Add ScriptContext test

[ana-pantilie]

Fixes https://github.com/IntersectMBO/plutus-private/issues/1479

The AsData version is actually slightly better (in script size) than the manually optimised version! I am not entirely sure why, since I tried multiple versions of the manually optimised one, and this was the best one.

[zliu41]

Add some comments - it's hard to tell from the name - forwardWithStakeTrick - what it does.

[zliu41]

Don't include the script context in the golden files - it serves no purpose.

[zliu41]

I don't think you need member' here - you can use PlutusTx.Data.List.elem (or something very similar).

Even if you do need to expose member', it should be exposed from the List module (since it has nothing to do with Map), and it should have Haddock.

[ana-pantilie]

The rest here is a map, not a list. Converting it to a list would be costly. I have, however, used member instead of member', and removed the member' and the insert' functions from the export list. I was not sure if the compiler could figure out that Map k a is representationally equivalent to BuiltinList (BuiltinPair ...), but it can so there is no overhead.

[zliu41]

This is still awkward. Do we need to convert Map into a BuiltinList? Can we convert it into a PlutusTx.Data.List, without losing efficiency? If BuiltinList is indeed more efficient, then it suggests that the Plinth library should have some utilities for working with BuiltinList - such as elem, find, lookup and so on.

[ana-pantilie]

Can we convert it into a PlutusTx.Data.List, without losing efficiency?

No. Map is BuiltinList (BuiltinPair BuiltinData BuiltinData) and List is BuiltinList BuiltinData. We would need to traverse the BuiltinList and transform each BuiltinPair into a BuiltinData.

If BuiltinList is indeed more efficient, then it suggests that the Plinth library should have some utilities for working with BuiltinList - such as elem, find, lookup and so on.

Would we use BuiltinList in the ScriptContext directly?

@zliu41

[zliu41]

No, but once you convert Map to BuiltinList, having to convert it back to a Map in order to call member or whatever, is awkward. Not to mention after some operations on the BuiltinList, it may no longer be a Map (and indeed, converting it back requires an unsafe operation).

It would be much nicer if there's a lookup operation and similar operations on BuiltinList, so once you have the list you just work with the list.

[zliu41]

Could you open an issue for adding BuiltinList operations.

[ana-pantilie]

I think you're right. Opened an issue: #6977