Fe is an emerging smart contract language for the Ethereum blockchain.
NOTE: The larger part of the master
branch will be replaced with the brand-new implementation, which is currently under development in the fe-v2 branch. Please refer to the branch if you kindly contribute to Fe
Fe is a statically typed language for the Ethereum Virtual Machine (EVM). It is inspired by Rust and easy to learn -- especially for new developers entering the Ethereum ecosystem.
Additional information about design goals and background can be found in the official announcement.
We aim to provide a full language specification that should eventually be used to formally verify the correctness of the compiler. A work in progress draft of the specification can be found here.
Fe development is still in its early stages. We have a basic Roadmap for 2021 that we want to follow. We generally try to drive the development by working through real world use cases. Our next goal is to provide a working Uniswap implementation in Fe which will help us to advance and form the language.
Fe had its first alpha release January 2021 and is now following a monthly release cycle.
To compile Fe code:
fe path/to/fe_source.fe
output
in the current working directory that contains the compiled binary and abi.Run fe --help
to explore further options.
The following is a simple contract implemented in Fe.
struct Signed {
pub book_msg: String<100>
}
contract GuestBook {
messages: Map<address, String<100>>
pub fn sign(mut self, mut ctx: Context, book_msg: String<100>) {
self.messages[ctx.msg_sender()] = book_msg
ctx.emit(Signed(book_msg: book_msg))
}
pub fn get_msg(self, addr: address) -> String<100> {
return self.messages[addr].to_mem()
}
}
A lot more working examples can be found in our test fixtures directory.
The most advanced example that we can provide at this point is an implementation of the Uniswap-V2 core contracts.
The Fe implementation is split into several crates. Crates that depend on the
solidity compiler (directly or indirectly) are licensed GPL-3.0-or-later. This
includes the fe
CLI tool, yulc, driver, tests, and test-utils.
The remaining crates are licensed Apache-2.0. This includes the parser, analyzer, mir, abi, and common.