Writing a Vector lane (`v.x = …`, `.y/.z/.w` + colour aliases) panicked
with "unresolved type reached LLVM emission". The store path had no
vector branch: a `.field_access` target on a Vector fell through to
struct-field lookup, matched nothing, left `field_ty = .unresolved`, and
built a `ptrTo(.unresolved)` that tripped the LLVM emission guard. The
read path resolved the lane fine — the two had diverged (issue-0083
two-resolver class).
Extract a shared `Lowering.vectorLaneIndex` resolver and route BOTH paths
through it. The read path (`lowerFieldAccessOnType`) delegates to it,
dropping its silent `else 0` fallback. A new vector branch in
`lowerAssignment` GEPs a typed pointer to the lane (`structGepTyped`) and
stores via `storeOrCompound` (plain + compound). `emitStructGep` now
addresses a vector base type with a `[0, lane]` GEP. A non-lane field now
reports field-not-found on both paths instead of silent-lane-0 / panic.
Regression: examples/1506-vectors-lane-store.sx (panicked pre-fix, now
reads back written values) + a vectorLaneIndex unit test. Resolves issue
0086; spec documents element assignment.
The issue-0092 fix guarded the numeric-limit accessor intercept against
raw value shadowing using only lexical Scope.lookup. The ordinary
identifier field-access path resolves a value through THREE sources
(scope / program_index.global_names / program_index.module_const_map),
so a backtick raw identifier bound at module scope — a global
`` `f64 := Box.{…} `` or a module constant `` `f64 :: Box.{…} `` — still
folded `` `f64.epsilon `` to the numeric limit instead of reading the
value's field (issue 0093, plus the module-const variant: same root
cause, same fix).
Fix: a single shared helper Lowering.identifierBindsValue(name) that
returns true when the name resolves through scope OR global_names OR
module_const_map. Used in BOTH lowerNumericLimit (lower.zig) and the
numeric-limit inference arm (expr_typer.zig) so the two resolvers can't
desync (issue-0083 class). A bare `f64.epsilon` / `s32.max` (a
.type_expr receiver) still folds even when a raw value of the same
spelling is bound — the bare receiver is never value-shadowed.
- examples/0161: extended to exercise all three binding kinds — a
GLOBAL `` `f32 ``, a MODULE-CONST `` `s16 ``, and LOCAL
`` `f64 ``/`` `s32 ``/`` `u8 `` — each reading its field while the
bare spelling still folds.
- src/ir/expr_typer.test.zig: unit test pinning the global +
module-const sources of the shared guard.
- issues/0093: RESOLVED banner (3-source root cause + fix, module-const
variant folded in).
- specs.md / readme.md: numeric-limit shadow note now source-agnostic
(local / global / module-const).
The numeric-limit accessor intercept (NL.1 integer `.min`/`.max`, NL.2 float
`.epsilon`/`.min_positive`/`.true_min`/`.inf`/`.nan`) treated ANY receiver
whose text matched a builtin numeric type name as a TYPE receiver, without
first checking for an in-scope VALUE binding. An F0.6 backtick raw identifier
(`` `f64 := … ``) binds a local under the stripped name `f64`; field access on
it (`` `f64.epsilon ``) parses as an `.identifier` receiver, which the intercept
silently folded to the type's numeric limit — a silent-wrong-value bug
(issue 0092).
Fix: for `.identifier` receivers, prefer an in-scope value binding
(`Scope.lookup`) over the fold — defer to ordinary field lowering when the
identifier resolves to a value. `.type_expr` receivers are unambiguous types
and are never shadowed, so a bare `f64.epsilon`/`s32.max` still folds even in a
scope where `` `f64 `` is bound (the parser classifies a bare builtin name as a
`.type_expr`). Mirrored in expr_typer.zig so inference matches lowering
(avoids the issue-0083 two-resolver desync). Float-only-on-int and
non-numeric-receiver errors are unchanged.
- src/ir/lower.zig: value-binding guard in lowerNumericLimit.
- src/ir/expr_typer.zig: same guard in the numeric-limit inference arm.
