{
    "Function": "_matcho",
    "File": "contracts/RubiconMarket.sol",
    "Parent Contracts": [
        "contracts/RubiconMarket.sol",
        "contracts/RubiconMarket.sol",
        "contracts/RubiconMarket.sol",
        "contracts/RubiconMarket.sol",
        "contracts/RubiconMarket.sol",
        "contracts/RubiconMarket.sol",
        "contracts/RubiconMarket.sol",
        "contracts/RubiconMarket.sol"
    ],
    "High-Level Calls": [],
    "Internal Calls": [
        "offer",
        "mul",
        "mul",
        "mul",
        "min",
        "mul",
        "_sort",
        "mul",
        "buy",
        "min",
        "min",
        "sub"
    ],
    "Library Calls": [],
    "Low-Level Calls": [],
    "Code": "function _matcho(\n        uint256 t_pay_amt, //taker sell how much\n        ERC20 t_pay_gem, //taker sell which token\n        uint256 t_buy_amt, //taker buy how much\n        ERC20 t_buy_gem, //taker buy which token\n        uint256 pos, //position id\n        bool rounding //match \"close enough\" orders?\n    ) internal returns (uint256 id) {\n        uint256 best_maker_id; //highest maker id\n        uint256 t_buy_amt_old; //taker buy how much saved\n        uint256 m_buy_amt; //maker offer wants to buy this much token\n        uint256 m_pay_amt; //maker offer wants to sell this much token\n\n        // there is at least one offer stored for token pair\n        while (_best[address(t_buy_gem)][address(t_pay_gem)] > 0) {\n            best_maker_id = _best[address(t_buy_gem)][address(t_pay_gem)];\n            m_buy_amt = offers[best_maker_id].buy_amt;\n            m_pay_amt = offers[best_maker_id].pay_amt;\n\n            // Ugly hack to work around rounding errors. Based on the idea that\n            // the furthest the amounts can stray from their \"true\" values is 1.\n            // Ergo the worst case has t_pay_amt and m_pay_amt at +1 away from\n            // their \"correct\" values and m_buy_amt and t_buy_amt at -1.\n            // Since (c - 1) * (d - 1) > (a + 1) * (b + 1) is equivalent to\n            // c * d > a * b + a + b + c + d, we write...\n            if (\n                mul(m_buy_amt, t_buy_amt) >\n                mul(t_pay_amt, m_pay_amt) +\n                    (\n                        rounding\n                            ? m_buy_amt + t_buy_amt + t_pay_amt + m_pay_amt\n                            : 0\n                    )\n            ) {\n                break;\n            }\n            // ^ The `rounding` parameter is a compromise borne of a couple days\n            // of discussion.\n            buy(best_maker_id, min(m_pay_amt, t_buy_amt));\n            emit LogMatch(id, min(m_pay_amt, t_buy_amt));\n            t_buy_amt_old = t_buy_amt;\n            t_buy_amt = sub(t_buy_amt, min(m_pay_amt, t_buy_amt));\n            t_pay_amt = mul(t_buy_amt, t_pay_amt) / t_buy_amt_old;\n\n            if (t_pay_amt == 0 || t_buy_amt == 0) {\n                break;\n            }\n        }\n\n        if (\n            t_buy_amt > 0 &&\n            t_pay_amt > 0 &&\n            t_pay_amt >= _dust[address(t_pay_gem)]\n        ) {\n            //new offer should be created\n            id = super.offer(t_pay_amt, t_pay_gem, t_buy_amt, t_buy_gem);\n            //insert offer into the sorted list\n            _sort(id, pos);\n        }\n    }"
}