func (k <type 28>) String () <type -16>;
>; Implements (u <type 26>) <type -15>; AssignableTo (u <type 26>) <type -15>; Bits () <type -11>; ChanDir () <type 29 "ChanDir" <type -11>
 func (d <type 29>) String () <type -16>;

func (t *Type) Common() *Type {
	return t
}

type ChanDir int

const (
	RecvDir    ChanDir = 1 << iota         // <-chan
	SendDir                                // chan<-
	BothDir            = RecvDir | SendDir // chan
	InvalidDir ChanDir = 0
)

// ChanType represents a channel type
type ChanType struct {
	Type
	Elem *Type
	Dir  ChanDir
}

type structTypeUncommon struct {
	StructType

		// x is a bidirectional channel value, T is a channel type,
		// and x's type V and T have identical element types.
		if V.ChanDir() == abi.BothDir && haveIdenticalType(T.Elem(), V.Elem(), cmpTags) {
			return true
		}

		// Otherwise continue test for identical underlying type.
		return V.ChanDir() == T.ChanDir() && haveIdenticalType(T.Elem(), V.Elem(), cmpTags)

	case abi.Func:
		t := (*funcType)(unsafe.Pointer(T))

	case TCHAN:
		switch t.ChanDir() {
		case Crecv:
			b.WriteString("<-chan ")
			tconv2(b, t.Elem(), 0, mode, visited)
		case Csend:
			b.WriteString("chan<- ")
			tconv2(b, t.Elem(), 0, mode, visited)
		default:
			b.WriteString("chan ")
			if t.Elem() != nil && t.Elem().IsChan() && t.Elem().Sym() == nil && t.Elem().ChanDir() == Crecv {
				b.WriteByte('(')

pkg go/types, const MethodVal SelectionKind
pkg go/types, const RecvOnly = 2
pkg go/types, const RecvOnly ChanDir
pkg go/types, const Rune = 5
pkg go/types, const Rune BasicKind
pkg go/types, const SendOnly = 1
pkg go/types, const SendOnly ChanDir
pkg go/types, const SendRecv = 0
pkg go/types, const SendRecv ChanDir
pkg go/types, const String = 17
pkg go/types, const String BasicKind
pkg go/types, const Uint = 7

		Colon token.Pos // position of ":"
		Value Expr
	}
)

// The direction of a channel type is indicated by a bit
// mask including one or both of the following constants.
type ChanDir int

const (
	SEND ChanDir = 1 << iota
	RECV
)

// A type is represented by a tree consisting of one
// or more of the following type-specific expression
// nodes.
type (

		value := TypeExpr(f, pkg, t.Elem())
		if key == nil || value == nil {
			return nil
		}
		return &ast.MapType{
			Key:   key,
			Value: value,
		}
	case *types.Chan:
		dir := ast.ChanDir(t.Dir())
		if t.Dir() == types.SendRecv {
			dir = ast.SEND | ast.RECV
		}
		value := TypeExpr(f, pkg, t.Elem())
		if value == nil {
			return nil
		}
		return &ast.ChanType{
			Dir:   dir,

	n.Chan = DefaultLit(n.Chan, nil)
	t := n.Chan.Type()
	if t == nil {
		return n
	}
	if !t.IsChan() {
		base.Errorf("invalid operation: %v (send to non-chan type %v)", n, t)
		return n
	}

	if !t.ChanDir().CanSend() {
		base.Errorf("invalid operation: %v (send to receive-only type %v)", n, t)
		return n
	}

	n.Value = AssignConv(n.Value, t.Elem(), "send")
	if n.Value.Type() == nil {
		return n
	}

		return types.NewPointer(r.typ())
	case sliceType:
		return types.NewSlice(r.typ())
	case arrayType:
		n := r.uint64()
		return types.NewArray(r.typ(), int64(n))
	case chanType:
		dir := chanDir(int(r.uint64()))
		return types.NewChan(dir, r.typ())
	case mapType:
		return types.NewMap(r.typ(), r.typ())
	case signatureType:
		r.currPkg = r.pkg()
		return r.signature(nil, nil, nil)

	case pkgbits.TypeTypeParam:
		return r.dict.tparams[r.Len()]

	case pkgbits.TypeArray:
		len := int64(r.Uint64())
		return types.NewArray(r.typ(), len)
	case pkgbits.TypeChan:
		dir := types.ChanDir(r.Len())
		return types.NewChan(dir, r.typ())
	case pkgbits.TypeMap:
		return types.NewMap(r.typ(), r.typ())
	case pkgbits.TypePointer:
		return types.NewPointer(r.typ())
	case pkgbits.TypeSignature: