}

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

	fun := astutil.Unparen(call.Fun)

	// Look through type instantiation if necessary.
	isInstance := false
	switch fun.(type) {
	case *ast.IndexExpr, *ast.IndexListExpr:
		// When extracting the callee from an *IndexExpr, we need to check that
		// it is a *types.Func and not a *types.Var.
		// Example: Don't match a slice m within the expression `m[0]()`.
		isInstance = true

	"go/internal/typeparams"
	. "internal/types/errors"
)

// If e is a valid function instantiation, indexExpr returns true.
// In that case x represents the uninstantiated function value and
// it is the caller's responsibility to instantiate the function.
func (check *Checker) indexExpr(x *operand, e *typeparams.IndexExpr) (isFuncInst bool) {
	check.exprOrType(x, e.X, true)
	// x may be generic

	switch x.mode {
	case invalid:

	//    in the source.
	// 2) The position of a node representing a non-terminal production
	//    (IndexExpr, IfStmt, etc.) is the position of a token uniquely
	//    associated with that production; usually the left-most one
	//    ('[' for IndexExpr, 'if' for IfStmt, etc.)
	Pos() Pos
	SetPos(Pos)
	aNode()
}

type node struct {
	// commented out for now since not yet used

	return inst
}

func (check *Checker) callExpr(x *operand, call *syntax.CallExpr) exprKind {
	var inst *syntax.IndexExpr // function instantiation, if any
	if iexpr, _ := call.Fun.(*syntax.IndexExpr); iexpr != nil {
		if check.indexExpr(x, iexpr) {
			// Delay function instantiation to argument checking,
			// where we combine type and value arguments for type
			// inference.

	"go/constant"
	. "internal/types/errors"
)

// If e is a valid function instantiation, indexExpr returns true.
// In that case x represents the uninstantiated function value and
// it is the caller's responsibility to instantiate the function.
func (check *Checker) indexExpr(x *operand, e *syntax.IndexExpr) (isFuncInst bool) {
	check.exprOrType(x, e.X, true)
	// x may be generic

	switch x.mode {
	case invalid:

	}
	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
	}
}

					},
				})
			}
		}
	})

	return nil, nil
}

// isMapIndex returns true if e is a map index expression.
func isMapIndex(info *types.Info, e ast.Expr) bool {
	if idx, ok := astutil.Unparen(e).(*ast.IndexExpr); ok {
		if typ := info.Types[idx.X].Type; typ != nil {
			_, ok := typ.Underlying().(*types.Map)
			return ok
		}
	}
	return false

			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 {