Surface rename of the signed integer family: s1..s64 become i1..i64
(u1..u64, usize, isize unchanged). 'string' keeps the s-prefix arm in
name classification; width parsing moves to the i-prefix arm next to
isize.
Internal TypeId tags follow the surface (.s8/.s16/.s32/.s64 ->
.i8/.i16/.i32/.i64), as do mono-key mangle fragments (ptr_i64,
tu_i64_bool) and all display/diagnostic formatting (i{d}).
Migrated in the same sweep: stdlib + examples + issue repros + FFI C
companions (shared symbol names like ffi_id_i64), expected
stdout/stderr/ir snapshots, specs.md, readme.md, CLAUDE.md/AGENTS.md,
implementation_plan.md, docs/, issue writeups. Vendored stb_image and
historical flow state left untouched.
zig build test: 426/426; examples suite: 595/595.
A closure's underlying function carries a hidden env arg that a bare (T)->U slot
doesn't pass, so a closure flowing into a bare function-type slot dropped the
env — the first user arg landed in the env slot and the rest read garbage
(apply(closure((x)->s64 { x*2 })) returned 192 instead of 10; non-failable too).
- createClosureToBareFnAdapter: a capture-free closure into a bare (T)->U slot is
bridged by a generated adapter carrying the bare ABI (forwards a null env);
lowerLambda returns its func_ref. Rejected (no silent miscompile): a capturing
closure into a bare slot (env has nowhere to live) and a failable closure into
a non-failable slot (the ERR E5.1 FFI-boundary rule).
- Arrow-body failable closures (-> (T,!) => expr) now wrap the bare success value
into {value, 0} via lowerFailableSuccessReturn (the implicit return previously
returned a malformed tuple → caught value read as 0).
The isLambda .bang parser fix (failable closure literals parse) already landed in
485b4fa. Regressions: examples/0309-closures-literal-as-bare-fn-param (non-
failable, block + arrow, called in callee) + 1039-errors-failable-closure-literal
(failable, block + arrow, direct + Closure(...) param). Resolves issue 0060
(remaining E5.1 follow-ups noted in the .md). Suite: 328 passed.
Probing ERR/E5.1 (composition with closures) surfaced pre-existing closure-
literal lowering bugs: a closure literal passed as a function-type argument and
called inside the callee returns wrong values (block-body 192, arrow-body 20,
want 10 — non-failable too; the working contrast passes the value as a separate
arg, examples/0302). On top of that, failable closure returns don't parse
(isLambda omits .bang — one-line fix in the issue) and arrow-body failable
closures miscompile (return 0); block-body failable closures called directly
work. Runnable repro + parser patch + investigation prompt in the issue.
E5.1 paused per the impassable rule rather than built on miscompiling closures;
the parser fix + a regression example were reverted to avoid landing silently-
miscompiling failable closures on master.
