Create a smart contract in which user can deposit ether and get ERC-20 tokens
It's unidirectional and ERC-20 tokens can not be used to buy other ERC-20 tokens
Ether -> ERC-20 only
Store orders on chain. This is not common anymore because if the orderbook is visible other people can frontrun you.
This is more for learning.
There will (buy, sell) orders
- Limit order
- Market order