Post-audit field test of the operator-routing-eq-ord milestone
(closed via 5170b6a + 4d45bc6). Five `.ail` Surface-form fixtures
under `examples/fieldtest/` written by an LLM-author working
strictly from the design/ ledger + public examples (no
`crates/` / `runtime/` / `bench/` reads — Iron Law honoured):
eqord_1_fizzbuzz.ail — FizzBuzz [1..15] via (app eq …)
on Int+Str and (app gt …) on Int
eqord_2_rational_eq.ail — data Rational + user-instance
(class prelude.Eq) by cross-mult;
inner Int-eq nested in instance body
eqord_3_newton_sqrt.ail — Newton's method via float_lt
(convergence + fabs) and float_eq
(zero-guard)
eqord_4_float_ord_must_fail.ail — (app lt 1.5 2.5) must reject
at typecheck with float_lt hint
eqord_5_float_eq_must_fail.ail — (app eq 1.5 1.5) must reject
at typecheck with float_eq hint
Findings:
[working] x4 — primitive Eq/Ord at Int/Bool/Str/Unit;
user-ADT Eq with nested primitive eq calls; Float named-fn
surface (float_eq/float_lt/etc.); NoInstance Eq/Ord Float
diagnostic with float_eq / float_lt addendum. The milestone's
central thesis (class-dispatch is the only comparison
surface; Float opts out via named fns) is LLM-natural —
every (app eq …) / (app gt …) / (app float_lt …) call I
wrote compiled on first try with no diagnostic friction.
[spec_gap] x1 — `docs/specs/2026-05-20-operator-routing-eq-ord.md:113`
north-star example writes bare `(class Eq)` where the
language requires `(class prelude.Eq)`. An LLM-author who
copies the spec verbatim hits `bare-cross-module-class-ref`.
The milestone spec is the highest-information reference an
LLM-author consults; the bare-vs-qualified drift mis-primes
the pattern. Resolution: tighten-the-design-ledger — fix
the spec example inline (separate follow-up commit). The
existing `examples/eq_ord_user_adt.ail` already uses the
qualified form, so the corpus is consistent; only the spec
drifted.
[friction] x1 — `(app compare 1.5 2.5)` at Float fires the
same diagnostic as `(app lt …)` at Float, naming
`float_eq / float_lt (and siblings)` as the alternative.
But the alternatives don't return Ordering; an LLM-author
who wanted three-way LT/EQ/GT can't satisfy that with
float_lt + float_eq alone. The spec (lines 433-436)
acknowledged this case in commentary — "no float_compare
ships; build it from float_lt + float_eq if you need
three-way" — but the diagnostic doesn't say so. Resolution:
file as Gitea backlog issue for a follow-up tidy iteration
(codegen-side: branch the Float-aware NoInstance addendum
on the called method-name; the `compare` arm gets a
one-sentence "no float_compare; build it from float_lt +
float_eq if you need three-way" addendum).
Status: clean — no bugs, no blockers, the milestone surface is
solidly LLM-usable. Both non-working findings are tractable
forward-fixes that don't disturb the milestone's core
contracts.
Spec: docs/specs/2026-05-21-fieldtest-operator-routing-eq-ord.md
