tl;dr
- EELS is an execution layer reference implementation in Python.
- It is updated with mainnet.
- It fills assessments, and passes current ones.
- There’s an instance of an EIP applied in EELS beneath.
Introduction
After greater than a yr in growth, we’re happy to publicly introduce the Ethereum Execution Layer Specification (affectionately referred to as EELS.) EELS is a Python reference implementation of the core parts of an Ethereum execution shopper centered 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 assessments, comply with mainnet1, and is a good 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 comply with than EIPs (which solely suggest adjustments) and manufacturing purchasers (which regularly combine a number of forks in the identical codepath.)
Historical past
Starting in 2021, as a venture of ConsenSys’ Quilt group and the Ethereum Basis, the eth1.0-spec (because it was recognized then) was impressed by the sheer frustration of getting to decipher the cryptic notation of the Yellow Paper (Figure 1) to grasp the precise 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 traditional Python repository and as rendered documentation. It is nonetheless a bit tough across the edges, and does not present a lot in the way in which 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 invaluable 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.computer += 1
Whereas Figure 2 could be digestible to lecturers, Figure 3 is indisputably extra pure to programmers.
This is a video walk-through of adding a simple EVM instruction if that is your form of factor.
Writing Exams
It bears repeating: EELS is simply common Python. It may be examined like another Python library! Along with your complete ethereum/tests suite, we even have a number of pytest assessments.
With a little bit assist from execution-spec-tests, any assessments written for EELS will also be utilized to manufacturing purchasers!2
Exhibiting 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 Atmosphere: caller: Tackle block_hashes: Record[Hash32] origin: Tackle coinbase: Tackle 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 be aware which contracts have 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 turn into the default strategy to specify Core EIPs, the primary place EIP authors go to prototype their proposals, and the absolute best reference for the way Ethereum works.
In the event you’re involved in contributing or prototyping your EIP, be a part of us on the #specifications channel or seize a problem from our repository.
