# Michelson elaborator cleanups

## Revive onchain contracts collection

Prerequisite to next point
- https://gitlab.com/nomadic-labs/tezos/-/commits/vbot@get_contracts/
- https://gitlab.com/nomadic-labs/smart-contracts/-/merge_requests/3

### State of stored lambdas
Stored lambdas: https://gitlab.com/metastatedev/tezos/-/issues/153#note_455995114

Lambdas in big maps: none

`UNPACK`ed lambdas:
- [`exprtanLAEXhEwgMWYT3pp1C94f1izZQiZwWd8JERNr6EtMFD2hxne.tz`](https://gitlab.com/nomadic-labs/smart-contracts/-/blob/master/onchain/mainnet/scripts/exprtanLAEXhEwgMWYT3pp1C94f1izZQiZwWd8JERNr6EtMFD2hxne.tz)
- in stored lambdas

Packed lambdas in big maps: see below.

### How to get all the code?

- Code is:
- smart contracts' `code`
- lambdas
- Lambdas are:
- clear lambdas in contracts' storage or bigmaps
- bytes unpacked as a type containing lambdas
- Bytes are:
- constants in code
- clear bytes in contracts' storage or bigmaps
- bytes unpacked as a type containing bytes

So:
- collect all bytes:
1. start with contracts' constants, storages, and bigmaps
2. try to unpack them
- on success, collect bytes in them
- and do 2 recursively (it finishes as nested bytes are smaller than their container)
- collect all UNPACK types containing lambdas (can be done in Micheline)
- from contracts' code
- from all stored values, and unpacked values from 2 above
- collect lambdas trying to parse unpacked values with types collected above
- keep only the lambda part of the unpacked value

Done: https://gitlab.com/nomadic-labs/smart-contracts/-/merge_requests/4

## Remove legacy feature

For each `if/when legacy`:
  if was introduced after the protocol currently running
    add a comment to specify when it was introduced
  else
    if no existing contract uses it
      remove it
    else
      add a rewriting to the stitching

See https://gitlab.com/nomadic-labs/tezos/-/issues/93

1. Packable contracts
- In `check_packable`
- Used in `PACK` only
2. `FAILWITH` on non-packable (added in Edo)
3. check for `well_formed_entrypoints`
- In `CREATE_CONTRACT`
- In `parse_code`
- In `typecheck_code`
4. `parse_toplevel` ignores spurious annotations
5. Will go away with annotations:
- In `merge_type_annot/merge_field_annot`
- In `parse_ty` for `T_option`
- In `parse_storage_ty`
- In `parse_(data)`

## Remove annotations

https://gitlab.com/metastatedev/tezos/-/issues/113

## Fix injectivity of types in the ty GADT

To remove `assert false` branches and help next point.

https://gitlab.com/metastatedev/tezos/-/issues/112

Ask Benjamin, he may have a patch for that already.

## Encode type properties in GADT

Typechecking has become too complex to rely only on humain brain.

Start with `comparable`.

Make sure it doesn't make everything bigger/slower (sync with Yann, hash-consing will help here).

Also consider local witnesses, like `has_big_map`.

## Random

Cons_none: type not needed in interpreter