Design decision: a protocol-constrained pack element is viewed THROUGH the
constraint protocol — only the protocol's interface (its methods, and the
projections xs.T / xs.value) is accessible, not arbitrary concrete members,
exactly like a constrained generic `T: Show`. So `xs[i].v` (a field on the
concrete IntBox, not declared on Show) is an error; the constraint is enforced
and bounds the body regardless of the concrete arg types at a call site.
The previous example 191 demonstrated `xs[i].v` — which only compiled because
the constraint is not yet enforced. Trimmed it to the protocol-agnostic part
that's correct today (per-shape binding + comptime `xs.len` across arities /
heterogeneous shapes); protocol-interface access + projection are the remaining
2.4 work. specs.md records the access rule.
`..xs: Protocol` now binds like the comptime `..$args` pack instead of
falling through to a runtime `[]Protocol` slice: each call site
monomorphizes with the concrete per-position arg types, and `xs[i]` is the
concrete element via AST substitution (Decision 1 — a pack is a comptime
mechanism, no runtime pack value). So `xs[i]`'s own fields/methods dispatch
statically and elements may be heterogeneous, while `xs.len` is a comptime
constant.
Mechanism: one `isPackParam(p) = is_variadic and (is_comptime or is_pack)`
predicate replaces the four `is_variadic and is_comptime` pack-detection
sites (call-arg split, mangle, arg lowering, monomorphizePackFn), and the
early call dispatch routes any `isPackFn` call to `lowerPackFnCall` before
the `hasComptimeParams` gate (which is false for a protocol pack).
examples/191-protocol-pack.sx exercises N=0, N=2, concrete field access, and
a heterogeneous IntBox+StrBox pack. Conformance checking and projection
(`xs.T` / `xs.value`) are the remaining 2.4 work.
Add the name-resolution primitives a `..pack.<name>` projection needs
(Decision 4). A protocol exposes two namespaces: type-args (the
`protocol($T, ...)` params) and runtime accessors (its methods — protocols
have no fields). Resolution is position-driven with no cross-namespace
fallback:
- lookupProtocolArg(protocol, name) -> ?u32 (type_params index)
- lookupProtocolField(protocol, name) -> ?u32 (methods index)
- resolvePackProjection(protocol, name, pos) (.type_arg | .method | .not_found)
registerProtocolDecl now warns when a type-arg and a method share a name
(allowed, but `..pack.<name>` then resolves by position, which surprises
readers). 3 unit tests cover both namespaces, the position rule, and the
shadowing warning + deterministic resolution despite a shadow.
Projecting a *bound* pack (producing a new Pack of per-element results) waits
for call-site binding in Step 2.4; these primitives are what it will call
per element.
root.zig had no `test` block, so the test binary discovered zero tests and
trivially "passed" — every src test had silently rotted. Add
`refAllDecls(@This())` to root.zig so all 185 tests run, then fix the rot it
surfaced:
- emit_llvm.test: operands were constants, so LLVM folded the very
instructions being asserted (fadd/sub/icmp/insertvalue/extractvalue/sext).
Rewrite to use function-parameter operands; `main` now returns i32 (entry
convention); tagged-union enum_init lowers via memory, not insertvalue.
- interp.test: switch the per-test allocator to an arena (the interpreter is
arena-style and intentionally frees little) — clears the transient-Value
leaks without an ownership-ambiguous source change.
- lower.test: pass `is_imported` to lowerFunction; mark two helpers `pub`; the
if/else block test now uses a runtime (param) condition since lowering folds
`if true`.
- print.test: SSA numbering — params occupy %0/%1, so consts start at %2.
- jni_java_emit.test: nested-class refs render in Java source form
(`SurfaceHolder.Callback`), not the JNI `$` form.
Leaks fixed at the source where ownership was clear: Module gains an arena for
the operand slices the Builder dupes (struct/call/branch/switch args, block
params, lowerFunction params); objcDefinedStateStructType builds its field
slice in that arena and frees its temp name string.
Add a `pack` variant to IR `TypeInfo` — an ordered, interned sequence of
per-position element types (`PackInfo { elements: []const TypeId }`) — with
constructor (`packType`), structural equality + hashing, and a `pack(T0, …)`
printer. A pack is comptime-only: it lowers to flat positional args before
codegen and has no runtime layout, so `sizeOf` and `toLLVMType` bail loudly
rather than inventing a size. 5 unit tests (N=0/1/3, dedup, order/arity
distinctness, distinct-from-tuple, printer).
Also: give TypeTable an arena for the slices its constructors dupe (freed at
deinit), and add the missing `usize`/`isize` arms to `sizeOf` (a latent
non-exhaustive switch) so types.test.zig compiles and runs leak-free.
Pack/tuple spread now parses in tuple-value `(..xs)` / `(..xs.field)`,
tuple-type `(..F(Ts))` / `(..F(Ts.Arg))`, call-arg `f(..xs)` (already),
and closure-sig `Closure(..Ts)` / `Closure(..sources.T)` positions.
Design: the uniform spread node is the existing `spread_expr` (its
operand sub-expression carries the projection `xs.field` and
type-application `F(Ts)` shapes) rather than a new PackExpansion node —
call-arg slice-spread (`..arr`) and pack-spread (`..pack`) are
syntactically identical, so they must share one node, and spread_expr
already serves it with working slice lowering. Closure-sig packs gain
`ClosureTypeExpr.pack_projection` alongside the existing `pack_name`.
Parser-only; sema/lowering land in Phase 2. 6 new parser unit tests +
examples/probes/pack-expansion-parses.sx. Build + 225-suite green.
`..xs: Protocol` (a bare protocol, no `[]`, no `$`) on a variadic
parameter now parses to `ast.Param.is_pack = true` — a heterogeneous
protocol-constrained pack, distinct from a slice variadic
(`..xs: []T`, is_pack=false) and the comptime type-pack (`..$args`,
is_comptime=true). Parser-only: sema/lowering for the pack form land in
Phase 2; existing forms are unaffected (zero examples used a bare
non-slice variadic annotation). Adds three parser unit tests and
examples/probes/pack-param-parses.sx.
