Passing in an array of complex structs

Question

I am wondering what pattern I am supposed to follow in Solidity to take in an array of structs as a parameter. I am translating code from CPP and mostly everything translates directly besides this (and variable scoping in functions).

TypeError: This type is only supported in the new experimental ABI encoder. Use "pragma experimental ABIEncoderV2;" to enable the feature.

    struct HorseRaceData {
            HorseData data;
            uint64 currentSpeed;
            uint64 currentStamina;
            uint64 distanceTraveled;
            uint64 time;
            bool done;
    }

    function placementSimulation (HorseRaceData[] memory horses) public {...}

Answer 1

As a general rule, try to reduce large operations to a more granular style and rely on clients to iterate as needed. There are exceptions, but you could do worse than addressing concerns like lists one row at a time.

The elements of the list are structs which are also beyond the capabilities of the current ABI encoder. What you can do is pass in members. Something like:

    pragma solidity 0.5.1;
    
    contract Horses {
        
        struct HorseStruct {
            uint64 currentSpeed;
            uint64 currentStamina;
            uint64 distanceTraveled;
            uint64 time;
            bool done;
        }
        
        HorseStruct[] public horseStructs;
        
        function placementSimulation (uint64 currentSpeed, uint64 currentStamina, uint64 distanceTraveled,  uint64 time, bool done) public {
            HorseStruct memory horseData = HorseStruct({
                currentSpeed: currentSpeed,
                currentStamina: currentStamina,
                distanceTraveled: distanceTraveled,
                time: time,
                done: done});
            horseStructs.push(horseData);
        }
            
    }

Have a look over here for some general patterns: Are there well-solved and simple storage patterns for Solidity?

Hope it helps.