diff --git a/current/CHECKPOINT-METATYPE.md b/current/CHECKPOINT-METATYPE.md index 5743c72f..b08a450a 100644 --- a/current/CHECKPOINT-METATYPE.md +++ b/current/CHECKPOINT-METATYPE.md @@ -4,6 +4,31 @@ Companion to [PLAN-METATYPE.md](PLAN-METATYPE.md). Update after every step (one step at a time, per the cadence rule). ## Last completed step +**`type_info($T)` reflection — enum round-trip.** Reflect a type INTO a `TypeInfo` +value (the inverse of `define`'s decode), so `define(declare(n), type_info(T))` +mints a byte-identical copy with NO literal variant list. + +- `inst.zig`: new `BuiltinId.type_info` (comptime-only, alongside `declare`/`define`). +- `lower/call.zig:tryLowerReflectionCall`: the old "not yet implemented" bail is + gone. Resolve `$T` at lower time, reject a non-`enum`/non-`tagged_union` arg + loudly (good span: `"type_info: 'X' is not an enum …"`), else emit + `callBuiltin(.type_info, [const_type], TypeInfo)`. +- `interp.zig:reflectTypeInfo`: builds the exact nested-aggregate Value + `defineEnum` decodes — variant `{name, payload}`, slice `{data, len}`, EnumInfo + `{variants}`, TypeInfo `{tag0, EnumInfo}`. A `tagged_union` reflects each + `field.ty` (tagless variants already carry `void`); a payloadless `` `enum `` + reflects `void` per variant. Round-trips both source enums AND constructed + (declare/define) enums. +- emit unchanged — `type_info` is always comptime-evaluated; the existing + comptime-only `else` arm in `emitCallBuiltin` (shared with declare/define) + never fires. +- Scope: **enum-only** (the symmetric inverse of `define`'s current capability). + Struct/tuple `TypeInfo` widening is a separate later step. + +`examples/0619` locks it (source enum `circle:f64 / rect:i64 / empty` reflected → +reconstructed → constructs + matches). Full suite green (676 examples + units). + +## Prior step **Self-reference — recursive enums via `declare("Name")` + `*Name`.** The `declare`/`define` floor now supports self-referential types. @@ -39,7 +64,9 @@ traversal)**; `field_type` reflection `0616`. Full suite green (674 examples). (reflection). No constructor-name knowledge anywhere in the compiler — every named constructor is sx. `declare(name)` carries the type name (compile-time string) for forward-type registration. -- `type_info` still bails loudly (`call.zig:tryLowerReflectionCall`) — pending. +- `type_info($T)` reflects an `enum`/`tagged_union` INTO a `TypeInfo` value + (`call.zig` emits `callBuiltin(.type_info)`; `interp.zig:reflectTypeInfo` builds + the Value). Enum-only; struct/tuple widening pending. `examples/0619` round-trip. ## Decision (kept) **Meta lives in `modules/std/meta.sx`, not the prelude.** Declaring its data types @@ -51,10 +78,10 @@ Pick any (independent): - **`make_enum(variants: []EnumVariant)`** sx helper over a COMPUTED (non-literal) variant list — exercises the interpreter decoding a value-arg slice in `define` (vs. the literal `.[ … ]` the current examples use). -- **`type_info($T) -> TypeInfo`** — reflect a type INTO a value (inverse of - `define`'s decode); widen `TypeInfo` past `` `enum `` + construct a - `[]EnumVariant` value in the interp. Bails loudly today in - `call.zig:tryLowerReflectionCall`. Its own focused effort. +- **Widen `type_info` / `TypeInfo` past `` `enum ``** — struct/tuple variants: + add `` .`struct ``/`` .`tuple `` to the `TypeInfo` enum in `meta.sx`, teach + `reflectTypeInfo` to build them, and teach `defineEnum` (→ a `defineType`) to + decode them. Round-trips a struct through `define` once it lands. - **Validation + loud diagnostics** (remaining) — duplicate variant names, a `declare()` never `define()`d (hard error), use-before-define. (By-value self-reference already rejected — issue 0139.) @@ -65,6 +92,13 @@ Pass 1g emits a loud "infinitely sized" diagnostic + breaks the cycle; covers source + comptime types; `examples/1178` locks it.) ## Log +- **`type_info($T)` reflection done (enum round-trip).** New `BuiltinId.type_info`; + `lower/call.zig` resolves `$T`, rejects non-enum loudly, emits the builtin; + `interp.zig:reflectTypeInfo` constructs the exact nested-aggregate Value + `defineEnum` decodes (variant `{name,payload}` / slice `{data,len}` / EnumInfo / + TypeInfo `.enum`). `tagged_union` reflects `field.ty`; payloadless `` `enum `` + reflects `void`. Round-trips source AND constructed enums. Enum-only; + struct/tuple widening deferred. `examples/0619` locks it. Suite green (676). - **By-value self-reference rejected (issue 0139, F5 partial).** New `checkInfiniteSize` pass (Pass 1g) detects by-VALUE containment cycles (source + comptime types, direct + mutual), emits a loud "infinitely sized" diagnostic, diff --git a/current/PLAN-METATYPE.md b/current/PLAN-METATYPE.md index 17cf62a6..4c36fd93 100644 --- a/current/PLAN-METATYPE.md +++ b/current/PLAN-METATYPE.md @@ -10,7 +10,8 @@ Comptime type metaprogramming with the smallest possible compiler surface: - **`define(handle, info) -> Type`** — fill a declared handle's body from a `TypeInfo` *value*, and return the handle (so the one-shot form chains). - **`type_info($T) -> TypeInfo`** — reflect a type INTO data (the inverse of - `define`'s decode). *Pending.* + `define`'s decode). *Done for enums* (`interp.zig:reflectTypeInfo`, + `examples/0619`); struct/tuple widening pending. - **`field_type($T, i) -> Type`** — the i-th field / variant-payload / element type of `$T`. *Done.* @@ -109,10 +110,12 @@ while red. Examples: `06xx` (comptime), `11xx` (diagnostics). - [ ] **`make_enum(variants: []EnumVariant)`** sx helper over a COMPUTED (non-literal) variant list — exercises the interpreter decoding a value-arg slice in `define`. -- [ ] **`type_info($T) -> TypeInfo`** — reflect a type INTO a value (inverse of - `define`'s decode): widen `TypeInfo` past `` `enum `` (struct/tuple) AND - construct a `[]EnumVariant`-style value in the interpreter. Bails loudly today - in `call.zig:tryLowerReflectionCall`. Round-trips through `define` once it lands. +- [x] **`type_info($T) -> TypeInfo`** (enum-only) — reflect an `enum`/`tagged_union` + INTO a value (inverse of `define`'s decode): `interp.zig:reflectTypeInfo` + constructs the `.enum(EnumInfo{ variants })` Value `defineEnum` decodes, so + `define(declare(n), type_info(T))` round-trips. `examples/0619`. Non-enum args + rejected loudly at lower time. **Still pending:** widen `TypeInfo` past + `` `enum `` (struct/tuple variants) + the matching `define` decode arms. - [~] **Validation + loud diagnostics** — by-VALUE self-reference DONE (`checkInfiniteSize` Pass 1g: loud "infinitely sized" diagnostic + cycle break, covers source + comptime types; `examples/1178`, issue 0139 resolved).