Specs the Feature 1 language surface: the three variadic forms
(`[]T` / `..$xs: []Type` / `..xs: Protocol`), the pack-ops table
(`xs.len`, `xs[i]`, `inline for` index + element forms, projection, and
the four spread targets — call args / tuple value / tuple type / closure
sig), position-driven pack projection with the same-name soft warning,
the tuple spread/projection parallels, N=0 semantics, the pack-as-value
diagnostic rule, tuple-based storage + the impl-driven `xx` requirement,
and the canonical Combined/map example. Cross-references from the Tuple
Types and Closure Type sections.
A tuple_init's element values must match its field types exactly — LLVM
`insertvalue` does no implicit conversion. An inferred `pair := (40, 2)`
lowered its elements under the enclosing fn's `target_type` (e.g. main's
s32 return), producing i32 values, while the field types were inferred
independently as s64. The {i64,i64} aggregate was filled with i32
constants, so reading any element back returned garbage (40 + 2^32) and
tuple equality was always false.
lowerTupleLiteral now lowers each element under its resolved field type
(the contextual target tuple's fields when present, else per-element
inference) and coerces to it, so value width always matches field width.
Assignment to a tuple-typed field/element now also propagates the target
tuple type. Adds examples/190-tuple-values.sx as a regression test and
examples/probes/tuple-baseline.sx as the Step 0.4 audit artifact.
Feature 0 complete. addNote/addHelp bundle notes and help-blocks under a
primary diagnostic (handle from new addId/addFmtId); help blocks carry an
optional fix-it line that substitutes the suggested source. renderExtended
now renders primary -> notes -> helps with blank-line separators.
Wire the CLI to the extended renderer (renderErrors -> renderStderr) and
flip render_style default to .extended; the previous renderErrors ->
renderDebug path bypassed render() entirely, so flipping the field alone
was a no-op. 13 diagnostic snapshots re-rendered to the extended format.
Adds RenderStyle (compact/extended), renderExtended/renderExtendedOne
producing the locked Rust-style format (header, --> location arrow, blank
bar, numbered code excerpt, caret line), and dispatches render() through
a render_style field on DiagnosticList. Old render body extracted as
renderCompact and kept as the default so existing snapshots stay
unchanged — F0.3 flips the default.
renderExtendedOne builds on F0.1's extractContext. Helpers digitCount
(line-number column width) and writeRepeated (no writeByteNTimes in
modern std.Io.Writer) are file-private. Line-number column has a min
width of 2 to match Rust's visual style.
7 new tests cover single-line span with carets, warning prefix,
span-less header, triple-digit line widening the column, empty-span
single caret, multi-line span with per-line carets, and the compact-
default regression. All 15 errors tests pass via `zig test
src/errors.test.zig`; 224 regression tests green.
Surfaced gotcha: zig build test doesn't currently exercise src/*.test.zig
files because src/root.zig lacks refAllDecls; adding it exposes
pre-existing breakage in src/ir/lower.test.zig and src/ir/types.zig.
Reverted that addition — out of scope for the lang workstream; unit-test
verification uses direct zig test for now.
Adds LineInfo, ContextLines, and extractContext(allocator, source, span) to
errors.zig — a pure utility that returns the source lines covered by a span
plus columns for caret rendering. Prereq for F0.2's new render path which
will produce Rust-style multi-line diagnostics with code excerpts.
8 unit tests cover the boundary cases: single-line span, multi-line spans
(1 and 2 newlines crossed), span on an empty line, span at end-of-file
without trailing newline, empty source, and offsets beyond source.len
(clamping).
No render surface change yet; F0.2 wires this into a new render mode kept
behind a RenderStyle flag so old gcc-style output remains available during
the transition.
Previously, type aliases (`ShaderHandle :: u32`, `Vec4 ::
Vector(4, f32)`) were resolved at three explicit call sites:
- `resolveTypeWithBindings` fallthrough (lower.zig: was 10481-83)
- Protocol method param resolution (was 11154-61)
- Protocol method return resolution (was 11169-76)
Every other `type_bridge.resolveAstType` caller silently fell into
`resolveTypeName`'s "create empty struct stub" path at the bottom,
materialising the alias name as a fresh `{Name=}` struct instead of
its target type. Symptom: the IR call signature got `{}` parameters
where the user meant `u32` etc.
This pushes the alias check inside `resolveTypeName` itself. A new
`TypeTable.aliases: ?*const std.StringHashMap(TypeId)` borrow is
loaned at `lowerRoot` from the owning Lowering. `resolveTypeName`
consults it before falling through to the stub default. Every
caller of `resolveAstType` (and its recursive helpers — `*Alias`,
`[]Alias`, `?Alias`, etc.) now picks up the same resolution.
The three pre-check sites in lower.zig collapse:
- `resolveTypeWithBindings`: the trailing alias pre-check is gone;
the comment now points at the new path.
- Protocol method param: the `Self → *void` short-circuit stays;
the alias arm is gone — the fallthrough handles it.
- Protocol method return: same shape.
Tests:
- `type_bridge.test.zig` gains `resolveAstType: TypeTable.aliases
resolves named alias` pinning the new behaviour. Demonstrates:
(1) no alias set → unknown name becomes empty struct stub (the
silent-fail shape we're fixing); (2) alias set → resolves to the
alias target; (3) compound forms (`*Alias`) recurse into
`resolveTypeName` for the inner name and pick up the alias.
224/224 example tests pass; zig build test green.
`appendObjcEncoding` previously bailed on `.@"struct"`, which blocked
sx-defined `#objc_class` methods from declaring CGPoint / CGRect /
NSRange-shape signatures — the `class_addMethod` registration path
would emit a "type kind not yet supported by Obj-C encoding"
diagnostic. The helper now emits Apple's `{Name=field0field1...}`
form recursively, with a small `ObjcEncodingStack` (cap 16) that
breaks transitive struct→struct cycles by emitting the abbreviated
`{Name}` form instead of recursing forever.
