# Session summary — 2026-10-01: result suffixes, coroutines, core library

Suite **173/173**; self-hosting fixpoint **OK** (image
**2,785,569 bytes**).  Work on items 2 (result suffixes), 4
(coroutines) and 6 (library holes) of the remaining-gaps list; items
1 (`GOTO`), 3 (generics) and 5 (multiple inheritance) were left alone.

## 1. Result suffixes (`F()^`, `F()[i]`, `F().field`)

New `ResultComp` production (M2.atg) applied to a call result inside
`Fact`: the `[ ArgList { ResultComp } ]` group is entered only when the
lookahead is `(`, so the component starters `[ . ^` stay disjoint from
`Design`'s own component loop (no new Coco/R LL(1) conflict).  After a
call the result is in `t`/`q` with `sfx := FALSE`; `^` dereferences a
pointer result, `[i]` indexes an array result, `.f` selects a record
field, and a final scalar is loaded with `ElemLoad`.  Expression context
only; statement-context suffix targets and chained post-call calls are
not accepted.

## 2. PIM coroutines (`SYSTEM.NEWPROCESS`/`TRANSFER`/`IOTRANSFER`)

- `PROCESS` is predefined pointer-sized; `PROC` is a new parameterless
  procedure-type descriptor (`dProc`).
- `NEWPROCESS`, `TRANSFER`, `IOTRANSFER` are predefined external
  procedures (`SymTab.PredefCProc`/`AddFormal`) with explicit
  signatures; calls bind to `m2_newprocess`/`m2_transfer`/
  `m2_iotransfer`.
- The shim implements them over `ucontext`: `NEWPROCESS` builds a
  context on the caller's workspace, `TRANSFER` saves/resumes.
  `IOTRANSFER` degrades to a transfer (no interrupt subsystem).

## 3. Backend fixes exposed by the library

- `ElemLoad`/`ElemStore` and the function-parameter prologue treated
  procedure values (and LONGINT) as 32-bit; they are now `loadl`/
  `storel` (`ClProc`, `ClClass`, `ClLong`).  This fixes arrays of
  procedure values (`StdIO`'s push/pop stacks) and proc/long formals.
- The M2 driver's session file table was capped at 32 sources; raised
  to 128 (`compiler.frm`).
- `Math.ln`/`Math.arctan` now wrap the C `log`/`atan` (they bound to
  non-existent `ln`/`arctan`).

## 4. Standard library (gm2/ISO names, layered on the shim)

Added: `ConvTypes`, `IOConsts`, `SIOResult`, `TERMINATION`, `StrIO`,
`InOut`, `StdIO`, `WholeStr`, `RealStr`, `LongStr`, `LongMath`,
`STextIO`, `SWholeIO`, `SRealIO`, `LongIO`, `DynamicStrings` (core
subset), `SysStorage`.  `TERMINATION.def` is uppercase (gm2 spelling).

New shim helpers: `m2readline`, `m2writeintwidth`, `m2realconv`,
`m2terminating`, `m2hashalted`, and the `m2ds*` DynamicStrings core
(heap C strings; `String` is an opaque type completed to `ADDRESS`).

Still missing from the §2 list: `LongWholeIO`, `wrapclock`/`wraptime`/
`wrapc`, `TimeString`, and the gm2 device framework (`ChanConsts`/
`GenDevIF`/`DeviceTablePtr`/`StdChans`/`StreamFile`/`FIO`).

## Tests (173, was 171)

New: `t_resultsfx` (deref/index/field of call results), `t_coroutine`
(two coroutines ping-pong), `t_dynstr` (DynamicStrings + SysStorage),
`library1` (a session exercising 16 library modules).

## Resume

```sh
cd .../m2compiler-V3
./bootstrap/fixpoint.sh                       # FIXPOINT OK
cd compiler && ./build.sh && ./run_tests.sh   # 173/173
```

## Remaining

`GOTO`/labels, generics, multiple inheritance (deliberate), full
forward variables, statement-context result suffixes, and the channel/
device library holes listed above.