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[dev.typeparams] go/types: update TypeParam APIs to match types2

This is a partial port of CL 323029, consisting only of changes to
go/types. Changes to the importer will be made in a separate CL.

Change-Id: I3b300f5e8f4df36c2c87e3f164705cd3c36218ac
Reviewed-on: https://go-review.googlesource.com/c/go/+/335145
Trust: Robert Findley <rfindley@google.com>
Run-TryBot: Robert Findley <rfindley@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>
This commit is contained in:
Rob Findley 2021-07-16 19:01:16 -04:00 committed by Robert Findley
parent 22a38ba5ca
commit 9e147c55b7
4 changed files with 22 additions and 19 deletions

View File

@ -783,9 +783,11 @@ func (check *Checker) applyTypeFunc(f func(Type) Type, x Type) Type {
return nil
}
// construct a suitable new type parameter
tpar := NewTypeName(token.NoPos, nil /* = Universe pkg */, "<type parameter>", nil)
ptyp := check.newTypeParam(tpar, 0, &emptyInterface) // assigns type to tpar as a side-effect
// Construct a suitable new type parameter for the sum type. The
// type param is placed in the current package so export/import
// works as expected.
tpar := NewTypeName(token.NoPos, check.pkg, "<type parameter>", nil)
ptyp := check.NewTypeParam(tpar, 0, &emptyInterface) // assigns type to tpar as a side-effect
tsum := newUnion(rtypes, tildes)
ptyp.bound = &Interface{complete: true, tset: &TypeSet{types: tsum}}

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@ -758,7 +758,7 @@ func (check *Checker) collectTypeParams(list *ast.FieldList) []*TypeName {
func (check *Checker) declareTypeParams(tparams []*TypeName, names []*ast.Ident) []*TypeName {
for _, name := range names {
tpar := NewTypeName(name.Pos(), check.pkg, name.Name, nil)
check.newTypeParam(tpar, len(tparams), &emptyInterface) // assigns type to tpar as a side-effect
check.NewTypeParam(tpar, len(tparams), &emptyInterface) // assigns type to tpar as a side-effect
check.declare(check.scope, name, tpar, check.scope.pos) // TODO(gri) check scope position
tparams = append(tparams, tpar)
}

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@ -41,11 +41,13 @@ func under(t Type) Type {
return t
}
// optype returns a type's operational type. Except for type parameters,
// the operational type is the same as the underlying type (as returned
// by under). For Type parameters, the operational type is determined
// by the corresponding type constraint. The result may be the top type,
// but it is never the incoming type parameter.
// optype returns a type's operational type. Except for
// type parameters, the operational type is the same
// as the underlying type (as returned by under). For
// Type parameters, the operational type is determined
// by the corresponding type bound's type list. The
// result may be the bottom or top type, but it is never
// the incoming type parameter.
func optype(typ Type) Type {
if t := asTypeParam(typ); t != nil {
// If the optype is typ, return the top type as we have

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@ -27,22 +27,14 @@ type TypeParam struct {
bound Type // *Named or *Interface; underlying type is always *Interface
}
// NewTypeParam returns a new TypeParam.
func NewTypeParam(obj *TypeName, index int, bound Type) *TypeParam {
return (*Checker)(nil).newTypeParam(obj, index, bound)
}
// TODO(rfindley): this is factored slightly differently in types2.
func (check *Checker) newTypeParam(obj *TypeName, index int, bound Type) *TypeParam {
assert(bound != nil)
// NewTypeParam returns a new TypeParam. bound can be nil (and set later).
func (check *Checker) NewTypeParam(obj *TypeName, index int, bound Type) *TypeParam {
// Always increment lastID, even if it is not used.
id := nextID()
if check != nil {
check.nextID++
id = check.nextID
}
typ := &TypeParam{check: check, id: id, obj: obj, index: index, bound: bound}
if obj.typ == nil {
obj.typ = typ
@ -79,6 +71,13 @@ func (t *TypeParam) Bound() *Interface {
return iface
}
func (t *TypeParam) _SetBound(bound Type) {
if bound == nil {
panic("internal error: bound must not be nil")
}
t.bound = bound
}
func (t *TypeParam) Underlying() Type { return t }
func (t *TypeParam) String() string { return TypeString(t, nil) }