`{Point=dd}`, `{_NSRange=QQ}`, `{CGRect={CGPoint=dd}{CGSize=dd}}`
all flow through the existing `objc_msg_send` + `class_addMethod`
path with no further plumbing.
Tests:
- `lower.test.zig` gains four cases: optional unwrap (single + nested),
flat struct (CGPoint, NSRange shape), nested struct (CGRect with
CGPoint+CGSize), bringing the helper's test coverage from
primitives + pointers to the full encoding table.
- `examples/ffi-objc-defined-class-02-struct-encoding.sx` exercises
a sx-defined `SxMover` class with `goto(p: Point)` setter and
`here() -> Point` getter end-to-end on macOS; the IR snapshot
confirms `v@:{Point=dd}` and `{Point=dd}@:` land in
`OBJC_METH_VAR_TYPE_` constants wired to `class_addMethod`.
Checkpoint cleanup: the "Next step (M1.2 A.1 — type-encoding
derivation table)" header in CHECKPOINT-FFI.md was stale (A.1
shipped in 6cc016c; A.0–A.7 all done; commit list now linked).
The encoding table stays as reference material.
224/224 example tests pass; zig build test green.
Previously, `t : Type = f64` stored a boxed string carrying the literal
name "f64"; comparisons and `type_of`/`type_name` round-trips lost the
underlying TypeId. This switches `Type` to a runtime-representable Any
pair: `{ tag = .any.index() (meta-marker), value = TypeId.index() }`.
Mechanism:
- `const_type` emits a 16-byte Any aggregate via insertvalue.
- `TypeId.any` advertises 16 bytes / 8-byte alignment so structs that
embed `t: Type` size correctly under verifySizes.
- `lowerBinaryOp` folds `==`/`!=` between static type-refs to a
`const_bool`, and decomposes runtime Any-vs-Any compares via
`unbox_any` so LLVM doesn't see icmp on aggregates.
- `lowerMatch`'s `is_type_match` path unboxes Any-typed subjects to
the i64 type tag before the switch, so `case type:` etc. fire.
- `lowerRuntimeDispatchCall` (used by `case T: ... cast(t) val`) does
the same unbox for the type-tag arg.
- `type_of(val: Any)` rebuilds an Any with `{.any, tag_of(val)}` so
the result is itself a `Type` value, not a bare i64.
- `buildPackSliceValue` stops re-boxing const_type — the value is
already canonical Any.
- `__sx_type_names` now indexes by TypeId across the whole table
using the new `types.formatTypeName` (structural names for `*T`,
`[]T`, `[N]T`, `?T`, `Vector(N,T)`, function/closure/tuple) so
runtime `type_name(t)` works for compound types.
- `interp.zig`'s comptime `type_name` accepts either the bare
`.type_tag` Value or the Any-boxed aggregate it now sees.
- `scanDecls` registers `Vec4 :: Vector(4, f32)` style aliases in
`type_alias_map` (before the `fn_ast_map` check; `Vector` IS a
`#builtin` fn). Lets `Vec4` in expression position lower as
`const_type(<vector tid>)`.
- `isStaticTypeArg` becomes scope-aware: a name shadowed by a runtime
local is not static. `isStaticTypeRef` is the symmetric helper for
the eq fold.
- `inferExprType` returns `.any` for bare type names (identifier and
type_expr) so pack arg types are correct.
Side effect: `print("{}", Vec4)` now prints the structural name
`Vector(4,f32)` rather than the alias literal `Vec4` — 12-meta's
expectation updated. Aliases stay pointer-equal to their target
(`Vec4 == Vector(4, f32)` is true).
Tests:
- examples/189-type-all-interactions.sx: 12-section comprehensive
coverage — literal `==`, `type_of(value) == T`, `Type` var storage,
`type_name` (static + runtime), printing Type values, generic
dispatch via `$T: Type`, `identity($T, val)`, `Wrap($T)`, reflection
builtins (`size_of`, `align_of`, `field_count`, `type_eq`),
`..$args` pack walking, `Type` in struct field, compound type
literals (`*Point`, `[4]s32`, `[]bool`, `?f64`).
- examples/12-meta.sx: expected output updated to reflect structural
name for the Vec4 alias path.
- ffi-objc-call-06-sret-return.ir: regenerated to absorb the new
type-name strings now emitted globally.
223/223 examples pass.
`abiCoerceParamType` had a libc-friendly heuristic: sx `string` /
`[]T` slice → `ptr` (drop the len, just pass the start pointer).
The heuristic is right for `#foreign` decls that mirror libc
signatures (`puts(const char *)`, `strlen(const char *)`); it's
wrong for sx-internal `callconv(.c)` (e.g. block trampolines) where
both sides see and exchange the full slice.
Split via a new `abiCoerceParamTypeEx(ir_ty, llvm_ty,
is_foreign_c_api)`. The old single-arg form forwards with
`is_foreign_c_api = true` so every call site that already collapses
keeps doing so. The function-decl emit at lines 1442 / 1454 now
passes `func.is_extern` — sx-internal `callconv(.c)` declarations
take the false path and preserve the slice as `{ptr, i64}` →
`[2 x i64]` via the general struct-coerce branch (true C ABI for
a 16-byte aggregate: passed in x0+x1 on AArch64).
`examples/188-block-string-arg.sx` flips green ("got: <hello>");
suite stays at 222/222. Foreign-decl call sites
(objc msg_send / JNI / direct extern calls) keep the libc
collapse — they pass `is_foreign_c_api = true` via the legacy
`abiCoerceParamType` shim.
Generic `Into(Block) for Closure(string) -> void` (step 5.2) emits
a trampoline whose `callconv(.c)` param type collapses through
`abiCoerceParamType`'s `string → ptr` heuristic — the libc
"char *" convention. The caller side (typed fn-pointer cast +
indirect call through `b.invoke`) keeps the full `{ptr, i64}`
slice. Result on AArch64: caller passes 16 bytes in x0+x1,
trampoline reads 8 bytes from x0 only, the slice len is lost or
mis-tracked, and the trampoline's `memcpy` from the half-formed
string segfaults.
