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 beneath.
Introduction
After greater than a 12 months 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 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 superb place to prototype new EIPs.
EELS gives full snapshots of the protocol at every fork—together with upcoming ones—making it a lot simpler to observe 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 challenge of ConsenSys’ Quilt staff 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 (Determine 1) to grasp the precise habits of an EVM instruction.
Drawing on the profitable Consensus Layer Specification, we got down to create the same executable specification for the execution layer.
Current
Right now, EELS is consumable as a standard 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 precious complement to it:
# 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.
Here is a video walk-through of including a easy EVM instruction if that is your type of factor.
Writing Checks
It bears repeating: EELS is simply common Python. It may be examined like another Python library! Along with the complete ethereum/exams suite, we even have a number of pytest exams.
With a bit assist from execution-spec-tests, any exams written for EELS may also be utilized to manufacturing purchasers!2
Exhibiting Variations
Having snapshots at every fork is nice for a wise 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:
class Surroundings:
caller: Tackle
block_hashes: Checklist[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 had been created in every transaction:
Lastly, we modify selfdestruct so it solely works for contracts famous in created_contracts:
– 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 out to be the default option to specify Core EIPs, the primary place EIP authors go to prototype their proposals, and the absolute best reference for the way Ethereum works.
Should you’re occupied with contributing or prototyping your EIP, be part of us on the #specs channel or seize a problem from our repository.
