueType}}] { return views.MapOf(v.ж.{{.FieldName}})}
{{end}}
{{define "mapFnField"}}
func(v {{.ViewName}}) {{.FieldName}}() views.MapFn[{{.MapKeyType}},{{.MapValueType}},{{.MapValueView}}] { return views.MapFnOf(v.ж.{{.FieldName}}, func (t {{.MapValueType}}) {{.MapValueView}} {
func(v {{.ViewName}}{{.TypeParamNames}}) {{.FieldName}}() views.MapFn[{{.MapKeyType}},{{.MapValueType}},{{.MapValueView}}] { return views.MapFnOf(v.ж.{{.FieldName}}, func (t {{.MapValueType}}) {{.MapValueView}} {
return {{.MapFn}}
})}
{{end}}
{{define "mapSliceField"}}
func(v {{.ViewName}}) {{.FieldName}}() views.MapSlice[{{.MapKeyType}},{{.MapValueType}}] { return views.MapSliceOf(v.ж.{{.FieldName}}) }
func(v {{.ViewName}}{{.TypeParamNames}}) {{.FieldName}}() views.MapSlice[{{.MapKeyType}},{{.MapValueType}}] { return views.MapSliceOf(v.ж.{{.FieldName}}) }
{{end}}
{{define "unsupportedField"}}func(v {{.ViewName}}) {{.FieldName}}() {{.FieldType}} {panic("unsupported")}
{{define "unsupportedField"}}func(v {{.ViewName}}{{.TypeParamNames}}) {{.FieldName}}() {{.FieldType}} {panic("unsupported")}
{{end}}
{{define "stringFunc"}}func(v {{.ViewName}}) String() string { return v.ж.String() }
{{define "stringFunc"}}func(v {{.ViewName}}{{.TypeParamNames}}) String() string { return v.ж.String() }
{{end}}
{{define "equalFunc"}}func(v {{.ViewName}}) Equal(v2 {{.ViewName}}) bool { return v.ж.Equal(v2.ж) }
{{define "equalFunc"}}func(v {{.ViewName}}{{.TypeParamNames}}) Equal(v2 {{.ViewName}}{{.TypeParamNames}}) bool { return v.ж.Equal(v2.ж) }
{{end}}
`
@@ -131,8 +131,11 @@ func genView(buf *bytes.Buffer, it *codegen.ImportTracker, typ *types.Named, thi
it.Import("errors")
args := struct {
StructName string
ViewName string
StructName string
ViewName string
TypeParams string // e.g. [T constraints.Integer]
TypeParamNames string // e.g. [T]
FieldName string
FieldType string
FieldViewName string
@@ -143,9 +146,12 @@ func genView(buf *bytes.Buffer, it *codegen.ImportTracker, typ *types.Named, thi
MapFn string
}{
StructName: typ.Obj().Name(),
ViewName: typ.Obj().Name() + "View",
ViewName: typ.Origin().Obj().Name() + "View",
}
typeParams := typ.Origin().TypeParams()
args.TypeParams, args.TypeParamNames = codegen.FormatTypeParams(typeParams, it)
writeTemplate := func(name string) {
if err := viewTemplate.ExecuteTemplate(buf, name, args); err != nil {
log.Fatal(err)
@@ -182,19 +188,35 @@ func genView(buf *bytes.Buffer, it *codegen.ImportTracker, typ *types.Named, thi
it.Import("tailscale.com/types/views")
shallow, deep, base := requiresCloning(elem)
if deep {
if _, isPtr := elem.(*types.Pointer); isPtr {
args.FieldViewName = it.QualifiedName(base) + "View"
writeTemplate("viewSliceField")
} else {
writeTemplate("unsupportedField")
switch elem.Underlying().(type) {
case *types.Pointer:
if _, isIface := base.Underlying().(*types.Interface); !isIface {
args.FieldViewName = appendNameSuffix(it.QualifiedName(base), "View")
writeTemplate("viewSliceField")
} else {
writeTemplate("unsupportedField")
}
continue
case *types.Interface:
if viewType := viewTypeForValueType(elem); viewType != nil {
args.FieldViewName = it.QualifiedName(viewType)
writeTemplate("viewSliceField")
continue
}
}
writeTemplate("unsupportedField")
continue
} else if shallow {
if _, isBasic := base.(*types.Basic); isBasic {
switch base.Underlying().(type) {
case *types.Basic, *types.Interface:
writeTemplate("unsupportedField")
} else {
args.FieldViewName = it.QualifiedName(base) + "View"
writeTemplate("viewSliceField")
default:
if _, isIface := base.Underlying().(*types.Interface); !isIface {
args.FieldViewName = appendNameSuffix(it.QualifiedName(base), "View")
writeTemplate("viewSliceField")
} else {
writeTemplate("unsupportedField")
}
}
continue
}
@@ -205,6 +227,7 @@ func genView(buf *bytes.Buffer, it *codegen.ImportTracker, typ *types.Named, thi
strucT := underlying
args.FieldType = it.QualifiedName(fieldType)
if codegen.ContainsPointers(strucT) {
args.FieldViewName = appendNameSuffix(args.FieldType, "View")
writeTemplate("viewField")
continue
}
@@ -229,7 +252,7 @@ func genView(buf *bytes.Buffer, it *codegen.ImportTracker, typ *types.Named, thi
args.MapFn = "t.View()"