`examples/188-block-string-arg.sx` pins the post-fix behaviour
("got: <hello>"). Today's run segfaults inside the trampoline's
first read. The next commit splits `abiCoerceParamType` into a
foreign-only path (extern decls keep the libc collapse) and a
preserve-slice path (sx-internal `callconv(.c)`).
New reflection-builtin arm in `tryLowerReflectionCall` for
`compile_error(msg)`. Resolves the string literal at lower time,
emits a focused diagnostic at the call site's span via
`self.diagnostics.addFmt(.err, ...)`, and returns a void-typed
constant so the call expression can sit in any statement position.
Three error shapes:
- Zero args → "compile_error requires a string argument".
- Non-string-literal arg → "compile_error argument must be a
string literal" (we need the message text at lower time;
runtime expressions can't be reported as compile errors).
- Valid literal → the literal text is the error message verbatim.
`examples/187-compile-error.sx` flips green (the `unresolved`
diagnostic from the lock-in commit becomes the focused
`intentional compile error from #run`). 221/221.
`compile_error(msg)` raises a build-time diagnostic at the call site
with `msg` as the error text. The arg must be a string literal —
runtime expressions can't be reported as compile errors. Used by
builder fns to reject malformed pack shapes / arg combinations
cleanly instead of silently emitting wrong code.
Today: `unresolved 'compile_error'`. Expected (post-fix): focused
diagnostic with the literal message at the call site's span. The
next commit adds the lowering arm.
All six produce their target outputs cleanly today; renamed out of
the `issue-*` namespace per CLAUDE.md "Resolving an open issue":
| Old | New |
|----------------------|-------------------------------------------|
| issue-0032 | 181-impl-duplicate-same-file |
| issue-0041 | 182-compound-type-in-expression |
| issue-0042 | 183-type-alias-size-align |
| issue-0044 | 184-objc-defined-class-method-self |
| issue-0045 | 185-pack-fn-comptime-return |
| issue-0046 | 186-nested-comptime-return |
Comment headers tightened to feature-focused (drop the issue-NNNN
provenance — that's in git history now). Missing expected `.txt` /
`.exit` files captured for 0041 + 0042 (they were untracked because
the bugs were fixed silently in adjacent work).
`examples/issue-*` after this commit: just `issue-0030.sx` — a
feature request (`extern G : T;` cross-file globals) that's never
been implemented. Staying in the issue namespace as a parked
proposal until the feature lands or gets formally rejected.
220/220 example tests + `zig build test` green.
Both repros emit their target diagnostics cleanly today (verified
2026-05-28 against HEAD):
- `issue-0033` → "no visible xx conversion from 's64' to 'Wrap'
— impl exists in another module but is not imported". Catches
the case where an `impl Into(X) for Y` is registered globally
via one module's import chain but is NOT transitively imported
by the file containing the `xx` site.
- `issue-0034` → "duplicate xx conversion from 's64' to 'Wrap':
impls in <a> and <b>". Catches two impls covering the same
(Source, Target) pair both reachable from a single `xx` site.
Renamed to focused feature names:
- `issue-0033*` → `179-impl-visibility*` (4 files: main + impl +
types + user).
- `issue-0034*` → `180-impl-duplicate*` (4 files: main + impl-a +
impl-b + types).
Path references inside the files updated. Comment headers tightened
to feature-focused (drop issue-NNNN provenance — that's in git
history now). Expected `.txt` / `.exit` files captured against the
full diagnostic text and exit code 1.
The `issue-*` namespace in `examples/` now shrinks to the literal
list of UNRESOLVED bug repros. 218/218.
Triage pass: every issue file in `issues/` was re-verified against
HEAD. Three (0041, 0042, 0043) reproduce no longer — they were
silently fixed by adjacent work since the issue was filed. 0047
landed in the previous commit. All four header sections now lead
with **FIXED** + a one-line locator so the next reader doesn't
re-investigate.
After this, `issues/` is the actual open-issue list:
| Issue | Status |
|---|---|
| 0041 | FIXED (silently, by alias/parser work) |
| 0042 | FIXED (silently, type_alias_map lookup landed) |
| 0043 | FIXED (silently, lazy-lower foreign-class dispatch) |
| 0044 | FIXED |
| 0045 | FIXED |
| 0046 | FIXED |
| 0047 | FIXED (commit 0119c9c) |
| 0048 | FIXED (commit 0ede097) |
| 0049 | FIXED (commit b5301c4) |
| 0050 | FIXED (commit 5316bf7) |
No open issues remain. The files stay in tree as a record; new
issues take the next free number (0051).
`#run` / post-link callback `print` output was reaching stderr via
`std.debug.print` flushes from three sites. The runtime JIT path
already writes to fd 1 (stdout) directly. Anyone redirecting one
stream saw the two halves disappear in different places.
Switches all three flush sites + the `--- build done ---` delimiter
in main.zig to `std.c.write(1, ...)` so build-time and runtime
prints share the stream the user wrote them against (they typed
the same `print(...)` at both call sites — there's no reason for
them to land on different streams). Test runner uses `2>&1` so
snapshots are unaffected; suite stays at 218/218.
Closes issue-0047.
`format` and `print` move from `..args: []Any` to `..$args`. The
pack-fn machinery monomorphises each call shape, so the
build_format-emitted body's `any_to_string(args[i])` substitutes
to the i-th concrete-typed call arg via packArgNodeAt — no more
runtime Any-boxing for static args. The Any boxing path still
fires for arg positions whose types collapse to `.any` (already
Any-typed inputs).
Net effect:
- Calls with statically-typed args produce per-shape monos
(`print__ct_<fmt_hash>__pack_s64_string_bool` etc). The mono
cache key now reflects both the format string AND the arg
types, so different shapes get distinct emit paths.
