tl;dr
- EELS is an execution layer reference implementation in Python.
- It is updated with mainnet.
- It fills exams, and passes current ones.
- There’s an instance of an EIP carried out in EELS under.
Introduction
After greater than a 12 months in growth, we’re happy to publicly introduce the Ethereum Execution Layer Specification (affectionately often known as EELS.) EELS is a Python reference implementation of the core elements of an Ethereum execution consumer targeted on readability and readability. Supposed as a religious successor to the Yellow Paper that is extra programmer pleasant and up-to-date with post-merge forks, EELS can fill and execute state exams, observe mainnet1, and is a good place to prototype new EIPs.
EELS offers full snapshots of the protocol at every fork—together with upcoming ones—making it a lot simpler to observe than EIPs (which solely suggest modifications) and manufacturing purchasers (which frequently combine a number of forks in the identical codepath.)
Historical past
Starting in 2021, as a mission of ConsenSys’ Quilt group and the Ethereum Basis, the eth1.0-spec (because it was identified then) was impressed by the sheer frustration of getting to decipher the cryptic notation of the Yellow Paper (Figure 1) to know the precise conduct of an EVM instruction.
Drawing on the profitable Consensus Layer Specification, we got down to create an identical executable specification for the execution layer.
Current
At this time, EELS is consumable as a traditional Python repository and as rendered documentation. It is nonetheless a bit tough across the edges, and would not present a lot in the way in which of annotations or English explanations for what numerous items do, however these will include time.
It is simply Python
Hopefully a side-by-side comparability of the Yellow Paper and the equal code from EELS can present why EELS is a beneficial complement to it:
def less_than(evm: Evm) -> None: # STACK left = pop(evm.stack) proper = pop(evm.stack) # GAS charge_gas(evm, GAS_VERY_LOW) # OPERATION end result = U256(left < proper) push(evm.stack, end result) # PROGRAM COUNTER evm.laptop += 1
Whereas Figure 2 is likely to be digestible to teachers, Figure 3 is indisputably extra pure to programmers.
Here is a video walk-through of adding a simple EVM instruction if that is your form of factor.
Writing Assessments
It bears repeating: EELS is simply common Python. It may be examined like some other Python library! Along with all the ethereum/tests suite, we even have a number of pytest exams.
With a little bit assist from execution-spec-tests, any exams written for EELS will also be utilized to manufacturing purchasers!2
Displaying Variations
Having snapshots at every fork is nice for a sensible contract developer popping in to see the specifics of how an EVM instruction works, however is not very useful for consumer builders themselves. For them, EELS can show the variations between forks:
An Instance EIP
EIP-6780 is the primary EIP to get an EELS implementation supplied by the creator, Guillaume Ballet! Let’s have a look.
First, we introduce a created_contracts variable to the EVM with transaction-level scope:
@dataclass class Atmosphere: caller: Handle block_hashes: Checklist[Hash32] origin: Handle coinbase: Handle quantity: Uint base_fee_per_gas: Uint gas_limit: Uint gas_price: Uint time: U256 prev_randao: Bytes32 state: State chain_id: U64 + created_contracts: Set[Address]
Second, we word which contracts had been created in every transaction:
+ evm.env.created_contracts.add(contract_address)
Lastly, we modify selfdestruct so it solely works for contracts famous in created_contracts:
- # register account for deletion - evm.accounts_to_delete.add(originator) - + # Solely proceed if the contract has been created in the identical tx + if originator in evm.env.created_contracts: + + # register account for deletion + evm.accounts_to_delete.add(originator) +
Future
We wish EELS to grow to be the default solution to specify Core EIPs, the primary place EIP authors go to prototype their proposals, and the very best reference for a way Ethereum works.
If you happen to’re eager about contributing or prototyping your EIP, be a part of us on the #specifications channel or seize a difficulty from our repository.