- src/ir/expr_typer.test.zig: unit test pinning the two-resolver agreement.
- examples/0161-types-numeric-limit-value-shadow.sx: regression — raw
`` `f64 ``/`` `s32 ``/`` `u8 `` value reads coexisting with bare folds.
- issues/0092: RESOLVED banner.
- specs.md / readme.md: receiver-vs-shadowing-value-binding note.
Finish NL.2 on top of the WIP compiler impl (2e9e4fe): f32/f64 expose
.min/.max plus the float-only .epsilon/.min_positive/.true_min/.inf/.nan,
folded via the shared lowerNumericLimit intercept + builder.constFloat.
- examples/0159: pins every f32/f64 accessor by untagged-union bit
reinterpret against exact IEEE-754 hex (true_min read before any
arithmetic — FTZ/DAZ), plus the defining-property checks
((1+eps)!=1 / (1+eps/2)==1, inf>max, min==-max, true_min<min_positive,
true_min>0, nan!=nan).
- examples/0160: float-only accessor on an int (s32.epsilon/u8.inf/
s64.true_min) and any accessor on a non-numeric type compile-error
cleanly (exit 1, pinned stderr).
- type_resolver.test.zig: floatLimitFor bit-pattern + property tests for
f32/f64, isLimitField coverage, null for non-float/non-limit fields.
- specs.md Numeric Limits: float accessors + the min=-max / min_positive=
smallest-normal / epsilon=ULP-of-1.0 / true_min=smallest-subnormal
clarifications, with the mandatory FTZ/DAZ flush-to-zero caveat.
readme.md overview updated.
A protocol method signature omits the receiver; a bare `self` has no type, so
`protocol { … :: (self) … }` fails at parse with 'expected :'. Correct the three
member-exemption doc snippets (readme.md, specs.md, issues/0089) to the valid
signature form, matching examples/0158's `Speaker :: protocol { s2 :: () -> s64; }`.
The member-name exemption applies only to identifier-classified reserved
spellings (s1..s64, u1..u64, bool, string, void, usize, isize, Any). f32/f64
are lexer keywords (token.zig kw_f32/kw_f64) and member-name slots require an
identifier token, so a bare f32/f64 field/tag/method name is rejected at parse;
the backtick is required there too. specs.md + readme.md corrected.
AGRA RULING (issue 0089, attempt 7): bare reserved-name MEMBER positions are
intentionally exempt from the reserved-type-name rule, and the implementation
already does the right thing — this is a docs + one-example change, no code.
The exempt member positions are struct FIELD names, union TAG names, and protocol
method-SIGNATURE names: they sit in a member slot, are reached via obj.name (or
dispatched by string), and are never type-classified, so they never mis-lower.
The backtick is optional there. The exemption stops at member DEFINITIONS: an
impl method is a real function (reached through the impl_block -> fn_decl arm), so
a reserved-spelled impl method still needs the backtick, exactly like a free
function (cf. examples/1122) — and every bare reserved-name value binding /
declaration name still errors (0076 preserved).
- specs.md / readme.md: replace the "every binding site" / "any binding site"
overclaim with the precise rule — required positions (value bindings +
declaration names + impl method definitions) vs the exempt member-name
positions (field / tag / protocol signature; backtick optional).
- examples/0158-types-reserved-name-member-exempt.sx: pins the exempt behavior —
bare reserved-name struct fields + union tag read & written bare AND via
backtick, and a protocol with a bare reserved-name method dispatched through
the protocol (impl definition takes the backtick).
- issues/0089: document the member-name exemption in the RESOLVED banner + add
0158 to the regression list.
Gate: zig build, zig build test, bash tests/run_examples.sh — all green
(430 passed, 0 failed, 0 timed out).
Closes the remaining three F0.6 findings so the universal backtick raw
identifier holds in BOTH classifiers and at EVERY parser construction site.
