`raise EXPR` now terminates a failable function via the error channel.
Scope (Option 2): full raise sema checks + lowering for the pure-failable
shape (`-> !` / `-> !Named`); the value-carrying `-> (T..., !)` shape bails
loudly, deferred to E2's error-channel tuple ABI.
- lowerStmt + tryLowerAsExpr: `.raise_stmt` -> lowerRaise (also routes a
raise that is a block's last statement, which previously hit unknown_expr)
- lowerRaise: failable-context check (effectiveReturnType + errorChannelOf);
literal membership via lowerErrorTagLiteral; variable form subset-checked
via checkErrorSetSubset; pure-failable emits ret(tag)
- lowerErrorTagLiteral skips membership for the bare-`!` inferred placeholder
- plain `return;` in a pure-failable fn emits ret(0) (success / no error)
- parser: in_defer_body flag rejects `raise` inside a `defer` body
Tests: examples/219-raise.sx (positive, exit 8),
examples/220-raise-rejections.sx (3 sema rejections, exit 1), inline parser
test for raise-in-defer. Gates: zig build, zig build test, 258/258 examples.
Adds the `.error_type_expr` arm to type_bridge.resolveAstType (the gating site
that still returned `.unresolved`):
- `!Named` → resolveTypeName(name) → the declared error set (E1.1).
- bare `!` → a shared inferred placeholder error set (reserved name "!", empty
tags), refined per failable function by the E1.4 SCC pass.
The error channel then falls out of the existing multi-return + tuple
machinery: `-> (s32, !Named)` is a tuple_type_expr whose last field is the
error_type_expr → resolves to a tuple {s32, error_set} — exactly the locked
ABI (error slot = last return slot, u32). `-> !Named` resolves to the set.
Verified end-to-end via scratch: `parse :: (n) -> (s32, !ParseErr) { ...;
return (n, e); }` compiles + runs, `v, err := parse(5)` destructures (err typed
as the error set), `err == error.X` works; `-> !Named` single return too.
3 unit tests in type_bridge.test.zig (!Named, bare ! placeholder, tuple ending
in the error set). No examples/ — the only current usage path (return
(value, error)) will be flow-check-rejected at E1.8; the blessed example waits
for E1.3 (raise) + try/catch consumption.
zig build, zig build test (275), and 256/256 examples green.
Completes E1.1. All in ir/lower.zig (the IR layer, per slice 1's finding).
- lowerFieldAccess intercepts `error.X` (parsed as field_access(identifier
"error", X)) → lowerErrorTagLiteral: interns the tag; when target_type is a
named error set, types the value as that set and validates X ∈ set (out-of-set
→ diagnostic); otherwise emits the raw u32 global tag id (the spec's
context-free default — not a silent guess).
- tryLowerErrorSetEquality (early branch in lowerBinaryOp) + errorSetTypeOf /
isErrorTagLiteralNode: an error-set value or `error.X` literal forces the other
operand to be one too, else a diagnostic ("compares only with an error.X tag or
another error-set value; coerce with `xx`"). Both sides lower under the set type
as context (error.X resolves + membership-checks); two bare tag literals with no
context compare as global u32 ids. Handles both operand orders.
First ERR examples (end-to-end): 217-error-sets.sx (declared set + error.X +
== true/false + u32 coercion → "error-set result: 25", exit 25) and
218-error-set-typing.sx (out-of-set literal + tag-vs-raw-int → 2 diagnostics).
Failable `!`/`!Named` signatures and raise/try/catch/onfail semantics remain
(E1.2+). zig build, zig build test, and 256/256 examples green.
First sema/types step. Implemented in the IR layer (ir/types.zig +
type_bridge.zig + lower.zig), NOT src/sema.zig — lowering doesn't consume
sema; the frontend Type is LSP-only. Mirrors how enums are handled.
- ir/types.zig: new `.error_set` TypeInfo kind (ErrorSetInfo {name, tags:
[]u32}; identity = name, like enum) with a u32 runtime layout (size/align
4, LLVM i32) per the locked error-slot ABI. New TagRegistry on TypeTable
(global tag pool: name -> u32, monotonic, id 0 reserved for "no error").
internTag/getTagName/errorSetType helpers; `.error_set` arms in all 7
exhaustive switches + findByName.
- emit_llvm: toLLVMTypeInfo -> i32. print: writeType -> set name.
