cmd/api: support type parameters
Fixes #48706
Change-Id: If0f8d0b49300027e3b2b46f6870302acf2e00f4e
Reviewed-on: https://go-review.googlesource.com/c/go/+/354612
Trust: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>
TryBot-Result: Go Bot <gobot@golang.org>
diff --git a/src/cmd/api/goapi.go b/src/cmd/api/goapi.go
index 43c761a..eca113a 100644
--- a/src/cmd/api/goapi.go
+++ b/src/cmd/api/goapi.go
@@ -706,6 +706,36 @@
return list
}
+// sortedEmbeddeds returns constraint types embedded in an
+// interface. It does not include embedded interface types or methods.
+func (w *Walker) sortedEmbeddeds(typ *types.Interface) []string {
+ n := typ.NumEmbeddeds()
+ list := make([]string, 0, n)
+ for i := 0; i < n; i++ {
+ emb := typ.EmbeddedType(i)
+ switch emb := emb.(type) {
+ case *types.Interface:
+ list = append(list, w.sortedEmbeddeds(emb)...)
+ case *types.Union:
+ var buf bytes.Buffer
+ nu := emb.Len()
+ for i := 0; i < nu; i++ {
+ if i > 0 {
+ buf.WriteString(" | ")
+ }
+ term := emb.Term(i)
+ if term.Tilde() {
+ buf.WriteByte('~')
+ }
+ w.writeType(&buf, term.Type())
+ }
+ list = append(list, buf.String())
+ }
+ }
+ sort.Strings(list)
+ return list
+}
+
func (w *Walker) writeType(buf *bytes.Buffer, typ types.Type) {
switch typ := typ.(type) {
case *types.Basic:
@@ -763,9 +793,16 @@
case *types.Interface:
buf.WriteString("interface{")
- if typ.NumMethods() > 0 {
+ if typ.NumMethods() > 0 || typ.NumEmbeddeds() > 0 {
buf.WriteByte(' ')
+ }
+ if typ.NumMethods() > 0 {
buf.WriteString(strings.Join(sortedMethodNames(typ), ", "))
+ }
+ if typ.NumEmbeddeds() > 0 {
+ buf.WriteString(strings.Join(w.sortedEmbeddeds(typ), ", "))
+ }
+ if typ.NumMethods() > 0 || typ.NumEmbeddeds() > 0 {
buf.WriteByte(' ')
}
buf.WriteString("}")
@@ -800,12 +837,18 @@
}
buf.WriteString(typ.Obj().Name())
+ case *types.TypeParam:
+ buf.WriteString(typ.Obj().Name())
+
default:
panic(fmt.Sprintf("unknown type %T", typ))
}
}
func (w *Walker) writeSignature(buf *bytes.Buffer, sig *types.Signature) {
+ if tparams := sig.TypeParams(); tparams != nil {
+ w.writeTypeParams(buf, tparams, true)
+ }
w.writeParams(buf, sig.Params(), sig.Variadic())
switch res := sig.Results(); res.Len() {
case 0:
@@ -819,6 +862,23 @@
}
}
+func (w *Walker) writeTypeParams(buf *bytes.Buffer, tparams *types.TypeParamList, withConstraints bool) {
+ buf.WriteByte('[')
+ c := tparams.Len()
+ for i := 0; i < c; i++ {
+ if i > 0 {
+ buf.WriteString(", ")
+ }
+ tp := tparams.At(i)
+ buf.WriteString(tp.Obj().Name())
+ if withConstraints {
+ buf.WriteByte(' ')
+ w.writeType(buf, tp.Constraint())
+ }
+ }
+ buf.WriteByte(']')
+}
+
func (w *Walker) writeParams(buf *bytes.Buffer, t *types.Tuple, variadic bool) {
buf.WriteByte('(')
for i, n := 0, t.Len(); i < n; i++ {
@@ -872,6 +932,12 @@
func (w *Walker) emitType(obj *types.TypeName) {
name := obj.Name()
+ if tparams := obj.Type().(*types.Named).TypeParams(); tparams != nil {
+ var buf bytes.Buffer
+ buf.WriteString(name)
+ w.writeTypeParams(&buf, tparams, true)
+ name = buf.String()
+ }
typ := obj.Type()
if obj.IsAlias() {
w.emitf("type %s = %s", name, w.typeString(typ))
@@ -995,7 +1061,13 @@
log.Fatalf("exported method with unexported receiver base type: %s", m)
}
}
- w.emitf("method (%s) %s%s", w.typeString(recv), m.Obj().Name(), w.signatureString(sig))
+ tps := ""
+ if rtp := sig.RecvTypeParams(); rtp != nil {
+ var buf bytes.Buffer
+ w.writeTypeParams(&buf, rtp, false)
+ tps = buf.String()
+ }
+ w.emitf("method (%s%s) %s%s", w.typeString(recv), tps, m.Obj().Name(), w.signatureString(sig))
}
func (w *Walker) emitf(format string, args ...interface{}) {
diff --git a/src/cmd/api/testdata/src/pkg/p4/golden.txt b/src/cmd/api/testdata/src/pkg/p4/golden.txt
new file mode 100644
index 0000000..d5f282b
--- /dev/null
+++ b/src/cmd/api/testdata/src/pkg/p4/golden.txt
@@ -0,0 +1,4 @@
+pkg p4, func NewPair[T1 interface{ M }, T2 interface{ ~int }](T1, T2) Pair
+pkg p4, method (Pair[_, X2]) Second() X2
+pkg p4, method (Pair[X1, _]) First() X1
+pkg p4, type Pair[T1 interface{ M }, T2 interface{ ~int }] struct
diff --git a/src/cmd/api/testdata/src/pkg/p4/p4.go b/src/cmd/api/testdata/src/pkg/p4/p4.go
new file mode 100644
index 0000000..187339b
--- /dev/null
+++ b/src/cmd/api/testdata/src/pkg/p4/p4.go
@@ -0,0 +1,22 @@
+// 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.
+
+package p4
+
+type Pair[T1 interface { M() }, T2 ~int] struct {
+ f1 T1
+ f2 T2
+}
+
+func NewPair[T1 interface { M() }, T2 ~int](v1 T1, v2 T2) Pair[T1, T2] {
+ return Pair[T1, T2]{f1: v1, f2: v2}
+}
+
+func (p Pair[X1, _]) First() X1 {
+ return p.f1
+}
+
+func (p Pair[_, X2]) Second() X2 {
+ return p.f2
+}
