# V3 step 1.7 — declarations: scalar TYPEs, headings, bodies, FORWARD (done 2026-09-19)

Interactive grammar §3, landed syntax-now/backend-later like §2.
Suite 15/15 (5 run + 10 reject), LL(1)-clean.

## Grammar (`compiler/src/M2.atg`)

- `TypeBlock<isDef>` replaces `OpaqueBlock` in both DefUnit (TRUE)
  and DeclSeq (FALSE). `TypeItem = ident ("=" Type | /*opaque*/)` —
  the branch happens *after* the ident so `=` vs `;` keeps it LL(1).
  Opaque outside DEFINITION → new 231 (frame text added).
- Scalar-phase `Type = TypeIdent | Subrange | Enum`. Composites
  (ARRAY/RECORD/SET/POINTER) are still syntax errors → step 3.
- `TypeIdent` factored (named/predef/import-tolerant) and reused by
  VarDecl (which now also accepts imported type names as Invalid).
- `Subrange = "[" Expr ".." Expr "]"`: integer-family bounds folded
  via new `SymTab.ConstInt` (literals incl. `0x`, folded unary minus);
  non-literal/non-int/inverted bounds → 230. Stored via new
  `NewSubR(lo,hi)`; baseless `FSub` resolves to `ClInt` (ClassOf fix).
- `Enum = "(" idents ")"`: literals entered as KindConst of the new
  type. *Use* of non-INTEGER consts (enum/char/bool/real) is now 230
  (Design KindConst branch tightened; NIL stays silent).
- `ProcHeading<pn>` (OUT name): `EnterProc`/`ReenterProc` + optional
  formals + optional `: TypeIdent` result. DefUnit uses it + `PopScope`.
- `FormalParams`: `"(" [groups] ")"`, `VAR` per group, `EnterParam`
  + `FixPending` (params behave as typed variables in bodies).
- `ProcDecl = heading ";" ("FORWARD" | Block)`; Block parses decls +
  optional body with END-name check, one 230 (lowering = step 4).
  Wirth trailing-`;` convention (V1 parity): DeclSeq uses
  `ProcDecl ";"`.

## SymTab growth (additive, no interface breakage)

KindProc/KindParam; node fields rslt/plink/isVar/fwd; EnterProc
(pushes scope), ReenterProc (fwd→body, fresh signature), EnterParam
(pend-records + positional chain), SetProcRes/ProcRes/MarkFwd,
NewSubR + tlo/thi, ConstInt. PrintTable shows PROC/PARAM.

## Bugs found by the new tests (all fixed, suite proved each)

1. `ProcDecl ";"` missing → FORWARD's trailing `;` misparsed as
   'END' expected (V1 had the same separator rule).
2. `[0..9]` lexed wrong without Test2's `CONTEXT("..")` guard on the
   integer token (spaced `[0 .. 9]` worked, unspaced didn't).
3. `ReenterProc` didn't reset `plink` → second param list chained
   onto a NIL tail: SIGABRT heap crash, bisected to fwd+params on
   both headings.
4. `EnterParam` didn't pend-record → params stayed InvalidType and
   every use falsely 230'd (5 errors in t_proc instead of 1).

## Tests

`t_types` run → 8 (subrange/alias/hex use); `t_enumdecl`,
`t_proc` (value + VAR formals, result), `t_forward` (fwd/body pair)
→ single 230s; `t_bad_opaque` → 231. Deferred on record: unmatched
FORWARD (no body) is silently accepted — step 4 makes it 231;
fwd/body signature compare also step 4.