I have written an ABI sorter, as per the above suggestion.
The code dives in and sorts internal inputs
and outputs
and then comes out to sort the higher level surface of the ABI. The multi-level sort order is by type
then by name
.
Here is an example using the Standard ERC20 ABI Text
Example ERC20 input - unsorted
[{"constant": true, "inputs": [], "name": "name", "outputs": [{"name": "", "type": "string"}], "payable": false, "stateMutability": "view", "type": "function"}, {"constant": false, "inputs": [{"name": "_spender", "type": "address"}, {"name": "_value", "type": "uint256"}], "name": "approve", "outputs": [{"name": "", "type": "bool"}], "payable": false, "stateMutability": "nonpayable", "type": "function"}, {"constant": true, "inputs": [], "name": "totalSupply", "outputs": [{"name": "", "type": "uint256"}], "payable": false, "stateMutability": "view", "type": "function"}, {"constant": false, "inputs": [{"name": "_from", "type": "address"}, {"name": "_to", "type": "address"}, {"name": "_value", "type": "uint256"}], "name": "transferFrom", "outputs": [{"name": "", "type": "bool"}], "payable": false, "stateMutability": "nonpayable", "type": "function"}, {"constant": true, "inputs": [], "name": "decimals", "outputs": [{"name": "", "type": "uint8"}], "payable": false, "stateMutability": "view", "type": "function"}, {"constant": true, "inputs": [{"name": "_owner", "type": "address"}], "name": "balanceOf", "outputs": [{"name": "balance", "type": "uint256"}], "payable": false, "stateMutability": "view", "type": "function"}, {"constant": true, "inputs": [], "name": "symbol", "outputs": [{"name": "", "type": "string"}], "payable": false, "stateMutability": "view", "type": "function"}, {"constant": false, "inputs": [{"name": "_to", "type": "address"}, {"name": "_value", "type": "uint256"}], "name": "transfer", "outputs": [{"name": "", "type": "bool"}], "payable": false, "stateMutability": "nonpayable", "type": "function"}, {"constant": true, "inputs": [{"name": "_owner", "type": "address"}, {"name": "_spender", "type": "address"}], "name": "allowance", "outputs": [{"name": "", "type": "uint256"}], "payable": false, "stateMutability": "view", "type": "function"}, {"payable": true, "stateMutability": "payable", "type": "fallback"}, {"anonymous": false, "inputs": [{"indexed": true, "name": "owner", "type": "address"}, {"indexed": true, "name": "spender", "type": "address"}, {"indexed": false, "name": "value", "type": "uint256"}], "name": "Approval", "type": "event"}, {"anonymous": false, "inputs": [{"indexed": true, "name": "from", "type": "address"}, {"indexed": true, "name": "to", "type": "address"}, {"indexed": false, "name": "value", "type": "uint256"}], "name": "Transfer", "type": "event"}]
Example ERC20 output - sorted
[{"anonymous":false,"inputs":[{"indexed":true,"name":"owner","type":"address"},{"indexed":true,"name":"spender","type":"address"},{"indexed":false,"name":"value","type":"uint256"}],"name":"Approval","type":"event"},{"anonymous":false,"inputs":[{"indexed":true,"name":"from","type":"address"},{"indexed":true,"name":"to","type":"address"},{"indexed":false,"name":"value","type":"uint256"}],"name":"Transfer","type":"event"},{"payable":true,"stateMutability":"payable","type":"fallback"},{"constant":true,"inputs":[{"name":"_owner","type":"address"},{"name":"_spender","type":"address"}],"name":"allowance","outputs":[{"name":"","type":"uint256"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":false,"inputs":[{"name":"_spender","type":"address"},{"name":"_value","type":"uint256"}],"name":"approve","outputs":[{"name":"","type":"bool"}],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":true,"inputs":[{"name":"_owner","type":"address"}],"name":"balanceOf","outputs":[{"name":"balance","type":"uint256"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":true,"inputs":[],"name":"decimals","outputs":[{"name":"","type":"uint8"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":true,"inputs":[],"name":"name","outputs":[{"name":"","type":"string"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":true,"inputs":[],"name":"symbol","outputs":[{"name":"","type":"string"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":true,"inputs":[],"name":"totalSupply","outputs":[{"name":"","type":"uint256"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":false,"inputs":[{"name":"_to","type":"address"},{"name":"_value","type":"uint256"}],"name":"transfer","outputs":[{"name":"","type":"bool"}],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":false,"inputs":[{"name":"_from","type":"address"},{"name":"_to","type":"address"},{"name":"_value","type":"uint256"}],"name":"transferFrom","outputs":[{"name":"","type":"bool"}],"payable":false,"stateMutability":"nonpayable","type":"function"}]
Here is a link to the code which performs the sort.
I ended up writing this without help from Libraries (aside from import json
). Partly because we can now transpose the logic of my code to C++ and partly because (as it turns out) Python’s lambda
and Python’s itemgetter
did not entertain the absence of the name
key in the fallback function anyway.