1. Struct-body constants thread is_raw + name_span. The struct-body const
forms (untyped `` `s2 :: 5 `` and typed `` `s2 : T : v ``) built the
const_decl node without name_span/is_raw, so a backtick const was falsely
rejected and a bare reserved-name const caretted at 1:1. They now capture
both. Structural cure: `ast.ConstDecl`'s name_span + is_raw carry NO
default, so the compiler rejects any construction site that omits them
(mirrors checkBindingName's required `is_raw` arg). FnDecl keeps its
defaults — every parser fn_decl routes through parseFnDecl whose
`name_is_raw` is a required parameter (equivalent guarantee).
2. Raw identifier in TYPE position flows through the normal continuations.
parseTypeExpr no longer returns a terminal type_expr for a raw atom; the
raw flag rides the atom through the qualified-path / Closure / parameterized
continuations, so `` `s2(s64) ``, `` *`s2 ``, `` ?`s2 `` all parse.
ParameterizedTypeExpr carries is_raw; resolveParameterizedWithBindings
skips the `Vector` intrinsic when raw.
3. sema/LSP (the second classifier) honors is_raw. Type.fromTypeExpr returns
null for a raw type_expr; resolveTypeNode skips the builtin classifier when
raw; resolveTypeNameStr takes a skip_builtin arg threaded from te/id.is_raw
(compound inner names pass false). A backtick reserved-name annotation now
resolves to the user type in the editor index, not the builtin.
Tests: examples/0156 (struct-body const), 0157 (parameterized raw type +
wrappers), 1142 (bare struct-body const errors, caret on name); src/sema.test.zig
pins the LSP raw-type resolution (fail-before verified). Gate: 365 unit tests,
429 examples, 0 failed.
AGRA ruling (attempt 4): `` `name `` is THE LITERAL identifier `name`, usable in
EVERY position — the backtick only means "treat this token as a plain identifier,
never the reserved keyword/type", and is never part of the name's text.
- Raw in TYPE position is now VALID (reverses attempt-2 "raw is not a type"):
`parseTypeExpr` emits a raw `type_expr`; `TypeResolver.resolveNamed` gains a
`skip_builtin` flag (threaded from `te.is_raw` via lower.zig + type_bridge) so a
`` `s2 `` reference resolves to a `` `s2 ``-declared type (struct/enum/union/alias),
else a normal "unknown type 's2'" error (reportIfUnknownType skips the builtin
exemption when raw). Bare `s2` in type position stays the builtin int.
- Every declaration-name site is is_raw-exemptible: `is_raw` added to TypeExpr +
StructDecl/EnumDecl/UnionDecl/ErrorSetDecl/ProtocolDecl/ForeignClassDecl/UfcsAlias/
NamespaceDecl/ImportDecl/CImportDecl/LibraryDecl; parser threads name_is_raw to
every decl parse fn; namespace imports carry it through imports.addNamespace.
Typed-const path (`` `s2 : s64 : 5 ``) now threads name_span+is_raw (fixes the
1:1-caret bug).
- Check<->exemption made structurally symmetric: checkBindingName/checkDeclName take
is_raw as a REQUIRED argument and skip inside the check, so no call site can
validate a name without honoring the exemption (the desync cause of prior rounds).
- Bare reserved-name declarations of every kind still error (0076 preserved);
`#import c` foreign names stay auto-raw + bare-callable.
specs.md + readme.md updated to the universal model. issue 0089 RESOLVED banner
rewritten. Examples: replace 1139 (raw-not-a-type) with 0154 (raw type reference);
add 0155 (typed const + union tag) and 1141 (bare type-decl negatives).
Gate: zig build + zig build test + run_examples (426 passed, 0 failed).
A bare reserved-type-name `::` declaration was silently accepted, and the
attempt-2 lowerCall rewrite then made a bare `s2 :: (…) {…}` function callable —
bypassing the backtick rule for handwritten sx. The reserved-name binding check
covered `:=` / typed-local / param / captures but NOT the `::` declaration form.
- ast: `ConstDecl`/`FnDecl` carry `is_raw` + `name_span` threaded from the parser
(parseConstBinding / parseFnDecl, all call sites incl. struct/impl methods).