- Compile-time arity errors are now possible (callers passing
the wrong number of args mismatch the mono's positional
binding instead of silently mis-boxing).
- Optionals flow through the new `case optional:` arm in
`any_to_string` (commit ce77867); the variadic auto-unwrap
in `packVariadicCallArgs` stays as a fast-path but is no
longer load-bearing.
IR snapshots regenerated for 13 tests where the print/format
mono shape changed the string-constant pool: 142, the ffi-jni
test cluster, ffi-objc-call-03/06, ffi-objc-dsl-07. Test
08-types' undef-memory-read snapshot also shifted (the test
exercises `field = ---` reads from a print call's stack
neighbours; the new pack-mono lays out its stack frame
differently, so the previously-stale 1s now read as 0s — same
undefined behaviour, different garbage).
218/218 example tests + `zig build test` green.
Three additional arms that previously silently fell through to
`.s64`:
- `.null_coalesce`: `lhs ?? rhs` now returns the inner type of
lhs's optional (when applicable), else the rhs's inferred type.
Without this, `print("{}\n", iw ?? 0.0)` for `iw: ?f32`
inferred as s64 and the float value got truncated through the
pack-mono's Any boxing.
- `.field_access` struct constant: `Phys.GRAVITY` (a `Struct.CONST`
declaration) now consults `struct_const_map` for the resolved
field type. Previously the path hit only `lowerFieldAccess`'s
constant-resolution shortcut, not the AST-level `inferExprType`,
so pack-fn callers misinferred the const's type as `.s64`.
- Reflection builtins (`type_name`, `type_eq`, `has_impl`,
`field_count`, `field_index`, `field_name`, `is_flags`,
`type_of`, `field_value`): their return types live outside
`resolveBuiltin`'s table (they dispatch via
`tryLowerReflectionCall` instead). Recognise them directly in
the `inferExprType` call arm so pack-fn callers mangle the
results with the right tag (.bool for `type_eq` / `has_impl` /
`is_flags`, .string for `type_name` / `field_name`, etc).
All three holes surfaced while attempting the print/format
`..$args` migration; the fixes themselves are general
improvements and stand independently. 218/218.
Closes the optional-through-Any gap that test 178 pinned.
Stdlib (`library/modules/std.sx`):
- New `optional_to_string :: (o: $T) -> string` returns `"null"`
when the optional is None, otherwise recurses through
`any_to_string` on the unwrapped inner value. Per-shape
monomorphisation re-emits this for each concrete `?T`.
- `any_to_string` grows a `case optional:` arm that dispatches
through `cast(type) val` (same shape as `case struct:` etc.).
The cast picks up the dynamic optional type from the Any tag.
Compiler (`src/ir/lower.zig`):
- `resolveTypeCategoryTags` recognises "optional" as a dynamic
category, scanning the TypeTable for `info == .optional`. The
type-switch dispatch then routes any ?T tag into the optional
arm.
IR snapshots regenerated where the optional addition shifted
constant pool / string numbering: 142, ffi-objc-call-06,
ffi-objc-dsl-07. 218/218 (test 178 included).
The variadic auto-unwrap in `packVariadicCallArgs` stays in
place — direct `print(opt)` calls still flow through it. The new
arm closes the gap for struct fields, slice elements, and any
other path that boxes an optional before stringifying.
`examples/178-any-to-string-optional.sx` prints a struct whose
three fields are `?s64` / `?string` / `?bool`, in both Some and
None form. The struct-print path goes through `field_value(s, i)
-> Any` and then `any_to_string(Any)`. Today: `any_to_string`
has no `case optional:` arm and `resolveTypeCategoryTags` has no
"optional" category — every optional field falls through to the
`<?>` default. Expected output captures the working post-fix
form (`a: 42`, `b: hi`, `c: true` for Some; `null` across the
board for None).
The next commit adds `optional_to_string` + `case optional:` to
std and "optional" to `resolveTypeCategoryTags`. Variadic
auto-unwrap (`packVariadicCallArgs`) keeps printing direct
`print(opt)` calls correctly today; this fix closes the gap for
struct fields, slice elements, and anywhere else an optional
flows through Any.
Three general fixes to AST-level type inference that previously fell
through to `.s64`:
- `inferGenericReturnType` resolved the function's return type only
when `tmp_bindings` was non-empty; otherwise it bailed to `.s64`,
which silently mis-typed pack-fns with non-generic literal return
types (e.g. `walk(..$args) -> string`). Always resolve via
`resolveTypeWithBindings`, even with empty bindings.
- `inferExprType` `binary_op` arm: `.in_op` now returns `.bool`
alongside the other comparison/logical ops. Previously the `else`
branch returned the LHS type (e.g. `2 in (1,2,3)` → `s64`).
- `inferExprType` field-access call arm: when a namespace-qualified
call (`pkg.hello()`) hasn't been lowered yet, consult `fn_ast_map`
for the qualified name AND the bare field name (matches
`lowerCall`'s effective-name resolution order). Without this,
cross-module calls returned `.s64`.
Surfaces during the still-deferred print/format → `..$args`
migration where the pack mono's per-position type tag depends on
correct call-arg type inference. The fixes themselves are general
improvements that stand independently. 217/217.
The special-case `return self.fail("legacy variadic syntax ...")`
in `parseParams` is gone. `parseTypeExpr` already errors naturally
on a leading `..` (now reported as "expected type name"), which
is enough — the language-level cutover happened in the previous
commit; no need for the parser to keep a migration breadcrumb.
Removes `__block_invoke_void` / `__block_invoke_bool` and their
companion `Into(Block)` impls from
`library/modules/std/objc_block.sx`. The generic
`Into(Block) for Closure(..$args) -> $R` impl from step 5.2 now
covers both shapes (and every other closure shape) via per-mono
`#insert build_block_convert($args, $R)` source emission.
Net stdlib shrinkage: ~52 lines, two trampolines + two per-shape
impls down to zero. Adding a new block-shape consumer no longer
requires touching stdlib — the impl emits per-call-shape on
demand.
