Feedback from @wilsoncusack and @vasa-develop

[Anish-Agnihotri]

Copying great feedback received via Twitter DMS:

Wilson

• [x] Gas can be saved during struct initialization, since these values all are already initialized to 0.
• [ ] Interest rate does not support decimals, recommended to use a scalar constant.
• [x] No need for == true here.
• [x] No need for a loan capacity check because the draw capacity check will already fail (since 0<0 == false).
• [x] More idiomatic to start loans at 1 (uint256 loanId = ++numLoans;).

Vasa

• [ ] The current code uses a max-sized struct, which prevents me from adding a isRepaid boolean without stack-overflowing. This is currently solved by using the tokenOwner struct param as a dirty field to represent a paid loan if it is equal to 0x0. Vasa recommended using address and uint arrays to reduce stack size:

struct PawnLoan {
  address[3] addrs; // [tokenAddress, tokenOwner, lender]
  uint256[9] uints; // [tokenId, interestRate, loanAmount, maxLoanAmount, loanAmountDrawn, firstBidTime, lastBidTime, historicInterest, loanCompleteTime]
  bool isRepaid;
}

Alternatively, I could also use a mapping to represent repaid loans which may offer cheaper lookup.