- type_bridge: resolveInlineErrorSet (mirrors resolveInlineUnion) +
.error_set_decl arm.
- lower.zig: registerErrorSetDecl (rejects empty `error { }` with a
diagnostic) wired into both top-level decl switches + the block-local one.
- tests: ir/types.test (TagRegistry 0-reserved + identity; errorSetType u32
layout + named display + dedup; sorted storage) and ir/type_bridge.test
(decl -> type + tag interning + re-resolve dedup).
End-to-end: `Foo :: error { A, B }` + main compiles + runs (exit 0) — first
ERR syntax to survive the full pipeline; empty set rejects with a diagnostic.
Inferred bare `!`, error.X value, and == typing deferred to slice 2 / E1.2.
zig build, zig build test, and 254/254 examples green.
Fills the E0.3 coverage gaps E0.1/E0.2's inline tests hadn't hit and adds
an end-to-end integration parse. Test-only; no production code change.
- `try` in statement position (`try must_init();`).
- `try` over a parenthesized or-chain (`try (foo() or boo())`) — distinct
from `try foo() or try boo()`.
- `or` value-terminator (`parse(s) or 0`).
- Integration: a full `parse :: (s) -> (s32, !ParseErr) { onfail / try / or /
catch / if { raise } / return }` — asserts the trailing `!ParseErr`, the
five body statement kinds, and that `in_onfail_body` is correctly scoped
(the later if-block `raise` is allowed).
Tests stay inline in parser.zig (consistent with the existing 24 + E0.1/E0.2
inline tests). 37 ERR parser tests total; every new AST node has a round-trip
test. zig build test (268) and 254/254 examples green.
Parser-only second step of the error-handling stream. No sema/codegen.
- token: 4 keywords — `raise`, `try`, `catch`, `onfail`.
- ast: RaiseStmt, TryExpr, CatchExpr {operand, binding?, body, is_match_body},
OnFailStmt {binding?, body}.
- parser:
- `try` is a unary prefix (binds tighter than `or`; right-recursive so it
stacks under `xx`/`@`/etc).
- `or` is already left-associative (precedence-climbing loop) — no change.
- `catch` is a postfix with four body shapes (no-binding block / block /
bare-expr / `== { case }` match-body, the latter reusing parseMatchBody
with the binding as subject).
- `raise EXPR;` and `onfail [e] { } | onfail EXPR;` statements; `error`
parses in expression position so `raise error.X` works; raise rejected
in expression position and inside an onfail body (in_onfail_body flag).
- consumer-aware `|>`: pipes the LHS into the head call through a
try/catch/or wrapper, preserving the wrapper.
- print: printExpr + match-arm printing for round-trips (anyerror!void to
break the printExpr<->printMatchArms inferred-error-set loop).
- sema/lsp: exhaustive switch arms for the 4 nodes + 4 keyword tokens.
- tests: ~22 inline parser tests (precedence, all catch forms, both
rejections, pipe cases, round-trip prints incl. match-body).
zig build, zig build test (264), and 254/254 examples green.
Reuse the compiler's lowering pass instead of re-implementing its checks
in sema. A module can't be lowered standalone — lowering only type-checks
functions reachable from a root — so the open file alone misses errors
like a *Move passed into a by-value method parameter. Drive the workspace
entry (main.sx) through parse → resolveImports → lowerToIR, then attribute
each diagnostic back to its file via source_file and publish per file
(clearing files whose errors are gone).
Runs on didOpen/didSave (disk-based); sema stays the live per-keystroke
layer. Advertise textDocumentSync.save so the editor sends didSave.
collectProjectDiagnostics is split out (transport-free) and covered by a
hermetic temp-project test.
Bring the lower.zig call-argument check to the LSP analyzer so the
`*T`-where-`T` mismatch (a `for xs: (*m)` capture or a `*T` parameter
forwarded into a by-value parameter) is reported inline as you type,
not only at build time.
The fn-signature registry resolved parameter types with the shallow
Type.fromTypeExpr, which yields 'unresolved' for user structs, so the
argument type never matched the parameter. Resolve params through the
registry-aware fieldType instead (as the param symbols already do).
Restricted to direct identifier calls so args align 1:1 with params.
Add a regression test.
The check only caught `for xs: (*m)` loop captures; passing a `*T`
parameter or any pointer local where `T` is expected still slipped through
to the LLVM verifier. Key the diagnostic on the lowered argument's type
instead of the capture, so a `*Move` parameter forwarded into a by-value
parameter is reported the same way. Ref-capture wording is preserved.