`examples/95-objc-block-noop.sx` (zero-arg closure) and
`examples/96-objc-block-multi-arg.sx` (user-declared per-shape
impl for `Closure(s32, *void) -> void`) still pass: 95 routes
through the new generic, 96 keeps its in-file impl as a
documentation example of the user-declares-their-own path.
Suite at 217/217.
Adds the generic `impl Into(Block) for Closure(..$args) -> $R`
in `library/modules/std/objc_block.sx` alongside the existing
hand-rolled `Closure() -> void` and `Closure(bool) -> void`
impls. The convert body is a single
`#insert build_block_convert($args, $R);` — per-call-shape
monomorphisation re-runs the builder so each closure shape gets
its dedicated nested `callconv(.c)` trampoline + Block literal.
The impl-mono path threads pack types through
`pack_bindings[args]` and the single-type return through
`type_bindings[R]`. Both need to be visible to the body's
`$args` / `$R` expression-position references — the existing
lowering only consulted `pack_arg_types` (set by pack-fn mono,
not by tryPackImplMatch). Two small extensions:
- `lowerExpr`'s `.comptime_pack_ref` arm now consults
`pack_arg_types` → `pack_bindings` → `type_bindings` in order,
treating a `type_bindings` hit as a single `const_type(T)`
value rather than the slice form.
- `resolveTypeArg` grows a `.comptime_pack_ref` arm that maps
the same name through `type_bindings` so type-arg positions
(e.g. inside `type_name(...)` in the builder body) resolve
the bound single Type.
- `type_bridge.isTypeShapedAstNode` lists `comptime_pack_ref`
and `pack_index_type_expr` as type-shaped so
`buildTypeBindings`'s strategy-1 explicit-arg path picks
them up when calling a `$T: Type`-generic fn.
`examples/177-generic-into-block.sx` flips green: a
`Closure(s64, s64) -> void` (no hand-rolled impl) is converted
through the generic impl, its block invoked via a typed
`callconv(.c)` fn-pointer, and the closure's side effects land
in the host globals. Hand-rolled impls remain for `()` and
`(bool)` shapes; 5.3 deletes those once a focused test covers
their behaviour through the generic path. Suite at 217/217.
`examples/177-generic-into-block.sx` exercises a closure shape
(`Closure(s64, s64) -> void`) that stdlib's hand-rolled
`Into(Block)` impls don't cover. Today: the focused diagnostic
"no `Into(Block) for cl_s64_s64__void` impl — add a
per-signature `__block_invoke_<sig>` trampoline + Into impl
alongside the existing ones in modules/std/objc_block.sx, or
declare it in your own code" fires at the `xx cl : Block` site.
The next commit adds the generic
`impl Into(Block) for Closure(..$args) -> $R` to
`library/modules/std/objc_block.sx` (wiring `#insert
build_block_convert($args, $R)` from step 5.1.B) plus the
lowering plumbing needed to make pack + single-type `$` refs
work inside the impl's monomorphisation. The test then flips
green — the per-shape trampoline emitted by build_block_convert
ferries (10, 20) through to the sx closure and the side-effect
stores land in g_a / g_b.
`build_block_convert(args: []Type, $ret: Type) -> string` emits
the convert-body source for the generic `Into(Block) for
Closure(..$args) -> $R` impl (step 5.2):
1. A nested `__invoke :: (block_self: *Block, arg0: T0, ...) ->
R callconv(.c) { ... }` trampoline matching the per-shape
Apple Block ABI.
2. A `return Block.{ ... };` literal whose `invoke` slot points
at the nested trampoline via `xx @__invoke`.
Void-returning shapes emit `typed_fn(block_self.sx_env, args...)`;
non-void emits `return typed_fn(...)`. Per-position arg names
follow `arg0`, `arg1`, ... in declaration order; the typed-fn
cast reconstructs the closure's call signature so the trampoline
hands control back to `sx_fn` with the right argument layout.
`examples/176-build-block-convert.sx` flips green (216/216).
Step 5.1.A of the FFI plan (variadic heterogeneous type packs →
generic `Into(Block)` impl). The eventual step-5.2 impl body will
read `#insert build_block_convert($args, $R);` to emit a per-shape
`__invoke` `callconv(.c)` trampoline + Block literal. 5.1.A pins
the builder's expected output verbatim across three void-returning
pack shapes (0, 1, 2 args) plus one non-void shape (`f64 -> s32`)
that exercises the `return typed_fn(...)` branch.
Today: 4× "unresolved 'build_block_convert'" diagnostics — the
builder isn't in stdlib yet. The next commit adds it to
`library/modules/std/objc_block.sx` and the test flips green.
The per-position type names in the emitted source come from
`type_name(args[i])`; the slice itself is `[]Type` flowing through
the new-form variadic + bare-`$args` path that the recent
issues-0048/0049/0050 fixes unblocked.
Adds the same save+null+defer-restore block at the top of
`monomorphizeFunction` that landed in `lazyLowerFunction` for
issue-0048. The outer pack-fn's `pack_arg_nodes` /
`pack_param_count` / `pack_arg_types` / `inline_return_target`
are now suppressed for the duration of the generic mono's body
lowering and restored on exit.
`examples/175-generic-fn-pack-state-leak.sx` flips green
(len=0/1/2/4 across the four pack shapes); suite stays at
215/215.
A generic fn (with `$T: Type` type params) called from inside a
pack-fn mono inherits the outer pack maps during its OWN body
lowering. Same root cause as issue-0048 — the lowering helper
doesn't save/null `pack_arg_nodes` / `pack_param_count` /
`pack_arg_types` — but on the generic-mono path
(`monomorphizeFunction`, ~line 8718) rather than
`lazyLowerFunction`.
`examples/175-generic-fn-pack-state-leak.sx` calls
`build(args: []Type, $ret: Type)` from a four-shape pack-fn. The
expected output is `len=0 / 1 / 2 / 4`; today's run reports
`len=0` for every shape because `build__void` was first
monomorphised under `probe()`'s mono (N=0) and `args.len` got
constant-folded to 0 inside the cached body. The next commit
adds the same isolation pattern to `monomorphizeFunction`.
