Struct containing array containing array initialization problem

Question

I am trying write a contract like below.

pragma solidity ^0.4.9;

/* Contract accepting ethers during 10 minutes */
contract Trading {

    address receivingAccount;
    uint deadline;

    struct Asset {
        string name;
        uint price;
        uint barcode;
    }

    struct Stock {
        Asset asset;
        uint count;
    }

    struct Vendor {
        string name;
        address account;
        Stock[] stocks;
    }

    Asset[] assets;
    Vendor[] vendors;

    /*  at initialization, setup the owner */
    function Trading(address _vendor0, address _vendor1) {
        // create 2 assets
        assets.push(Asset("Asset0", 12, 1234));
        Asset memory asset1 = Asset("Asset1", 34, 5678);
        assets.push(asset1);

        // create 2 vendors
        Vendor memory vendor0 = Vendor("Vendor0", _vendor0, new Stock[](5));
        Vendor memory vendor1 = Vendor("Vendor1", _vendor1, new Stock[](5));

        // add assets to the stock of vendor0
        vendor0.stocks[0] = Stock(assets[0], 2);
        vendor0.stocks[1] = Stock(assets[1], 2);
        vendors.push(vendor0);

        // add assets to the stock of vendor1
        vendor1.stocks[0] = Stock(assets[0], 1);
        vendor1.stocks[1] = Stock(assets[1], 1);

        // set the deadline as 10 minutes
        deadline = now + 10 * 1 minutes;
    }  

    function listAssetBarcodes() constant returns (uint[]) {
        uint[] memory barcodes = new uint[](assets.length);
        for (uint i=0; i<assets.length; i++) {
            barcodes[i] = assets[i].barcode;
        }
        return barcodes;
    }

    modifier afterDeadline() { if (now >= deadline) _; }

    /* checks if the time limit has been reached and ends the contract */
    function dispose() afterDeadline {
        suicide(receivingAccount);
    }
}

However, when I add the statement vendors.push(vendor0); to the constructor (as above) I am having the following compilation error from the online compiler:

Unimplemented feature (/src/libsolidity/codegen/ArrayUtils.cpp:215): Copying of type struct Trading.Stock memory[] memory to storage not yet supported.

Can anyone help me how can I use the arrays in Solidity properly? Or is there a list or vector like structure we can use or we are obligated to use arrays for the moment?

Answer 1

Based on error message somewhen this feature will be implemented. For now you can do something like this:

    // create 2 vendors
    // Vendor memory vendor0 = Vendor("Vendor0", _vendor0, new Stock[](5));
    // Vendor memory vendor1 = Vendor("Vendor1", _vendor1, new Stock[](5));

    // // add assets to the stock of vendor0
    // vendor0.stocks[0] = Stock(assets[0], 2);
    // vendor0.stocks[1] = Stock(assets[1], 2);
    // vendors.push(vendor0);

    // // add assets to the stock of vendor1
    // vendor1.stocks[0] = Stock(assets[0], 1);
    // vendor1.stocks[1] = Stock(assets[1], 1);

    // add assets to the stock of vendor0
    vendors.push(Vendor("Vendor0", _vendor0, new Stock[](5)));
    vendors[vendors.length-1].stocks[0] = Stock(assets[0], 2);
    vendors[vendors.length-1].stocks[1] = Stock(assets[1], 2);


    // add assets to the stock of vendor1
    vendors.push(Vendor("Vendor1", _vendor1, new Stock[](5)));
    vendors[vendors.length-1].stocks[0] = Stock(assets[0], 1);
    vendors[vendors.length-1].stocks[1] = Stock(assets[1], 1);

Answer 2

You can use mapping(uint => Stock) instead of Stock[].

So you can implement Vendor struct as follows:

struct Vendor {
    string name;
    address account;
    mapping(uint => Stock) stocks;
    uint stockCount;    
}