}

func (x *IndexExpr) Pos() token.Pos {
	return x.Orig.Pos()
}

func UnpackIndexExpr(n ast.Node) *IndexExpr {
	switch e := n.(type) {
	case *ast.IndexExpr:
		return &IndexExpr{
			Orig:    e,
			X:       e.X,
			Lbrack:  e.Lbrack,
			Indices: []ast.Expr{e.Index},
			Rbrack:  e.Rbrack,
		}
	case *ast.IndexListExpr:
		return &IndexExpr{
			Orig:    e,
			X:       e.X,

	switch e := n.(type) {
	case *ast.IndexExpr:
		return e.X, e.Lbrack, []ast.Expr{e.Index}, e.Rbrack
	case *ast.IndexListExpr:
		return e.X, e.Lbrack, e.Indices, e.Rbrack
	}
	return nil, token.NoPos, nil, token.NoPos
}

// PackIndexExpr returns an *ast.IndexExpr or *ast.IndexListExpr, depending on
// the cardinality of indices. Calling PackIndexExpr with len(indices) == 0

	}
	for _, n := range names {
		if f.Name() == n {
			return true
		}
	}
	return false
}

func funcIdent(fun ast.Expr) *ast.Ident {
	switch fun := astutil.Unparen(fun).(type) {
	case *ast.IndexExpr, *ast.IndexListExpr:
		x, _, _, _ := typeparams.UnpackIndexExpr(fun) // necessary?
		id, _ := x.(*ast.Ident)
		return id
	case *ast.Ident:
		return fun
	default:
		return nil
	}
}

			if n.Type != nil {
				m = n.Type
				continue
			}
			return n.Pos()
		case *KeyValueExpr:
			m = n.Key
		// case *FuncLit:
		// case *ParenExpr:
		case *SelectorExpr:
			m = n.X
		case *IndexExpr:
			m = n.X
		// case *SliceExpr:
		case *AssertExpr:
			m = n.X
		case *TypeSwitchGuard:
			if n.Lhs != nil {
				m = n.Lhs
				continue
			}
			m = n.X
		case *Operation:
			if n.Y != nil {

	case *ast.ParenExpr:
		buf.WriteByte('(')
		WriteExpr(buf, x.X)
		buf.WriteByte(')')

	case *ast.SelectorExpr:
		WriteExpr(buf, x.X)
		buf.WriteByte('.')
		buf.WriteString(x.Sel.Name)

	case *ast.IndexExpr, *ast.IndexListExpr:
		ix := typeparams.UnpackIndexExpr(x)
		WriteExpr(buf, ix.X)
		buf.WriteByte('[')
		writeExprList(buf, ix.Indices)
		buf.WriteByte(']')

	case *ast.SliceExpr:
		WriteExpr(buf, x.X)

			// *T is valid, but **T is not
			if op, _ := base.(*syntax.Operation); op == nil || ptrBase(op) == nil {
				return embeddedFieldIdent(e.X)
			}
		}
	case *syntax.SelectorExpr:
		return e.Sel
	case *syntax.IndexExpr:
		return embeddedFieldIdent(e.X)
	}
	return nil // invalid embedded field
}

func (check *Checker) declareInSet(oset *objset, pos syntax.Pos, obj Object) bool {
	if alt := oset.insert(obj); alt != nil {

		return e
	case *ast.StarExpr:
		// *T is valid, but **T is not
		if _, ok := e.X.(*ast.StarExpr); !ok {
			return embeddedFieldIdent(e.X)
		}
	case *ast.SelectorExpr:
		return e.Sel
	case *ast.IndexExpr:
		return embeddedFieldIdent(e.X)
	case *ast.IndexListExpr:
		return embeddedFieldIdent(e.X)
	}
	return nil // invalid embedded field
}

	case *CompositeLit:
		if n.Type != nil {
			Walk(v, n.Type)
		}
		walkList(v, n.Elts)

	case *ParenExpr:
		Walk(v, n.X)

	case *SelectorExpr:
		Walk(v, n.X)
		Walk(v, n.Sel)

	case *IndexExpr:
		Walk(v, n.X)
		Walk(v, n.Index)

	case *IndexListExpr:
		Walk(v, n.X)
		walkList(v, n.Indices)

	case *SliceExpr:
		Walk(v, n.X)
		if n.Low != nil {
			Walk(v, n.Low)
		}