func PackIndexExpr(x ast.Expr, lbrack token.Pos, exprs []ast.Expr, rbrack token.Pos) ast.Expr
IndexExpr wraps an ast.IndexExpr or ast.IndexListExpr.
Orig holds the original ast.Expr from which this IndexExpr was derived.
type IndexExpr struct { Orig ast.Expr // the wrapped expr, which may be distinct from the IndexListExpr below. *ast.IndexListExpr }
func UnpackIndexExpr(n ast.Node) *IndexExpr