fn plan_subscript(
ecx: &ExprContext<'_>,
expr: &Expr<Aug>,
positions: &[SubscriptPosition<Aug>],
) -> Result<CoercibleScalarExpr, PlanError>
fn plan_subscript(
ecx: &ExprContext<'_>,
expr: &Expr<Aug>,
positions: &[SubscriptPosition<Aug>],
) -> Result<CoercibleScalarExpr, PlanError>