golang typelists 代码
文件路径：/src/cmd/compile/internal/types2/typelists.go
/ 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 types2
/ TypeParamList holds a list of type parameters.
type TypeParamList struct{ tparams []*TypeParam }
/ Len returns the number of type parameters in the list.
/ It is safe to call on a nil receiver.
func (l *TypeParamList) Len() int { return len(l.list()) }
/ At returns the i'th type parameter in the list.
func (l *TypeParamList) At(i int) *TypeParam { return l.tparams[i] }
/ list is for internal use where we expect a []*TypeParam.
/ TODO(rfindley): list should probably be eliminated: we can pass around a
/ TypeParamList instead.
func (l *TypeParamList) list() []*TypeParam {
if l == nil {
return nil
}
return l.tparams
}
/ TypeList holds a list of types.
type TypeList struct{ types []Type }
/ newTypeList returns a new TypeList with the types in list.
func newTypeList(list []Type) *TypeList {
if len(list) == 0 {
return nil
}
return &TypeList{list}
}
/ Len returns the number of types in the list.
/ It is safe to call on a nil receiver.
func (l *TypeList) Len() int { return len(l.list()) }
/ At returns the i'th type in the list.
func (l *TypeList) At(i int) Type { return l.types[i] }
/ list is for internal use where we expect a []Type.
/ TODO(rfindley): list should probably be eliminated: we can pass around a
/ TypeList instead.
func (l *TypeList) list() []Type {
if l == nil {
return nil
}
return l.types
}
/ ----------------------------------------------------------------------------
/ Implementation
func bindTParams(list []*TypeParam) *TypeParamList {
if len(list) == 0 {
return nil
}
for i, typ := range list {
if typ.index >= 0 {
panic("type parameter bound more than once")
}
typ.index = i
}
return &TypeParamList{tparams: list}
}