tl;dr
- EELS is an execution layer reference implementation in Python.
- It is updated with mainnet.
- It fills checks, and passes present ones.
- There’s an instance of an EIP carried out in EELS beneath.
Introduction
After greater than a yr in improvement, 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 parts of an Ethereum execution shopper targeted on readability and readability. Meant as a non secular successor to the Yellow Paper that is extra programmer pleasant and up-to-date with post-merge forks, EELS can fill and execute state checks, observe mainnet1, and is a superb place to prototype new EIPs.
EELS supplies 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 shoppers (which regularly combine a number of forks in the identical codepath.)
Historical past
Starting in 2021, as a challenge of ConsenSys’ Quilt staff 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 (Determine 1) to grasp the particular habits 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 conventional Python repository and as rendered documentation. It is nonetheless a bit tough across the edges, and would not present a lot in the best way of annotations or English explanations for what varied 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 priceless 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 consequence = U256(left proper) push(evm.stack, consequence) # PROGRAM COUNTER evm.computer += 1
Whereas Determine 2 may be digestible to teachers, Determine 3 is indisputably extra pure to programmers.
This is a video walk-through of including a easy EVM instruction if that is your type of factor.
Writing Exams
It bears repeating: EELS is simply common Python. It may be examined like another Python library! Along with all the ethereum/checks suite, we even have a number of pytest checks.
With a bit of assist from execution-spec-tests, any checks written for EELS can be utilized to manufacturing shoppers!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 shopper 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 offered 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 Surroundings: caller: Handle block_hashes: Record[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 notice 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 would like EELS to develop into the default approach to specify Core EIPs, the primary place EIP authors go to prototype their proposals, and the absolute best reference for a way Ethereum works.
If you happen to’re fascinated about contributing or prototyping your EIP, be a part of us on the #specs channel or seize a difficulty from our repository.
