hevm VS containers

hevm - written in Haskel

However, since we are using a pure Solidity stack, writing tests with ds-test and running them with dapp.tools or foundry, this was a bit more complicated.

There's also jshon which is a simple stack-based DSL for constructing JSON from shell scripts.

http://kmkeen.com/jshon/

It's written in C and is not actively developed. The latest commit, it seems, was a pull request from me back in 2018 that fixed a null-termination issue that led to memory corruption.

Because I couldn't rely on jshon being correct, I rewrote it in Haskell here:

https://github.com/dapphub/dapptools/tree/master/src/jays

This is also not developed actively but it's a single simple ~200 line Haskell program.

It fits into the stack the same way that Hardhat, Truffle, and Dapp Tools do.

I find it insane that much of Solidity code testing is still happening in external languages. I've recently found https://github.com/dapphub/dapptools and that has blown a lot of my confusion away.

Honourable mention would be https://github.com/dapphub/dapptools for those who prefer UNIX-like tooling, but I'd say for the most part Foundry seems to be the better choice now.

Firstly, I'm warning you that I'm going to shill some amazing things in the Ethereum ecosystem. I would even go so far to say as some of these things are so positive sum and self-evidently public goods that shilling them in the ethereum subreddit should be considered neutral. For example, GitcoinDAO is a place where we all have the permissionless ability to coordinate in building tools and services, like dapptools, for all open-source software, full stop. There's ways to fundraise in public besides joining Discord or sliding into Twitter DM's, like Juicebox. There is a plethora of industry leaders exploring decentralized hosting for bluechip-scale applications, such as Skynet.

If you're into CLI tools - https://dapp.tools/

Dapptools is another framework that has nothing to do with JavaScript.

"Make invalid laziness unrepresentable" means you should use strict versions of container types instead of lazy ones. However, for better or for worse, sometimes the "strict version" of a data type is not actually a strict data type, it's just a strict API to the lazy type. Examples include Data.Map.Strict (not Data.Map or Data.Map.Lazy) or Data.HashMap.Strict (not Data.HashMap.Lazy) (sadly there is no Data.Sequence.Strict but perhaps there will be one day).

Indeed it's rather subtle. See https://github.com/haskell/containers/issues/752 for more discussion on the matter. Nonetheless, I believe it is "spine strict" in the sense that thunks for all values always exist, even if the spine that holds them can be rearranged due to laziness.

Note that the list index operator has O(n) complexity. Ideally you'd want to use something like Seq from the containers package

Edison and containers both have sequence types that support efficient, cons, snoc, viewL, viewR, append, map, and length.

containers

Calling linked lists Haskell's "primary data structure" seems off-base to me. Yes, there's String, yes, there's built-in syntax for List... but there's also everything in containers, and vector is pretty easy to use in practice, though it would probably be good for more learning material to mention it more prominently.

Haskell has much more sophisticated immutable data structures, you can find them in the "containers" package: https://hackage.haskell.org/package/containers

I asked this on the libraries mailing list but thought posting here would bring in potentially more responses. I made a recent change to the behaviour of lookup and find (see here for more details: https://github.com/haskell/containers/pull/800).

Rust has nothing on Haskell. containers, which might as well be considered part of the standard library, has been out for almost 14 years and is still 0.x