- semantic_diagnostics: reject a bare reserved spelling at EVERY declaration-name
site — const, function (incl. struct/impl methods), struct/enum/union/error-set,
protocol, foreign-class, ufcs alias, namespaced/library/c-import name. Backtick
(`is_raw`) and the compiler's `#builtin` definition (`string :: []u8 #builtin`)
are the only exemptions; a value whose node is itself a named decl defers to
that node's own check.
- c_import: synthesized foreign fn_decls are `is_raw = true`, so a C function
whose own name collides with a reserved spelling (`int s2(int);`) imports and
bare-calls unedited.
- lower: scope the `.type_expr`→`.identifier` call rewrite to a callee FnDecl of
RAW provenance (`is_raw`) — only a backtick / `#import c` foreign fn can carry a
reserved-name spelling, so a non-raw match never gets rewritten.
- examples: 0153 (positive — backtick `::` const + fn, bare + tick call), 1140
(negative — bare `::` const + fn rejected).
- docs: specs.md + readme.md state the backtick is required at every binding site
including `::` const / function / type declarations; issue 0089 banner updated.
Completes the issue-0089 backtick raw-identifier / `#import c` exemption
across all remaining identifier positions and closes three boundary gaps
the F0.6 review found.
1. Exhaustive raw-binding coverage. The `is_raw` bit now threads through
`ast.Identifier` and EVERY binding/capture form — `IfExpr`/`WhileExpr`
optional bindings, `ForExpr` capture + index, `MatchArm` capture,
`CatchExpr`/`OnFailStmt` tag bindings, `DestructureDecl` per-name, and
the protocol-default-body / foreign-class method param lists — not just
`var_decl`/`param`. `UnknownTypeChecker` skips the reserved-name check at
each arm when raw, so a backtick works in every identifier position while
a bare reserved spelling still errors (issue 0076 preserved).
2. Raw identifier is never a type. `parseTypeExpr`'s atom rejects a raw
identifier in type position (`x : `s2 = 1`, `List(`s2)`) with an accurate
diagnostic instead of silently type-classifying it.
3. Reserved-name function bare-callable. A bare `s2(4)` parses its callee as
a `.type_expr` (reserved spelling); `lowerCall` now rewrites a type_expr
callee to an identifier when a function of that name is in scope, so a
backtick-declared sx fn and a `#import c` foreign fn whose C name collides
with a reserved type spelling both resolve by their bare name.
(`TypeName(val)` is not a cast, so there is no ambiguity.)
Tests: examples/0152 (every control-flow/capture form + bare ref/call/member
access), examples/1054 (catch/onfail tag bindings), examples/1139 (raw in
type position rejected), examples/1220 extended (foreign reserved-name
function bare-call). 0076 negatives 1119/1121/1122/1123/1124/1125 stay green.
Gate: zig build + zig build test + 422 examples pass. specs.md + readme.md
updated; issues/0089 RESOLVED banner refreshed.
Reserved type-name spellings (s1, s2, u8, …) can now be used as value
identifiers two ways, resolving issue 0089:
1. Backtick raw identifier: a leading backtick (`s2) lexes to an
.identifier token carrying a new Token.is_raw flag, with the backtick
excluded from the text. A raw identifier is never type-classified — the
parser skips Type.fromName for it — so it is always a value identifier.
The flag threads to VarDecl.is_raw / Param.is_raw at binding sites, and
the reserved-type-name check (UnknownTypeChecker) skips raw bindings.
Because the token tag stays .identifier, the escape works in every
position (local, global, param, field, fn name, struct member, later
reference) with no per-site parser change.
2. #import c exemption: c_import.zig synthesizes foreign decls with
Param.is_raw = true, so generated C param names that collide with
reserved type names (s1, s2) import unedited.
A bare reserved-name binding in sx still errors (issue 0076 preserved):
the is_raw-gated skip only fires for backtick / foreign names, and a raw
binding's address-of / autoref lowering stays correct because every
occurrence is an .identifier, never a .type_expr.
