CallPlan collapsed two different field-access dispatches onto namespace_fn:
a true namespace call (`pkg.fn()`, no receiver) and free-function UFCS
(`c.bump()`, receiver prepended + `*T` fixup). Return typing was preserved
either way, but sub-step 3 could not consume the plan — it would have had to
re-classify the AST to decide whether to prepend the receiver.
Add a distinct `free_fn_ufcs` kind and a plan(c) branch, inserted after the
struct-method block and gated on `objectIsValue` (the negation of lowerCall's
`is_namespace`: a non-identifier receiver is always a value; an
identifier/type_expr is a value iff it names a local or a global). The branch
sets prepends_receiver = true and reads prepends_ctx from the resolved FuncId
(best-effort, like direct_fn). namespace_fn now means strictly "receiver is a
namespace/type prefix".
New test `plan: free-function UFCS prepends receiver, distinct from
namespace_fn` covers a scope-bound `c.bump()` against a lowered free fn:
asserts free_fn_ufcs kind, func target, prepends_receiver, prepends_ctx, and
preserved s32 return type.
zig build, zig build test, tests/run_examples.sh (357/0) all green; return
typing unchanged.
Introduce CallPlan — the single classification record for a call: kind (14
variants), return_type, a Target union (builtin/func/named/protocol_method/
foreign_method/constructed/none), variant tag, and the prepends_receiver /
prepends_ctx / expands_defaults properties the selected dispatch implies.
Move call recognition into CallResolver.plan(c) (branch order preserved
exactly) and reimplement resultType(c) as plan(c).return_type — the typing
consumer converges onto the plan first. lowerCall is untouched; routing it
through plan(c) is sub-step 3.
10 plan-object tests assert kind/target/variant + receiver/ctx/default
properties for every pinned call form: builtin/reflection, lazy + resolved
direct fn (incl. default-arg expansion + __sx_ctx prepend), closure /
default-conv vs C-conv fn-pointer, protocol dispatch, struct/UFCS #compiler
method, foreign instance vs static, qualified + dot-shorthand enum
construction, namespace fn, and the unresolved fallthrough.
Widen for the new collaborator only: resolveVariantIndex -> pub (plan resolves
the variant tag); Scope/Binding + init/deinit/put -> pub (so unit tests can
stand up a lexical scope for closure/fn-ptr callees without a full lowering).
zig build, zig build test, and tests/run_examples.sh (357/0) all green; no
behavior change.
Move call-result-type discovery out of Lowering into a new src/ir/calls.zig
(CallResolver): the A3.1 Lowering.inferCallType body moves verbatim into
CallResolver.resultType. inferExprType's `.call` arm now delegates via
callResolver(); Lowering.inferCallType is gone.
CallResolver is a *Lowering facade (Principle 5, like ExprTyper/PackResolver):
call typing reads live lexical-scope / target-type state and the function /
foreign-class / protocol resolver helpers, so it borrows *Lowering. Transform
was `self.` -> `self.l.` plus the file-local static `resolveBuiltin(` ->
`Lowering.resolveBuiltin(`.
Widened to pub only what the facade actually consumes: resolveTypeArg,
inferGenericReturnType, resolveFuncByName, getProtocolInfo,
resolveForeignMethodReturnType, the static resolveBuiltin, and Scope.lookupFn.
resolveTypeArg widening is genuinely required here — the `cast` builtin's
result type calls it.
calls.test.zig adds focused tests (builtin/reflection classification, unknown
callee -> unresolved) for the scope-free paths. Barrel-wired in ir.zig.
This is the relocation half of PLAN-ARCH A3.2; call LOWERING (lowerCall) still
owns its own dispatch, and the CallPlan convergence (one plan shared by typing
and lowering, deleting the duplicated qualified/bare/lazy logic) remains.
Behavior-preserving. Gate: zig build, zig build test (incl. new CallResolver
tests), bash tests/run_examples.sh -> 356/0. lower.zig 18598 -> 18413.