Add example 216 (pointer-parameter case) alongside 215 (loop capture).
`for xs: (*m)` binds `m` to a `*T`. Passing it directly to a parameter
that wants `T` produced invalid IR that only LLVM's verifier caught, with
the opaque 'Call parameter type does not match function signature'. Detect
it at the call site and emit a clear error with a fix-it suggesting `m.*`.
Add example 215 + expected output as a regression test.
Cmd+clicking a struct field / method / enum-variant at its own
declaration returned null, so nothing happened — while find-references on
the same token worked. Resolve a definition-site click to its own
location; the editor then surfaces references on a definition-click
instead of doing nothing. Member uses still resolve to their definition.
Add selfMemberDefAt + a regression test.
find-references only searched documents the editor had open, so asking
for references to a field from a file whose users were all closed
returned just the definition. Load every .sx under the workspace root
before matching so uses in unopened files are found too.
The LSP server's own tests were dormant: nested under the `lsp` struct in
root.zig, refAllDecls never reached them, and they had bit-rotted (stale
DocumentStore.init arity, an unaligned dummy io, fake /test/ paths that
no longer resolve). Reference the lsp files directly so their tests run,
give the doc-store tests a real Threaded io with bare paths, and fix the
stale extractIdentAtOffset expectation.
Extract referencesPayload from the transport so it is unit-testable, and
add tests covering cross-document field references, includeDeclaration,
the for-loop capture inlay hint, and workspace file loading.
The sema analyzer bound a for-loop capture with no type, so navigating
or hinting through it (m.flag, m: Move) failed. Instantiate generic
field types (legal_moves: List(Move)) and infer the capture's element
type from the iterable — List-like structs, slices, arrays, many-
pointers, and a pointer followed to its pointee. By-ref captures bind a
pointer to the element; range cursors bind s64.
Inlay hints now descend into struct method bodies and emit a type label
for the capture itself.
Now that 'context' resolves as an implicit global, accessing it inside a callconv(.c) function (an FFI callback/trampoline) would silently resolve — but the C ABI carries no implicit context parameter, so it's actually unavailable there. Sema now tracks the current function's calling convention and, for 'context' under callconv(.c), emits a specific diagnostic ('unavailable in a callconv(.c) function — pass what you need explicitly') instead of resolving it or saying 'undefined variable'.
context (the context system — context.allocator, context.data) was reported as an 'undefined variable'. It's now registered as a Context-typed global when Context is in scope, so the field chain (context.allocator) resolves too, with a builtins-list fallback when Context isn't present.
Members aren't symbols, so their uses were never recorded. Adds a member-reference list (declaration + uses) tracked during analysis: struct fields/methods and enum variants as declarations; field access, method calls, bare enum literals, qualified Type.variant, and match-arm patterns as uses. Spans are derived from the source-relative name slices; uses carry the owner type (via inferExprType, dereferencing pointers). find-references matches by (owner, name) across loaded documents, treating an unknown owner as a wildcard.
Verified: references for a field (legal_moves), a method (clear_valid_targets), and a variant (promote_rook — decl + comparisons + case patterns + struct-literal values across 5 files).
analyzeTopLevelDecl skipped struct_decl entirely, so identifiers used inside method bodies were never recorded as references — find-references (and reference-based features) missed method callers. Each method body is now analysed in its own scope. Verified: references to generate_legal_moves now include game.sx's call inside update_valid_targets.
cmd-clicking a definition (or any use) now lists all references. Same-file matches are precise (by symbol index); cross-file matches a top-level name across loaded documents. Advertises referencesProvider. Verified: references to a free function resolve across files (rules.sx def + internal calls + main.sx caller).
resolveStructTypeName returned null unless the variable's type was exactly a struct, so 'board.castling' (board: *Board) couldn't locate the Board declaration. It now also returns the pointee struct name for a pointer-to-struct, read from the resolved symbol type. Verified: board.castling navigates to board.sx's castling field.
Two gaps made 'piece := board.squares[move.from.index]' (board: *Board) <unresolved>: analyzeParams typed params with fromTypeExpr (bare-name only), so *Board / []T / *List params became null; and field_access only handled a struct value, not a *Struct. Params now resolve via fieldType, and field_access auto-derefs a pointer object (p.field on *T resolves on T). Regression test added.