Tests: examples/0151 (backtick, every position),
examples/1220 (foreign exemption, compiled+run), lexer unit tests.
1119 (bare-binding rejection) stays green. specs.md + readme.md updated.
emitCmpNe lowered float `!=` to `LLVMRealONE` (ordered not-equal), which
is false when either operand is NaN. That made `nan != nan` false in
native code — breaking the canonical `x != x` NaN test, making `!=`
non-complementary with `==` for NaN, and disagreeing with the interpreter.
Change the float predicate to `LLVMRealUNE` (unordered not-equal): true
if either operand is NaN OR they are unequal. For all non-NaN operands
`UNE` ≡ `ONE`, so only NaN-involving comparisons change (toward correct).
The integer predicate (`LLVMIntNE`) and `emitCmpEq` (`OEQ`) are unchanged,
so `nan == nan` stays false and `!=` is now the exact complement of `==`.
- Regression: examples/0150-types-float-ne-unordered-nan.sx (fails before,
passes after; also pins #run/comptime == runtime agreement).
- specs.md: documents float comparison / NaN semantics (Operators).
- Resolves issue 0091 (issues/0091-float-ne-ordered-nan.md).
A field-like access on a builtin INTEGER type name folds to a compile-time
constant of the queried type, driven by (width, signedness) arithmetic:
sN: min=-(2^(N-1)), max=2^(N-1)-1; uN: min=0, max=2^N-1
for every width s1..s64 / u1..u64 (not just power-of-two), plus usize/isize.
- type_resolver.zig: extract the single width parser (parseWidthInt) reused by
resolveNamed AND the new accessors (no second parser — issue-0083 class);
add resolveBuiltinName / integerWidthSign / integerLimitBits / integerLimitFor.
- lower.zig: lowerNumericLimit intercept beside the error.X / Struct.CONST /
pack-arity identifier-receiver intercepts; folds ints via constInt, emits a
clean diagnostic for a non-numeric receiver (bool/string/void/Any/noreturn),
falls through for floats (NL.2).
- expr_typer.zig: mirror the result type so inferExprType reports the queried type.
- program_index.zig: recognize the accessors in the comptime-int / array-dim path
so [u8.max]T (255) / [s16.max]T (32767) work; [u64.max]T is rejected oversized.
- u64.max / usize.max stored as the all-ones bit pattern with TYPE u64 (i64 -1),
asserted via union { u: u64; s: s64 } reinterpret.
Docs: specs.md numeric-limits subsection (formulas + result-type + u64 note);
readme.md language overview. Examples 0148 (positive) / 0149 (negative-receiver).
Unit tests for the value computation in type_resolver.test.zig.
Gate: zig build, zig build test (359/359), tests/run_examples.sh (416 ok, 0 failed).
The count description claimed every count must be "positive integral",
which is wrong: zero is context-dependent. Verified at HEAD — an array
dimension (`[0]s64`) and a generic value-param count (`Box(0)`, $N:u32)
both accept zero as a length-0 instantiation, while a `Vector` lane
count stays strictly positive (`Vector(0,f32)` rejected). Negatives are
rejected for array dims and unsigned value-params, but a signed
value-param accepts a negative; only the integral requirement (folds
4.0, rejects 4.5) is common to all three.
Split the count paragraph into per-consumer bullets stating the exact
range each accepts. Range-bound paragraph unchanged. Pin the zero
contrast with examples 0147 (array-dim + value-param zero accepted) and
1505 (Vector zero-lane rejected). No compiler-code change.
specs.md lumped `inline for` / `for` range bounds in with counts (array
dimension, Vector lane count, generic value-param count) under the
count negative-rejection rule. A range bound is a range ENDPOINT, not a
count: negative endpoints are valid and an empty/inverted range runs zero
iterations. The compiler already implements this correctly (Agra ruling:
spec-text bug, no code change).
- specs.md: counts and range bounds are now described separately. Counts
reject negatives; bounds accept any compile-time integer (negatives
valid, integral floats fold) but still reject a non-integral float
because the loop cursor must be an integer.
