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generic-collectionseiffel

How to specify when giving a generic parameter that it should implement some specific creation method?

How to specify when giving a generic parameter that it should implement some specific creation method? as LIST[G -> create make end] doesn't work :-(

class diagram

In my particular case, * SMA_INVERTER_MANAGER_CSV has inherited from CONSUMPTION_SECTOR_MODBUS_DEVICE_CSVa list of devices as devices: LINKED_SET[G] as G -> MEASURING_POINT_MODBUS_DEVICE create make_from_file_path end.

I'd like the SMA_INVERTER_MANAGER_CSV class to be able into devices: LINKED_SET[G] to be able to have either JANITZA_DEVICE, SUNSPEC_DEVICE, ABB_DEVICE, etc. Giving the generic parameter as MEASURING_POINT_MODBUS_DEVICE seems to come out of a sense, but how do I specify that I'd like the creation method to be make_from_file_path

Hope the description is sufficient to understand, refactoring I think this question is linked -> explicit creation type not conforming to type of target

The only workaround for the moment I found working for the moment is

class
    SMA_INVERTER_MANAGER_CSV

inherit
    CONSUMPTION_SECTOR_MODBUS_DEVICE_CSV[SUNSPEC_DEVICE]

create
    make


end

but I'd like it to be

class
    SMA_INVERTER_MANAGER_CSV

inherit
    CONSUMPTION_SECTOR_MODBUS_DEVICE_CSV[MEASURING_POINT_MODBUS_DEVICE]

create
    make


end

which would generate a conformance problem because MEASURING_POINT_MODBUS_DEVICE generic parameter doesn't specify make_from_file_path as creation procedure as its deferred

Solution

  • There is more than a conformance problem. MEASURING_POINT_MODBUS_DEVICE is deferred. Therefore, it cannot be used as an actual parameter for CONSUMPTION_SECTOR_MODBUS_DEVICE_CSV. If it were allowed, how would CONSUMPTION_SECTOR_MODBUS_DEVICE_CSV create an instance of a deferred class?

    One possible solution — supplying an effective class — is mentioned in the question. Another solution is to add a formal generic parameter to SMA_INVERTER_MANAGER_CSV with the corresponding constraint and to use it for the actual generic of CONSUMPTION_SECTOR_MODBUS_DEVICE_CSV.