The collection for-loop now iterates a List(T)-like struct ({ items: [*]T, len, … }) — and a *List — by viewing it as items[0..len]. So 'for legal: (m)' / 'for pieces: (*p)' work like iterating a slice, with by-ref captures writing back into the backing.
fixupMethodReceiver also derefs a *T receiver when the method takes T by value, so a 'for xs: (*x)' capture can call value-self methods (x.method()). Regression: examples/for-list.sx.
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.
event_position and translate_sdl_event matched on e.* / sdl.*; lowerMatch now auto-derefs a pointer subject, so 'if e ==' / 'if sdl ==' are equivalent (same load + tag-switch in IR). Pure cleanup.
KeyData.key was a raw u32 carrying SDL_Keycode values, so app code had to reinterpret it as SDL_Keycode (xx e.key) — a leaky, unchecked cross-platform cast only valid because the backend happened to be SDL. Add a neutral Keycode enum; translate_sdl_event maps SDL_Keycode to it via keycode_from_sdl. App code compares e.key == .escape with no platform type and no cast; a new backend maps its own native codes in one place.
(*x) binds x to a pointer into the collection (index_gep) instead of a per-element value copy: passing it on (e.g. to a *T param) is zero-copy and mutations write back. In a value position x auto-derefs — a binary-op operand loads the element, a pointer-typed slot keeps the pointer, and an 'if x == {...}' match derefs the pointee for its tag/payload. Arrays GEP through their storage so writes hit the original. Regression test: examples/for-by-ref-capture.sx.
ev := events.ptr[i] (events := g_plat.poll_events()) was <unresolved> through three gaps:
1. Return types went through Type.fromTypeExpr, which only handles a bare type_expr — so any []T / *T / List(T) return became void. An impl method 'poll_events -> []Event' registered as void and, merged after the protocol's correct signature, clobbered it. resolveReturnType now uses fieldType.
2. Struct/protocol methods were never put in fn_signatures, so recv.method() and Type.static() return types never resolved. registerMethodSig now adds them by bare name (first-wins), which is what resolveCalleeName already assumed.
3. .ptr/.len field access was string-only (and string.ptr wrongly returned string_type); now handles slices/arrays and returns the proper many-pointer element.
4. Tagged enums (payload variants) were only a symbol, never in a lookup registry; now also recorded in enum_types so the name resolves as a type.
Net: events -> []Event, events.ptr -> [*]Event, ev -> Event. Regression test added; confirmed end-to-end via the LSP inlay hint.
Add LANG (already had files in current/ but missing from the workstream
list) and ERR (new error-handling design, plan + checkpoint in current/
PLAN-ERR.md and CHECKPOINT-ERR.md — gitignored).
Updates the "On every session start" enumeration, the per-step
checkpoint-update guidance, and the File roles table to reference all
five streams.
Covers List(Move).items[i] -> Move via the LSP's flat-import struct_types merge (pre-registered, not self-declared) and with realistic methods/cross-referencing fields. Confirmed end-to-end against the real binary: the inlay hint for 'm := legal.items[i]' now resolves to Move.
inferExprType returned <unresolved> for 'legal.items[i]' (a List(Move) indexed) for two reasons: index_expr only handled string/array — not many-pointers/slices — and generic instantiation was dropped (List(Move) tracked as bare List, so T never bound to Move).
Fixes: (1) fieldType preserves pointer/slice element names (the old Type.fromTypeExpr only handled plain type_expr nodes, so [*]T became unresolved); (2) index_expr/slice_expr resolve many-pointer + slice elements via a registry-aware resolveTypeNameStr that knows user structs/enums (unlike Type.fromName); (3) instantiateGeneric monomorphizes List(Move) into a struct_types entry with T->Move substituted. So legal.items -> [*]Move and m -> Move. Regression test added.
ns_string's only caller was impl Into(*NSString) for string, so +stringWithUTF8String: is inlined there. c_string's one use (NSBundle.resourcePath in uikit) becomes rsrc.UTF8String() with resourcePath retyped *NSString. ffi-objc-call-06 and ffi-objc-dsl-07 .ir snapshots regenerated — they only drop the now-absent extern declares.
