Uniswap Hooks

one question for a point of clarity on uni pools

token 0 <> token 1 

these tokens are lexicographically sorted by their addresses. 

what is the reasoning behind sorting tokens in a pool like that? particularly in terms of the sc design choice there

devrel / solutions engineer & independent researcher

simplify and say a pools are identified only by token pair to maintain state, you'll need to have two mappings

1. Token 0 => (Token 1 => PoolState)
2. Token 1 => (Token 0 => PoolState)

to avoid this, a deterministic sorting algo is used to keep the state mapping uni-directional

this is also not new btw and has been done for many versions of uniswap

See screenshot from Uniswap v2 codebase:

haardik.dev | Founder @learnweb3 | lead instructor /uniswaphooks | building @openfarcaster

in v4 because pools have more parameters they're identified by (fee, hook address, etc) - we use the hash of an abi.encoded PoolKey to represent a pool

if tokens were not sorted, there would be two hashes for the same pool with same tokens except 0 and 1 flipped around

same issue