pub type ExprPlan = (usize, Vec<Option<Rc<GroupMap>>>, Expr);Expand description
v7.29 (3c) - per-expression resolution plan: for the i-th scalar subquery node (pre-order) of a host expression, the shared batch map (None = unbatchable, resolve per row). Keyed by the HOST expression’s address - callers guarantee the expression outlives the per-query memo (aggregate items / WHERE trees do). The stored subquery count guards against address reuse. (subquery count, per-subquery batch maps, hollow template). The template is the host expression with every scalar subquery BODY emptied - cloning it per row costs nodes, not whole subquery ASTs (the splice walk replaces the hollow nodes by pre-order).