- examples/0612-comptime-inline-for-range-bounds.sx: `inline for -2..1`
and `for -2..1` both sum -3; `inline for 0..(-2.0)` runs zero
iterations (empty range). Runtime/comptime parity asserted.
- examples/1138-diagnostics-inline-for-non-integral-bound.sx: a
non-integral float bound `inline for 0..4.5` is a clean diagnostic,
exit 1 (must-be-integer still applies to bounds).
Count consumers (1132/1133/1134/1135) unchanged and green.
Item 2 (Agra ruling): a compile-time INTEGRAL float (`4.0`, `N : f64 :
4.0`, `N :: 4.0`) used as an array dimension / Vector lane / generic
value-param count / `inline for` bound now folds to its integer at the
shared leaf — `program_index.floatToIntExact`, used by both the
`.float_literal` arm of `evalConstIntExpr` and `moduleConstInt`. All four
consumers route through the one evaluator, so `[4.0]s64` lays out the same
`[4]s64` uniformly; a non-integral (`4.5`) or negative value stays
rejected by the downstream `foldDimU32` gate. Pass-0 now pre-registers
float-valued module consts for forward-alias parity with int consts.
Item 1: a generic value-param bind (`Box($K: u32)`) never range-checked
the folded arg, so `Box(5_000_000_000)` compiled and ran. The bind now
range-checks against the param's declared type — a `u32` count through the
shared `foldDimU32` gate (making program_index's "single u32 gate for
value-param counts" doc true), any other integer type through the new
`program_index.intTypeRange` — and emits a clean "value N does not fit in
u32 parameter K" otherwise. The declared type is threaded via a new
`TemplateParam.value_type`.
Regressions: examples 0145 (integral-float array dim), 1504 (Vector lane),
0611 (inline-for bound), 0209 (value-param integral-float), 1132
(non-integral float dim rejected), 1133 (negative float dim rejected),
1134 (oversized u32 value-param rejected) + program_index float-fold unit
tests. Gate: zig build, zig build test, 406/0 run_examples.
A block's value is now its last statement ONLY when that statement is a
trailing expression with no `;`. A trailing `;` discards the value,
leaving the block void. This makes value-vs-statement explicit and lets
the compiler reject "this block was supposed to produce a value".
Compiler:
- Parser records `Block.produces_value` (last stmt is a no-`;` trailing
expression) + `Block.discarded_semi` (the `;` that discarded a value),
via `expectSemicolonAfter`. A trailing expression before `}` may now
omit its `;` (previously a parse error). Match-arm and else-arm bodies
are built value-producing regardless of the arm `;` (arms are exempt —
the `;` is an arm terminator).
- Lowering: `lowerBlockValue` / the block-expr path / `inferExprType`
respect `produces_value`. A value-position block that discards its value
is a hard error (`lowerValueBody` for function bodies; the value-context
`.block` path for if/else branches, `catch` bodies, value bindings,
match arms). Pure-failable `-> !` bodies (value rides the error channel)
and a value-if whose branches are void are handled without false errors.
- `defer`/`onfail` cleanup bodies lower as statements (void), so a
trailing `;` there is fine.
Migration (behavior-preserving — output unchanged):
- stdlib + ~210 examples: dropped the trailing `;` on value-position last
expressions. `format` now ends with an explicit `#insert "return
result;"` (it relied on `#insert`-as-block-value, which `;` discards).
- Two `main :: () -> s32` examples that relied on the old silent
default-return got an explicit trailing `0`.
- Rejection snapshots 0412 / 1013 regenerated (their quoted source lines
lost a `;`); the diagnostics themselves are unchanged.
Docs/tests: specs.md "Block values" section; examples 0040 (rules) + 0041
(rejection); 3 parser unit tests. Filed issue 0066 (pre-existing
match-arm negated-literal phi-width quirk, surfaced not caused here).
Gates: zig build, zig build test, run_examples.sh -> 343 passed,
cross_compile.sh -> 7 passed (also refreshed its stale example names).