NSLog's fmt, addObserver's name, UIApplicationMain's principal-class, CADisplayLink's run-loop mode, and metal's newLibraryWithSource/newFunctionWithName string args are retyped *NSString, so their call sites read xx "..." instead of ns_string("...".ptr). ns_string is now used only by impl Into(*NSString) for string.
Adds an NSString foreign class and impl Into(*NSString) for string so a string literal flows into any *NSString slot via xx. uikit's keyboard userInfo lookups now read objectForKey(xx "...") instead of ns_string("...".ptr), and objectForKey's key param is retyped *NSString.
ffi-objc-call-06 .ir snapshot regenerated: declaring the NSString type adds its reflection thunks (struct_to_string/pointer_to_string), same as the existing NSObject/NSDictionary. Runtime output unchanged.
Impl blocks are anonymous (no declName), so a parameterised-protocol impl in a module reached via a diamond import was appended once per path and registered twice — 'duplicate impl Into for source s64'. mergeFlat and the directory-import merge loop now also dedup by node pointer; a physical AST node is lowered once regardless of how many import paths reach it.
Regression: examples/issue-0056-diamond-param-impl.sx.
The arithmetic-only check from the previous commit shared a hole with the
comparison and bitwise/shift ops: lowerBinaryOp derives the result type
from the LHS, so `s64 < string` fed mismatched types to `icmp` (LLVM
verifier failure) and `s64 & string` reinterpreted the string's bytes.
Add isOrderingOperand (numeric / enum / pointer / bool / vector) and
isBitwiseOperand (integer / enum / bool / vector), and route `< <= > >=`
and `& | ^ << >>` through them alongside the existing arithmetic check, all
sharing one diagnostic + placeholder-sentinel path. Flags-enum bitwise
(`.read | .write`, `perm & .read`), enum/pointer comparison, and int
literals stay legal (50-smoke unaffected).
Equality `== / !=` is deliberately left unchecked — its path is heavily
special-cased (str_eq, Any unbox, optional == null); folding a check in
without regressing those is a separate change, noted in the issue.
Regression test renamed arith→binop and broadened to cover `+ * < & <<`
against a string operand: examples/214-binop-operand-type-check.sx.
lowerBinaryOp derived the result type from the LHS alone and emitted
add/sub/mul/div/mod without checking the RHS, so `s64 + string` lowered
as `add : s64` and reinterpreted the string's bytes — printing garbage
instead of erroring.
Add isArithOperand (int / float / vector / pointer, plus custom int
widths) and, for `+ - * / %`, diagnose `cannot apply '<op>' to operands
of type '<lhs>' and '<rhs>'` and return a placeholder sentinel instead of
the corrupting op. `.unresolved` operands pass through so a type we
couldn't infer is never falsely rejected; the existing optional-unwrap
and int×float promotion are accounted for before the check.
Ordering (`< <= > >=`) and bitwise/shift (`& | ^ << >>`) ops share the
same LHS-derived-type hole and are left as a noted follow-up in the issue.
Regression: examples/214-arith-operand-type-check.sx (s64 + string, and
non-numeric LHS string * s64).
The full canonical `map` now compiles and runs (examples/213 → 42):
map :: (mapper: Closure(..sources.T) -> $R, ..sources: VL) -> VL($R)
Final piece: infer a pack-fn's generic return `$R` from a closure-typed
prefix param's lowered return type.
- collectGenericNames descends into closure_type_expr (params + return),
so `$R` in `Closure(..) -> $R` registers as a function type-param.
- matchTypeParam/extractTypeParam descend into closures: `$R` is extracted
from the lowered mapper's closure `.ret`.
- lowerPackFnCall infers type-param bindings from the lowered prefix args,
folds them into the mangle, and threads them into monomorphizePackFn,
which installs self.type_bindings for return-type resolution + body
lowering (`-> VL($R)` ⇒ VL(s64); `Combined($R, ..)` ⇒ Combined(s64, ..)).
s64-elimination follow-through:
- An unbound generic `$R` resolves to `.unresolved` in resolveTypeWithBindings
rather than fabricating an empty-struct stub (`R{}`).
- Lambda return-type inference skips an `.unresolved` target-closure ret and
infers from the body, so the concrete return drives `$R`.
- The `.unresolved` codegen tripwire then caught a latent bug: a generic-struct
source impl (`impl VL($R) for Combined($R, ..$Ts)`) was declaring its template
method `Combined.get` (`-> $R`) as a standalone IR function. Fixed: a
generic-struct source registers methods as TEMPLATES only (findable in
fn_ast_map for per-instance monomorphization via createProtocolThunk), never
declareFunction'd.