template = "mapFnField"
args.MapValueType = it.QualifiedName(mElem)
args.MapValueView = args.MapValueType + "View"
args.MapValueView = appendNameSuffix(args.MapValueType, "View")
} else {
template = "mapField"
args.MapValueType = it.QualifiedName(mElem)
@@ -249,15 +272,20 @@ func genView(buf *bytes.Buffer, it *codegen.ImportTracker, typ *types.Named, thi
case *types.Pointer:
ptr := x
pElem := ptr.Elem()
switch pElem.(type) {
case *types.Struct, *types.Named:
ptrType := it.QualifiedName(ptr)
viewType := it.QualifiedName(pElem) + "View"
args.MapFn = fmt.Sprintf("views.SliceOfViews[%v,%v](t)", ptrType, viewType)
args.MapValueView = fmt.Sprintf("views.SliceView[%v,%v]", ptrType, viewType)
args.MapValueType = "[]" + ptrType
template = "mapFnField"
default:
template = "unsupportedField"
if _, isIface := pElem.Underlying().(*types.Interface); !isIface {
switch pElem.(type) {
case *types.Struct, *types.Named:
ptrType := it.QualifiedName(ptr)
viewType := appendNameSuffix(it.QualifiedName(pElem), "View")
args.MapFn = fmt.Sprintf("views.SliceOfViews[%v,%v](t)", ptrType, viewType)
args.MapValueView = fmt.Sprintf("views.SliceView[%v,%v]", ptrType, viewType)
args.MapValueType = "[]" + ptrType
template = "mapFnField"
default:
template = "unsupportedField"
}
} else {
template = "unsupportedField"
}
default:
@@ -266,13 +294,29 @@ func genView(buf *bytes.Buffer, it *codegen.ImportTracker, typ *types.Named, thi
case *types.Pointer:
ptr := u
pElem := ptr.Elem()
switch pElem.(type) {
case *types.Struct, *types.Named:
args.MapValueType = it.QualifiedName(ptr)
args.MapValueView = it.QualifiedName(pElem) + "View"
if _, isIface := pElem.Underlying().(*types.Interface); !isIface {
switch pElem.(type) {
case *types.Struct, *types.Named:
args.MapValueType = it.QualifiedName(ptr)
args.MapValueView = appendNameSuffix(it.QualifiedName(pElem), "View")
args.MapFn = "t.View()"
template = "mapFnField"
default:
template = "unsupportedField"
}
} else {
template = "unsupportedField"
}
case *types.Interface, *types.TypeParam:
if viewType := viewTypeForValueType(u); viewType != nil {
args.MapValueType = it.QualifiedName(u)
args.MapValueView = it.QualifiedName(viewType)
args.MapFn = "t.View()"
template = "mapFnField"
default:
} else if !codegen.ContainsPointers(u) {
args.MapValueType = it.QualifiedName(mElem)
template = "mapField"
} else {
template = "unsupportedField"
}
default:
@@ -283,14 +327,28 @@ func genView(buf *bytes.Buffer, it *codegen.ImportTracker, typ *types.Named, thi
case *types.Pointer:
ptr := underlying
_, deep, base := requiresCloning(ptr)
if deep {
args.FieldType = it.QualifiedName(base)
writeTemplate("viewField")
if _, isIface := base.Underlying().(*types.Interface); !isIface {
args.FieldType = it.QualifiedName(base)
args.FieldViewName = appendNameSuffix(args.FieldType, "View")
writeTemplate("viewField")
} else {
writeTemplate("unsupportedField")
}
} else {
args.FieldType = it.QualifiedName(ptr)
writeTemplate("valuePointerField")
}
continue
case *types.Interface:
// If fieldType is an interface with a "View() {ViewType}" method, it can be used to clone the field.
// This includes scenarios where fieldType is a constrained type parameter.
if viewType := viewTypeForValueType(underlying); viewType != nil {
args.FieldViewName = it.QualifiedName(viewType)
writeTemplate("viewField")
continue
}
}
writeTemplate("unsupportedField")
}
@@ -318,7 +376,27 @@ func genView(buf *bytes.Buffer, it *codegen.ImportTracker, typ *types.Named, thi
}
}
fmt.Fprintf(buf, "\n")
buf.Write(codegen.AssertStructUnchanged(t, args.StructName, "View", it))
buf.Write(codegen.AssertStructUnchanged(t, args.StructName, typeParams, "View", it))
}
func appendNameSuffix(name, suffix string) string {
if idx := strings.IndexRune(name, '['); idx != -1 {
// Insert suffix after the type name, but before type parameters.
return name[:idx] + suffix + name[idx:]
}
return name + suffix
}
func viewTypeForValueType(typ types.Type) types.Type {
viewMethod := codegen.LookupMethod(typ, "View")
if viewMethod == nil {
return nil
}
sig, ok := viewMethod.Type().(*types.Signature)
if !ok || sig.Results().Len() != 1 {
return nil
}
return sig.Results().At(0).Type()
}
var (