Add a top-level §12 Error Handling distilling the locked error design +
surface syntax: failable signatures (-> (T,!) / -> ! / multi-value),
named `error { }` + inferred `!` sets, raise/try/catch/or/onfail, the
path-marker rule, set widening, error.X as a value, discard rejection +
flow-check, closures-with-!, return traces, and the u32-last-slot ABI.
Renumber Grammar §12→§13 and Open Questions §13→§14 (insert sits after
§10.5, so §3/§10.5 — the only section numbers referenced from CLAUDE.md
— stay valid). Cross-link the `!` channel from the Keywords list,
Operator Precedence, Function Definition, and §11 Program Structure;
extend the §13 grammar with error_decl, raise_stmt, onfail_stmt, a
catch_expr tier, `try` in unary, and failable type productions.
Pure docs; no compiler change. Gates: build, test, run_examples (293/0).
The cursor clause now matches the collection form's ': (capture)' — 'for 0..N: (i)' instead of 'for 0..N (i)'. The colon is required when a cursor is present; the no-cursor form 'for 0..N { }' is unchanged. Updated examples/200, the pack-index doc comment, and the spec.
Using a bare pack name where a runtime value is required was silent garbage
(f(xs)/return xs produced a stray pointer). Now a clear, context-tailored
compile error: isPackName + diagPackAsValue, caught at lowerVarDecl (storage),
lowerReturn (return), lowerFor (iterate), and an identifier-arm catch-all for
call/other. Storage binds a placeholder so there is no cascade error.
Suggestions point at WORKING fixes -- materialize (..xs), or declare the slice
form ..xs: []P for runtime use. The plan category-B "spread ..xs" is broken
(spreading a comptime pack into a []Any param crashes the LLVM verifier; filed
issue 0053), so the diagnostics steer to the slice-of-protocol variadic instead.
Repurposed examples/162-pack-bare-args.sx (was an aspirational bare-$args->[]Any
auto-materialise, contradicting Decision 1) into the slice-form forward
(..args: []Any). examples/203 is the four-category negative test. specs.md "Pack
as value" updated. 238 examples + unit green.
packVariadicCallArgs stored the raw concrete arg into a [N x P] array when the
element type was a protocol, so an 8-byte struct landed in a 16-byte {ctx,
vtable} slot -> garbage vtable -> Bus error on dispatch. Now, when the slice
element type is a protocol, each arg is xx-erased to the protocol value via
buildProtocolErasure (same impl-driven machinery as the xx cast). This makes
..xs: []P the runtime, protocol-erased counterpart to the comptime
heterogeneous pack ..xs: P (which stays comptime-only): xs[runtime_i].method()
now works in an ordinary loop.
specs.md: full variadic/pack form-comparison table (concrete-vs-erased,
comptime-vs-runtime). Regression: examples/202. Issue 0052 (FIXED). 237 green.
Add range loop syntax:
- runtime for start..end (i) { } counting loop, cursor optional, end exclusive
- comptime inline for start..end (i) { } comptime-unrolled body
The inline form binds the cursor as an int_val comptime constant per
iteration, so xs[i] over a heterogeneous pack substitutes the concrete
per-position element -- the canonical's pack-iteration vehicle
(inline for 0..sources.len (i) { sources[i].addListener(...) }).
- AST: ForExpr.range_end, ForExpr.is_inline
- parser: parseForExpr range vs collection form; suppress_call flag so
N (i) is not read as a call N(i) while parsing a range bound
- lower: lowerRuntimeRangeFor / lowerInlineRangeFor; evalComptimeInt;
comptimeIndexOf extends pack-index resolution beyond int literals
Revises spec's inline for i in 0..N to the no-in, range-first, paren-cursor
form. Regression: examples/200-for-range.sx.
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.
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.
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.
`xx <struct-typed local>` used to heap-copy the value through context.allocator.
The protocol value's `ctx` pointed at the heap copy; the original local was
left behind, untouched. Mutations through the protocol never reached the
original, and direct reads of the original never saw protocol mutations.
Two-fork bug, silent, easy to write by mistake.
