Brummel
625fe849be
First tranche of a contracts-against-code audit (the inverse of the
usual direction: testing the ledger's claims against the code). Each
fix here is a verified factual divergence between a contract and the
code; the direction of the fix follows which side actually drifted.
Code drifted from the stated goal -> fix the code:
- 0014's claim 6 ("`cargo doc --no-deps` runs warning-free") was the
design goal; reality had 6 warnings. Demote the offending intra-doc
links to plain code spans so the docs match the goal:
- ailang-core: `[`load_workspace`]` cannot resolve from core (the
fn lives in ailang-surface, which core may not depend on) — three
sites in workspace.rs.
- ailang-check: three public-item docs linked the `pub(crate)`
helpers `qualify_local_types` / `qualify_workspace_types`.
`cargo doc --no-deps --workspace` is now warning-free.
Contract stale, code legitimately advanced -> fix the contract:
- 0011 stated `float_to_str` "codegen is reserved and not yet
shipped". It is shipped: lowers to `@ailang_float_to_str(double)`,
green under the codegen `float_to_str_no_longer_errors_internal`
unit test and the e2e `float_to_str_smoke`. The docs_honesty_pin
anchor that protected the stale "reserved" wording moved in lockstep
to assert the present-tense lowering instead — the pin had been
guarding a claim the code already falsified.
- 0013 named the diagnostic `ConstraintReferencesUnboundTypeVar`; the
variant is `UnboundConstraintTypeVar` (workspace.rs), and its scope
is a class-method signature whose constraint mentions a tyvar bound
neither by the method's `forall` nor by the class `param`.
- 0017 called the primitive Eq/Ord bodies "placeholder lambdas"; they
carry the `(intrinsic)` marker — the lockstep partner to the
INTERCEPTS registry, not a placeholder.
- 0009 said "seven" `.ail.json` carve-outs and described the inventory
test as pinning seven; the test pins twelve (7 subject-matter + 4
recur + 1 loop-binder, per carve_out_inventory.rs).
Verified separately: 0001's "pretty-printer code in pretty.rs was
deleted, leaving only diagnostic helpers" is factually correct (an
audit agent misread it as "pretty.rs was deleted"); its only issue is
history phrasing, deferred to the honesty-prose tranche.
Deferred to later tranches: honesty-rule prose (history/rationale that
is not a protected honest-reserved/tiebreaker anchor), stale/mislinked
ratifying-tests (0014's `architect_sweeps.sh`, 0015's uniqueness
in-source tests), 0014's never-existent `tests/expected/`, 0012's
non-exhaustive tail-context list, and the 0016<->0013 redundancy.
75 lines
4.0 KiB
Markdown
75 lines
4.0 KiB
Markdown
# Prelude (built-in) classes
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## Prelude (built-in) classes
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The prelude ships the `Ordering` ADT, the `Eq` and `Ord`
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[classes](0013-typeclasses.md), primitive `Eq Int/Bool/Str/Unit` and
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`Ord Int/Bool/Str` instances, and the five polymorphic free-fn
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helpers `ne`/`lt`/`le`/`gt`/`ge`. The primitive `Eq` / `Ord`
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instance bodies carry the `(intrinsic)` marker in `examples/prelude.ail`
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(the marker is the lockstep partner to the `INTERCEPTS` registry);
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the codegen intercept `try_emit_primitive_instance_body` supplies
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their single-instruction bodies (`icmp eq i64` for `eq__Int`,
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`icmp eq i1` for `eq__Bool`, `@ail_str_eq` for `eq__Str`,
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`ret i1 1` for `eq__Unit`; a three-way `icmp` ladder constructing
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`LT`/`EQ`/`GT` for `compare__T`) and attaches `alwaysinline` so
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the call folds to the single instruction at every use site.
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The five Ord-class free helpers (`ne`/`lt`/`le`/`gt`/`ge`) have
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source-level bodies that route through `eq` / `compare` plus
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`match` over `Ordering` — written that way so the surface form is
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LLM-natural and so user-ADT instances of `Eq`/`Ord` automatically
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pick up working helpers without any per-type opt-in. At Int the
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codegen intercept short-circuits this indirection: `lt__Int`,
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`le__Int`, `gt__Int`, `ge__Int`, and `ne__Int` are intercept-
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overridden to emit `icmp slt i64` / `sle i64` / `sgt i64` /
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`sge i64` / `ne i64` directly, bypassing the `compare__Int` →
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`Ordering`-ctor → `match` path. Without this short-circuit the
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`Ordering` ctor allocates per call inside hot loops — a real
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cost surfaced by the `bench_closure_chain` regression at the
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operator-routing-eq-ord milestone and pinned by
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`crates/ail/tests/ord_int_intercept_ir_pin.rs`. The short-circuit
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is *Int-only* by deliberate asymmetry: no current bench or
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example fixture exercises Ord-`lt`/`le`/`gt`/`ge` at Bool or
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Str at sufficient call frequency to justify the intercept-arm
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maintenance; the symmetric extensions are mechanical when the
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first such workload appears.
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Float has neither `Eq` nor `Ord` instance per [Float semantics](
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0005-float-semantics.md); a polymorphic helper invoked at Float fires
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`NoInstance` at typecheck with a Float-aware diagnostic that names
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the explicit `float_eq` / `float_lt` alternatives and
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cross-references this section. The lookup machinery that turns a
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`show x` call site into the right monomorphic instance is
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documented in [method dispatch](0016-method-dispatch.md).
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Float comparison is a separate surface: the six monomorphic prelude
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fns `float_eq` / `float_ne` / `float_lt` / `float_le` / `float_gt`
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/ `float_ge` each carry the type `(Float, Float) -> Bool` without
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a class constraint. They lower via the same intercept machinery as
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the primitive `Eq` instances (single `fcmp` instruction with the
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matching predicate `oeq` / `une` / `olt` / `ole` / `ogt` / `oge`,
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plus `alwaysinline`). They replace what would otherwise be a
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polymorphic `==` / `<` on Float — Float gets full comparability
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via explicit named fns, not via an implicit class instance.
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The prelude ships `class Show a where show : (a borrow) -> Str` and
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primitive `Show Int`, `Show Bool`, `Show Str`, `Show Float`
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instances. Float **is** included in Show (unlike Eq/Ord) — IEEE-754
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makes structural equality and total ordering semantically dubious,
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but textual representation of a Float is well-defined modulo the
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NaN-spelling caveat in [Float semantics](0005-float-semantics.md). Each
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`Show <T>` instance body is a single-application lambda invoking the
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corresponding runtime primitive (`int_to_str`, `bool_to_str`,
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`str_clone`, `float_to_str`; see [Str ABI](0011-str-abi.md) for the
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heap-Str primitives); no codegen intercept is required. The
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polymorphic helper `print : forall a. Show a => a -> () !IO` has body
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`\x -> let s = show x in do io/print_str s` (explicit let-binder for
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heap-Str RC discipline per the Str carve-out in
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[Str ABI](0011-str-abi.md)). The let-binder is
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structurally pinned by `crates/ail/tests/print_mono_body_shape.rs`.
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Routing through `print` is the path for non-`Str` primitives;
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`io/print_str` is the only built-in direct-output effect-op.
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Ratified by: `crates/ail/tests/show_no_instance_e2e.rs`.
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