# V3 step 3.5 — showcase8: the everything-tour (done 2026-09-20)

Suite 57/57 (26 run — incl. 3 trap-aborts — + 31 reject).
Single-file proof that every lowered construct composes:
`showcase8.mod` → ExitCode 170, hand-computed, first try.

## Coverage (in execution order)

- `FOR`-filled vector + indexed accumulation (arrays)
- Nested matrix stores (multi-dim headers)
- Set union + `IN` gate
- String store + indexed `CHAR` compare
- `RECORD` + nested `WITH` field updates
- Subrange + alias use (zero net, for coverage)
- `INTEGER`→`REAL` conversion, real arithmetic + comparison
- `CASE` with ranges + `ELSE`
- `WHILE` down-loop, `REPEAT` up-loop, `LOOP`/`EXIT` up-loop
- Final boolean + char gate into `ExitCode`

## Arithmetic (hand check)

100 (vector) + 6 (matrix) + 1 (IN) + 2 (char) + 42 (WITH fields)
+ 7 (subrange) + 10 (real gate) + 1 (CASE) − 4 (WHILE) + 2
(REPEAT) + 3 (LOOP) = 170. Every intermediate asserted in the
file comments; the binary agreed on the first run.

## Notes

- 170 < 256 by design (exit codes are 8-bit); the tour stays
  clear of that ceiling deliberately.
- `WITH`-on-field-designator and deep-copy paths from 3.4 both
  execute here (not just in their unit tests).
- Next showcase point: 3.6 pointers (linked structures need
  `NEW`; currently impossible to build one).