The block-value rework routes value-position `{ … }` through the same
statement parser as every other block, so a destructure decl (and any
statement form) inside a value-bound block now parses, with the trailing
expression as the block's value. The `defer { … }` half was fixed
earlier (634cf9b). Regression: examples/0042-basic-block-value-destructure.sx.
Gates: zig build test, run_examples.sh -> 344 passed.
A braced `defer` body routed through `parseExpr` + a mandatory trailing
`;`, so it parsed the `{ … }` as a block-EXPRESSION whose statement loop
doesn't handle a destructure decl or a `catch`-statement — `defer { v, e
:= f(); … }` and `defer { x() catch e … }` failed with "expected ';'",
and even `defer { stmt; }` needed a spurious trailing semicolon.
Now the `kw_defer` arm parses a braced body with `parseBlock` (the same
path `onfail` uses), so every statement form works; the bare-expression
form (`defer expr;`) is unchanged. `in_defer_body` is still set before
parsing, so the cleanup-body control-flow bans (return/break/continue/
try/raise) and the E1.7 failable-absorption check still fire.
Resolves the `defer` manifestation of issue 0065 (the general
value-block-in-binding-position destructure remains open). Regression:
examples/1050-errors-defer-block-body.sx.
Gates: zig build, zig build test, run_examples.sh -> 341 passed, 0 failed.
A `defer`/`onfail` body runs while the block is already exiting, so a
failable call there has nowhere to propagate its error. The parser
already bans `try`/`raise`/`return`/`break`/`continue` in cleanup bodies
(f9dd965); this adds the remaining sema rule — a bare (un-absorbed)
failable call must be absorbed locally with `catch` or `or <value>`.
Implemented in the shared error-flow pass (`checkCleanupBody` /
`checkCleanupNode` / `cleanupReject` in ir/lower.zig): when the walk hits
a `defer`/`onfail`, it scans the body transitively (through blocks, `if`,
loops, match arms, `catch` handlers; stopping at nested closures) and
flags any still-failable expression. `catch` / `or value` strip the
error channel, so `exprIsFailable` is false for them — only an unhandled
failable trips the check. This completes ERR PLAN E0–E5 plus the two
deferred E1 follow-ups (E1.7 + E1.8).
New regressions: 1048 (catch/or-value absorbed forms compile + run) and
1049 (bare failable in defer and onfail rejected, exit 1).
Filed issue 0065: a braced `defer { … }` / value-block body routes
through `parseExpr` (not `parseBlock` like `onfail`), so it can't parse a
destructure or `catch`-statement inside. Orthogonal to E1.7 — the spec'd
cleanup absorbers (`catch` / `or value`) parse fine in a `defer` body.
Gates: zig build, zig build test, run_examples.sh -> 340 passed, 0 failed.
