Positional binding-reorder mutants for every standalone/pipe query macro that takes a binding pattern list — the where/having condition macros, select, select_merge, order_by, group_by, distinct, join, preload, windows, …, and the free-standing dynamic/2 (the condition/clause/join/dynamic descriptors in Mutare.Ecto.Surface).

A binding list maps names to the query's bindings by position: [a, b] binds a→1st, b→2nd. Transposing two positional entries ([a, b] → [b, a]) asks whether their order matters. Named bindings (comments: c) are addressed by name, not position, so they are left in place. _-prefixed bindings are intentionally ignored, matching core's pattern-swap policy.

The reorder is always delivered in place — by swapping the written list, never by rewriting the condition body. The list sits in an ordinary argument position (not inside a macro-expanded query fragment), so the whole macro call (itself an expression returning a query) rides Mutare's ordinary selector case; no host / dynamic weaving is needed. Leaving the body byte-for-byte untouched is also what makes the swap safe across an opaque author macro in that body (the author-macro rule — see Mutare.Ecto.Walk). Wrong-schema field access from a swap surfaces at query-plan time (runtime), not compile time, so a mutant never poisons the single build.

This covers the macros whose binding list is an argument. A from's binding-list source (from [a, b] in q, …) is written at the whole-from level, so its reorder is delivered there (Mutare.Ecto.Query) — one whole-from mutant swapping the source declaration, never a per-clause rewrite. A scalar from source (u in User) and the join-introduced bindings are synthesized, not written as a list, so they never reorder.

Every pair of eligible bindings is swapped, even when one or both are unused. Such a surviving mutant identifies a redundant binding declaration, matching core's pattern-swap policy.