Feature 1 (heterogeneous variadic packs) all six phases complete.
248 examples + all unit tests green.
Two fixes, root-caused from xx Combined -> VL(s64) trapping:
- instantiateGenericStruct binds the template name to the concrete instance
(tb.put(tmpl.name, id)), so an impl method self: *Combined resolves self.field
to the instance (Combined__s64_s64), not the 0-field generic stub. This was a
general pre-existing bug: self.x on ANY generic-struct impl method failed.
- createProtocolThunk monomorphizes the template method for a generic-struct
instance (Combined.get -> Combined__s64_s64.get with the instance bindings),
so the erasure vtable dispatches instead of hitting an unreachable thunk.
xx c on a generic Combined now dispatches correctly (examples/212 -> 99).
247 examples + unit green.
lowerPackFnCall lowered the runtime prefix args with no target_type, so a
lambda arg (mapper: Closure(...) -> ...) could not infer its param types.
Now set target_type to the param type while lowering each prefix arg. With
the existing value-projection call-arg spread, mapper(..sources.get) works:
the lambda is contextually typed and the projected values spread into the
call. examples/211 ((a,b)=>a+b over two sources -> 42). 246 + unit green.
lowerTupleLiteral now coerces/erases each spliced spread element to the
contextual target tuple field type (computed even when a spread is present,
indexed by output position). New coerceOrErase: protocol target -> xx-erase
via buildProtocolErasure, else coerceToType. So c.sources = (..sources) on a
(..VL(Ts)) field erases each concrete pack element to its VL(Ti) slot.
examples/210 (build(IntCell, StrCell) -> 10 hi). 245 examples + unit green.
Parser now accepts a `..` spread in a parameterized-type arg list; in
instantiateGenericStruct a spread arg bound to the variadic type-param expands
via packTypeElems (so `..sources.T` projects each source pack element protocol
type-arg into ..$Ts). `Combined(s64, ..sources.T)` for a VL(s64) source
instantiates Combined(s64, s64). examples/209 (with explicit per-element xx
erase). 244 examples + unit green.
Next: (..sources) whole-pack materialization with per-element erasure into the
protocol-typed field (c.sources = (..sources) currently segfaults).
Two fixes:
- Element assignment `t.0 = v` (the known Phase-4.2 gap): the lvalue path
looked the element up by NAME via getStructFields, never matched a tuple
(positional), and left field_ty .unresolved -> ptr(.unresolved) -> codegen
panic. Added a tuple branch to the field-assignment lowering that indexes by
position (numeric) or name (tup.names), mirroring the read path. Fixes
`c.sources.0 = v` on a generic-instance pack field too.
- Named tuples: the parser dropped captured field names for a tuple TYPE
`(x: T, y: U)` (passed field_names=null), and resolveTupleTypeWithBindings
also nulled them. Both now preserve names (synthesizing _<i> for any unnamed
slot), so `t.x` reads/writes by name and `.0` by position.
examples/208. 243 examples + unit green.
packTypeElems now handles a parameterized spread operand F(Ts): for each pack
element T_i it temporarily binds the pack name to T_i and resolves F(T_i),
yielding (VL(T0), VL(T1), ...). Combined with parameterized-protocol value
types, the canonical Combined struct field sources: (..VL(Ts)) now resolves to
a tuple of real protocol values.
End-to-end (examples/207): instantiate Combined(s64, s64, string), whole-store
c.sources = (xx IntCell, xx StrCell), and per-element dispatch c.sources.0.get()
/ c.sources.1.get() all work. 242 examples + unit green.
VL(s64) used as a value/field type resolved to a 0-field stub (size 0); a
plain protocol was already a 16-byte {ctx,vtable} value. New
instantiateParamProtocol materializes a parameterized protocol per
instantiation: a 16-byte protocol value (is_protocol), protocol_decl_map
methods resolved under the type-arg binding (get -> T becomes get -> s64 for
VL(s64)), a vtable struct, and the type-arg binding recorded for projection.
Hooked into resolveParameterizedWithBindings before the empty-struct fallback.
xx-erasing a conforming struct into VL(s64)/VL(string) + method dispatch now
works (examples/206). This is the keystone for the canonical Combined field
(..VL(Ts)). 241 examples + unit green.
