convergeClosureShapeSets, checkErrorFlow, and the unknown-type loop ran
under whatever current_source_file the previous phase left behind —
closure-literal annotations resolved (and reject/unknown-type
diagnostics rendered) against an arbitrary module. Latent while std.sx
was a single file (the ambient happened to be the main file); the
re-export facade restructure exposed it. Each walk now pins
setCurrentSourceFile per decl / per fn (body.source_file is already
stamped by resolveImports). Coverage: examples 0129/1047/1049/1052/
1053/1056 against the facade std.sx. Gates: zbt 426/426, suite 588/588.
The for header is now a comma-separated list of iterables with a
positional capture group and no ':' separator:
for xs (x) { } // collection
for 0..n (i) { } // range (end exclusive)
for 1..=5 (a) { } // ..= inclusive end
for xs, 0.. (x, i) { } // index idiom (replaces (x, i))
for xs, ys (x, y) { } // parallel (zip) iteration
for xs (x) => sum += x; // arrow body (full statement)
First-iterable-wins: the first iterable's length drives the loop and
must be bounded; the other positions follow by their own cursors (a
non-first range's end is not consulted or evaluated; a shorter
non-first collection is read past its length on mismatch). The old
single-iterable index capture is replaced by the trailing open range.
Capture/call disambiguation is positional: the paren group immediately
before '{' or '=>' is the capture, every earlier top-level group is a
call. 'for zip(a, b) (x, y)' calls zip; 'for f(n) { }' reads (n) as
the capture and errors with a parenthesize/add-capture hint. The old
':' form errors with a migration hint.
Lowering is unified across forms: one cursor slot per position (ranges
start at their start, collections at 0), all advanced together, the
first position's bound terminating. inline for keeps the single
bounded comptime range.
Migrated the full corpus (examples, library modules, issue repros,
in-source test strings). New coverage: examples/0050 (the full feature
surface) and examples/1149-1155 (seven diagnostic faces). specs.md For
Loop section + grammar rewritten; readme teaser updated.
Move the diagnostic-only Pass 1e (ERR E1.7 cleanup-absorption + E1.8 value-slot
liveness) out of lower.zig into src/ir/error_flow.zig behind an ErrorFlow
*Lowering facade (Principle 5, like ErrorAnalysis/CoercionResolver). Behavior
preserved exactly — pure relocation.
Moved verbatim (self. -> self.l. for Lowering members; sibling calls stay on the
facade; provenHas is a file-local free fn): checkErrorFlow, analyzeFnBody,
flowWalk, flowStmt, flowIf, flowMatch, flowExpr, applyRefinement,
provenAdd/provenClone/provenIntersect, registerFailableDestructure,
checkCleanupBody/checkCleanupNode/cleanupReject, plus the FlowCtx/ProvenSet types.
- lowerRoot routes the single call site through
self.errorFlow().checkErrorFlow(decls); no Lowering wrapper kept (only the
pipeline calls it, no unit-test caller). New errorFlow() accessor.
- The pass takes AST decls + ProgramIndex + diagnostics only — independent of IR
Builder state (PLAN-ARCH A5.2 success criterion).
- New pub: exprIsFailable (only widening; inferExprType/errorChannelOf already
pub). lower.zig -389 (->17030); error_flow.zig 407. Barrel-wired in ir.zig.
- No .test.zig: diagnostic-pass altitude (functions return only bool + emit
diagnostics) — guarded by example anchors 1046-1053 (incl. scaffolding
1051/1052/1053). Phase A5 complete.
Gate: zig build, zig build test, bash tests/run_examples.sh -> 361/0
(anchors 1046-1053 all ok, no .ir churn).