Step 5 of the FFI plan (generic `Into(Block)` impl) needs the
`build_block_convert(args: []Type, $ret: Type) -> string` builder,
which trips this leak directly.
Parser hard-rejects the legacy `name: ..T` form with a one-line
migration message pointing at the new `..name: []T` shape. The
leading-`..` form is the one the lowering paths
(`resolveParamType` / `packVariadicCallArgs`) treat as canonical
post-issue-0049; leaving both forms accepted invited the same
class of cross-module emit crashes any time a `..T`-form decl in
stdlib crossed an import boundary.
`specs.md` updated alongside: the Variadic Functions section now
documents `..name: []T` as the surface form, with notes on
homogeneous vs `[]Any` boxing and the `..` spread at call sites.
Inline references to `args: ..Any` in §7 and §8 refreshed.
Stdlib:
- `format` / `print` in std.sx — both move from `args: ..Any` to
`..args: []Any`. The post-issue-0049 lowering makes this safe
across module boundaries.
- `open` in fs.sx — `args: ..s32` → `..args: []s32`. Foreign
C-variadic semantics are preserved (the trailing `, ...` lands
in the generated `declare` regardless of which surface form is
used).
Examples:
- `19-varargs.sx` — `sum` / `print_all` migrated.
- `20-any-varargs.sx` — `print_any` / `count` migrated.
- `50-smoke.sx` — `typed_sum` migrated.
- `120-interp-variadic-any.sx` — comment-only update referencing
the new form.
- `ffi-foreign-cvariadic.sx` — three C-variadic foreign decls
migrated; header comment refreshed.
Suite stays at 214/214. The legacy `name: ..T` surface form is
still accepted by the parser; rejection follows in a later commit
once specs.md catches up.
Both helpers now detect when a variadic param's declared type is
already a slice (`..name: []T`) and use it as the element-shape
container directly, instead of wrapping it once more. The legacy
form (`name: ..T`) still wraps as before. Without the unwrap, the
new-form `..parts: []string` ends up with a callee-side slot type
of `[]([]string)`, while the call-site marshal pack emits a
`[N x string]` array, and downstream LLVM emission crashes on
the resulting null Refs (`LLVMBuildExtractValue` inside
`emitStrCmp`).
`examples/121-ios-sim-bundle.sx` (which exercises stdlib's
migrated `path_join`) and the focused regression
`examples/174-new-form-variadic-cross-module.sx` both flip green;
suite stays at 214/214. The remaining stdlib decls (`format` /
`print` / `open`) and example fixtures land in the follow-up
migration commit.
Migrating stdlib's `path_join` to the new variadic syntax
(`(..parts: []string) -> string`) surfaces a latent compiler bug:
`resolveParamType` and `packVariadicCallArgs` treat the new-form
declaration the same as the legacy `parts: ..string` and wrap the
element type in `sliceOf` regardless of whether it already is one.
The new form's `[]string` becomes `[][]string`; the call-site
marshal pack emits `[N x string]` (correct) but the callee stores
its slice param into a `[]([]string)`-typed slot. The shape
mismatch propagates as null/undef Refs that crash
`LLVMBuildExtractValue` inside `emitStrCmp` during emission.
`examples/121-ios-sim-bundle.sx` (existing) and the new focused
`examples/174-new-form-variadic-cross-module.sx` both fail today
with the segfault. The next commit fixes `resolveParamType` +
`packVariadicCallArgs` so both flip green. Stdlib's `format` /
`print` / `open` and the example fixtures stay on the legacy form
in this commit — they migrate in the follow-up cleanup commit.
`lazyLowerFunction` now saves and nulls `pack_arg_nodes`,
`pack_param_count`, `pack_arg_types`, and `inline_return_target`
before lowering the callee's body, then restores them via defer.
Same shape as the save/restore already in `createComptimeFunction`
(issue-0046 fix). Without this, a lazily lowered regular fn called
from inside a pack-fn mono inherited the outer pack maps, and the
`<pack_name>.len` intercept in `lowerFieldAccess` constant-folded
the callee's same-named param to the outer mono's arity.
`examples/173-pack-bare-args-cross-call.sx` now passes; previously-
green tests untouched. 213/213.
Bare `$args` evaluated inside a pack-fn body has the right `.len` /
per-element types inline, but the moment the same slice is passed
as an argument to another function, the callee silently reads
length 0 and every element comes back as undef.
Cause (per issue file): `lazyLowerFunction` saves/restores builder
state but not `pack_arg_nodes` / `pack_param_count` /
`pack_arg_types` / `inline_return_target`. When a regular fn like
`describe(args: []Any)` is lazily lowered from inside a pack-fn
mono, the outer pack maps are still active; `lowerFieldAccess`'s
`<pack_name>.len` intercept fires on `describe`'s same-named param
and bakes the outer mono's arity as a constant into describe's IR.
Every subsequent shape's call to describe returns that constant.
`examples/173-pack-bare-args-cross-call.sx` exercises four shapes
(0, 1, 3, 5 elements) through the same `describe(args: []Any)`
walker. The expected output holds the per-position type names
(`[s64]`, `[s64, string, bool]`, etc); today's diff fails — the
walker reads `args.len = 0` for every shape and returns `[]`. The
next commit fixes `lazyLowerFunction`.
Step 4A final-slice's smoke test. Exercises the FULL surface
step 5's generic Into(Block) impl needs to operate:
1. A pack-fn binds $args (whole pack as []Type).
2. The body walks `list := $args` at INTERP time.
3. Per position, calls `type_name(list[i])` — the dynamic
form that emits `callBuiltin(.type_name, ...)` at lower
time, dispatched at interp time to read the runtime
Value.type_tag and return the concrete type name.
