# Session save — 2026-09-19 (m2compiler-V3)

## Where we are

HEAD: `1505ca8` — `v3-step1.11`, suite **35/35** (15 run + 20 reject).
Repo: `/home/eric/Projets/Projets-Modula2/MyWork/m2compiler-V3`, no remote
(push recipe in untracked `git.txt` → `http://git.yojik.eu/eric/M2compiler-V3.git`).
Uncommitted right now: `docs/grammar.md` (fresh extraction, needs a
commit decision). `git.txt` intentionally untracked.

## Tag lineage (all green at every tag)

v3-step1 (5/5 integer pipeline) → 1.1 (scope-tree+BST symtab) → 1.2
(heap-allocated storage) → 1.3 (0x-only hex, a-f, E-exponents, `//`)
→ 1.4 (3 units, imports, opaque, nesting) → 1.5 (`file:line:col`
console errors) → 1.6 (showcase1=50) → 1.7 (scalar TYPEs, headings,
bodies, FORWARD) → 1.8 (showcase2=71) → 1.9 (statements+booleans,
QBE block discipline) → 1.10 (Clarion classes + corrected OOP.txt
sketch) → 1.11 (showcase4=44, showcase5=7×230 class frontier);
v3-step2 (REAL lowering, scalar story complete); docs-only commits
(OOP.txt ref, root README) untagged between 1.9 and 2.

## Grammar status (`compiler/src/M2.atg`, ~900 lines, LL(1) with one
benign Coco warning in TypeBlock — verified correct codegen)

Lowers: program modules; CONST/VAR/scalar TYPEs (named, subrange
w/ folded literal bounds, enum declared); full scalar arith incl.
REAL (`d`, swtof, cXXd); relations; eager AND/OR/NOT; IF/CASE
(labels+ranges+ELSE, compare-chain)/WHILE/REPEAT/LOOP+EXIT/FOR-full-BY/
RETURN(232-checked). Parse-now+230: DEFINITION/IMPLEMENTATION,
nesting (+EXPORT), proc bodies, FORWARD, enum use, classes
(decl+single-inheritance+IMPLEMENTATION blocks+VIRTUAL).
Still syntax errors: ARRAY/RECORD/SET/POINTER, WITH, IN, calls.

## Locked decisions (do not relitigate without cause)

Classic idents (no `_`, R10 reserves leading `_`); `0x`-only hex;
`#` only; `NOT/AND/OR` only; no `B/C`; unary minus at expr start
only (Wirth); `;` method separators (example over sketch);
single inheritance; every ARRAY = LONGCARD count + elements
(inline, element counts, no NUL); UCHAR=32-bit + UString=count+
codepoints, UTF-8 edges, hard lex errors; self-host bar =
byte-identical `.ssa` over 3 stages. Truncating DIV/MOD (`/` on
ints too, Test2 parity). Eager booleans. Test2-compat QbeGen
signatures kept for growth.

## Open threads / next = step 3 composites

ARRAY/RECORD/SET/POINTER + length-prefixed layout + WITH + IN;
`docs/plan.md` + `docs/summary_step3.md` (stub) hold the scope.
Also pending: unmatched-FORWARD 231, fwd/body signature compare,
CHAR-arith policy, enum lowering, LONGINT quads, sibling-method
visibility (step 4 calls), class lowering (vtable/THIS), `0b` +
digit separators, `grammar.md` regen hook in build.sh (offered,
not done). A phantom `t_class` mid-session failure never
reproduced — see `docs/summary_step1.10.md` §3; clean-rebuild
first if anything similar appears.

## Resume commands

```sh
cd /home/eric/Projets/Projets-Modula2/MyWork/m2compiler-V3/compiler
./build.sh && ./run_tests.sh   # expect 35/35
```
Then: interactive § statements for composites (ask which first:
ARRAY+indexing, RECORD+WITH, SET+IN, POINTER).