Module model

[perama-v]

I am thinking there might be two ways to extend a contract, e.g., an ERC token to be Ownable.

1. A myToken.cairo with top-of-file import-style mechanism: from ozcc import ERC, Ownable.
2. A generator CLI program: ozcc generate ERC Ownable that produces a populated myToken.cairo.

Option 1 would mimic existing Solidity experience, and would involve functions overriding others in a hierarchy.

Option 2 would involve the program fetching only non-overridden functions from the chosen combination and placing those in a file.

Both options are compatible with pre-generated common patterns (721, 721-ownable, 721-ownable-enumerable, 721-enumerable). Option 2 might result in a less-complex contract file, because there would be no override patterns for the developer to mentally manage.

[perama-v]

One mechanism for option 2 could be:

Each function has a specially formatted comment above the function:

ERC20.cairo:

##--## overwritten_by: Ownable/xyz
@external
func xyz():
    # abcd
    return ()
end

Ownable.cairo:

@external
func xyz():
    # cdef
    return ()
end

When the contract is pieced together from two different files, this comment could be used to select only one of them.

[perama-v]

The resulting myToken.cairo would then contain:

all_builtins_here

all_imports_here

all_storage_here

### Custom MyToken logic ###
@external
func mintMyToken{
        pre_populated_pointers_here
    }(
        number_to_mint : felt
    ):
    only_owner()
    _mint(number_to_mint)
    return ()
end

# Custom function 2 here

### End of custom section ###

### Standardised token logic ###
@external
func xyz():
    # cdef
    return ()
end

remaining_standardised_functions_here

(The xyz function containing #abcd does not appear in the file)