`examples/172-pack-builder-smoke.sx` exercises four call
shapes via #run:
describe() → []
describe(42) → [s64]
describe(42, "hi") → [s64, string]
describe(true, 3.14, "x", 99) → [bool, f64, string, s64]
Each call shape builds its own [N x Any] slice of .type_tag
values at lowering time, the interp walks the slice, and the
per-element type names come out kind-honestly.
212/212 example tests + zig build test green.
Fix for the silent .s64 fall-through in `type_name(<dynamic-arg>)`.
`tryLowerReflectionCall` now splits on `isStaticTypeArg(node)`:
- Static (type_expr / identifier / pack_index_type_expr / pointer
/ array / slice / optional / many_pointer / function_type_expr
/ tuple_literal / call) → fold to const_string at lower time
(today's fast path).
- Dynamic (index_expr, field_access, runtime locals, anything
else) → emit `callBuiltin(.type_name, [arg_ref])`. The interp's
arm (commit 9600ba5) reads the runtime `.type_tag` Value and
returns the per-position name.
`isStaticTypeArg(node)` is a new helper mirroring the explicit
arms of `resolveTypeArg`. Lives alongside resolveTypeArg in
lower.zig; documented to track shape changes together.
emit_llvm: the comptime reflection builtins (`type_name`,
`type_eq`, `has_impl`) now emit a silent undef-i64 placeholder.
Same reasoning as 4A.bare.1.B's relaxation of const_type's
emit_llvm arm: the JIT compiles the containing fn module-wide
even if main never calls it, so emit-time noise here is just
dead-from-main's-perspective code. Real misuse — passing a non-
Type value to one of these — is caught by the interp arm's
`asTypeId orelse bailDetail`.
`examples/171-pack-dynamic-type-name.sx` flips from "s64s64"
(silent .s64 fold per element) to "s64string" (per-position
correct via interp arm). Test runs `walk(42, "hi")` at `#run`
time so the dynamic path executes in the interp.
211/211 example tests + zig build test green.
Step 4A final follow-up's lock-in. `type_name(<arg>)` where
<arg> is NOT a statically resolvable type expression (e.g.
`list[i]` indexing into a `$args`-derived `[]Type` slice)
silently folds to "s64" today because `resolveTypeArg`'s
index_expr fall-through returns `.s64` (the catch-all `else =>
.s64` at the bottom of the switch).
This is exactly the kind of silent unimplemented arm the
project's REJECTED PATTERNS section forbids — the user gets
"s64" for every element of an arbitrary pack, not the per-
position concrete type they expect.
`examples/171-pack-dynamic-type-name.sx` exercises a builder-
shaped fn: walks `$args` via runtime indexing, calls
`type_name(list[i])` per position, concatenates the results.
For `walk(42, "hi")` the expected output is "s64string".
Today's output is "s64s64" — the silent fold strikes twice.
Cadence shape 2: expected output is the WORKING shape; today's
diff fails. Next commit teaches `tryLowerReflectionCall` to
detect "arg not statically resolvable" and emit a builtin_call
to `.type_name` so the interp's runtime arm (wired in commit
9600ba5, M5.A.next.4.1) handles the dynamic case.
210/210 + 1 expected-failing = 211 total. zig build test green.
Step 4A final-slice fix. Bare `$<pack_name>` (no `[<int>]`)
in expression position now parses + lowers to a comptime
`[]Type` slice value carrying one `const_type(TypeId)` per
pack element.
Plumbing:
- src/ast.zig: new `ComptimePackRef { pack_name }` node +
`comptime_pack_ref` variant in Data.
- src/parser.zig: `parsePrimary`'s `$` arm makes `[` optional
after the pack name. With `[<int>]` → existing
`pack_index_type_expr` (single Type value). Without → new
`comptime_pack_ref` (whole pack as []Type).
- src/sema.zig: adds the no-op switch arms for the new node
in `analyzeNode` and `findNodeAtOffset`.
- src/ir/lower.zig: `lowerExpr` arm reads `pack_arg_types[name]`
and calls `buildPackSliceValue(arg_tys)`. The helper allocas
a `[N x Any]` array, emits one `const_type(arg_tys[i])` per
slot, then a slice `{data_ptr, len}` aggregate. No active
binding → focused diagnostic + null slice placeholder. The
IR slice element type is `Any` (matches the today's
`Type → .any` mapping in type_bridge); the interp stores
raw `.type_tag` Values directly (NOT Any-boxed) so
`args[i]` at interp time reads a Type value.
- src/ir/emit_llvm.zig: relaxed `const_type` to silently emit
undef-i64 instead of the previous stderr-noisy bail. Storage
of Type values in runtime aggregates is harmless (undef in,
undef out). Use-site misuse is caught by the bails on
type_name/type_eq/has_impl and the bitcast guard.
`examples/170-pack-bare-value.sx` flips from the parse-error
lock-in to "0/1/3/4" — four call shapes of `len_of(..$args) ->
s64 { list := $args; return list.len; }`. The slice's `.len`
field carries the per-mono pack arity.
210/210 example tests + `zig build test` green.
The remaining 4A.bare slices (4 and 5) — resolveTypeArg
silent-arm fix for index_expr + smoke test of a real builder
walking $args — are separate commits per the cadence rule.
Step 4A final slice's lock-in. `$args` (whole pack) as a bare
expression should evaluate to a comptime `[]Type` slice value
— the whole pack passed through as data so builder fns can
walk it.
Today's parser arm (commit fd03b58, M5.A.next.4.3) requires
the `[<int_literal>]` form: bare `$<pack_name>` hits the
focused "expected '[' after '$<pack_name>'" diagnostic I added
when wiring the indexed access.
`examples/170-pack-bare-value.sx` exercises four call shapes
of a pack-fn whose body binds `list := $args` then returns
`list.len`. Expected output (post-fix) is "0/1/3/4" per call.
Today the parser rejection diff makes the test fail —
209/209 + 1 expected-failing = 210 total.
Cadence shape 2: expected output is the WORKING shape; pre-fix
the parser-error diff fails. Next commit lands the parser
extension + AST node + lowering and the test flips green.