New rule (Option 3 in the discussion):
- `xx <lvalue>` — identifier, field access, index expression, deref —
borrows the operand's storage. No heap copy, no `free` needed.
- `xx <rvalue>` — struct literal, function-call result, arithmetic, etc. —
heap-copies through context.allocator. Unchanged from today.
- `xx @ptr` and `xx <pointer-typed value>` — borrows the pointee. Unchanged.
Single switch in `buildProtocolErasure` ([lower.zig:10334](src/ir/lower.zig#L10334))
gated by a new `isLvalueExpr` helper ([lower.zig:10322](src/ir/lower.zig#L10322)).
Struct-typed operand: if the AST shape is identifier/field/index/deref,
emit `lowerExprAsPtr(operand_node)` and skip the heap-copy; otherwise
keep the alloca-store-heap_copy path.
specs.md §3 ownership table extended to three rows (rvalue, lvalue,
pointer) with examples and rationale per row.
Regressions:
- `examples/130-xx-value-routes-through-context-allocator.sx` — the
Phase 1.1 witness for heap-copy-via-context-allocator. Previous shape
(`xx <local-value>`) is now a borrow under Option 3 and no longer
exercises the heap-copy path. Rewritten to use a struct literal
(`xx ByValue.{...}`) which still heap-copies through context.allocator
— Tracer.count = 1 as before.
- `examples/135-xx-lvalue-borrows.sx` — new test. Dereferences a
TrackingAllocator into a stack value, does `xx tracker` inside a
push Context, and asserts alloc_count/dealloc_count on the LOCAL go
up. Under old semantics this would have stayed at 0 (heap copy got
the increments, local stayed stale).
157/157 example tests pass; chess clean on macOS / iOS sim / Android
(`tools/verify-step.sh` ran green immediately before this work).
The chess panel-text regression (text vanished after the first move on
macOS) had a single root cause: GlyphCache's entries List, hash table,
and shaped_buf grew through `context.allocator` — which during render
is the per-frame arena. On the next arena reset the backing died, and
subsequent glyph lookups read garbage / wrote into freshly-allocated
view-tree memory.
Fix is shaped as the user proposed: `List(T)`'s mutations take an
optional trailing `alloc: Allocator = context.allocator` argument. No
allocator stored on the container, no init ceremony, every existing
`list.append(item)` callsite keeps working unchanged. Long-lived
owners now write `list.append(item, self.parent_allocator)` and the
arena-leak bug becomes impossible to write accidentally.
Default-arg substitution previously only fired for identifier callees
(`expandCallDefaults` at lower.zig:7978). Extended to the generic
struct-method dispatch path (`list.append(...)` lands here) via a new
`appendDefaultArgs` helper that lowers fd.params[i].default_expr in
the caller's scope and appends to the lowered args slice.
Long-lived owners updated to capture `parent_allocator: Allocator` at
init and use it for every internal growth:
- GlyphCache (the chess bug) — entries, shaped_buf, hash_keys,
hash_vals, atlas bitmap.
- DockInteraction — drops the existing `push Context` workaround in
`ensure_capacity` for the explicit-arg form.
- StateStore — entries list + per-entry data buffer.
- Gles3Gpu, MetalGPU — shaders, buffers, textures (atlas-grow during
render would otherwise leak resources into the frame arena).
Also kept: an operator-precedence fix in pipeline.sx
(`(self.frame_index & 1) == 0` instead of
`self.frame_index & 1 == 0`, which parses as
`self.frame_index & (1 == 0)` = always 0). That was a stealth
single-arena-only bug that masked the GlyphCache one for a long time.
Docs:
- specs.md §11 documents `param: T = expr` default parameter values.
The parser already supported it — formalised in the spec now.
- current/CHECKPOINT-MEM.md logs the change.
- CLAUDE.md REJECTED PATTERNS gains a "Long-lived containers growing
through context.allocator" section with the `parent_allocator`
capture template and the list of existing examples to mirror.
155/155 example tests pass — zero-diff against snapshots since every
existing callsite still resolves to `context.allocator`.
