Since these types were written, we've gained an executable spec:
https://github.com/ethereum/execution-specs
This PR aligns some of the types we use with this spec to simplify
comparisons and cross-referencing.
Using a `distinct` type is a tradeoff between nim ergonomics, type
safety and the ability to work around nim quirks and stdlib weaknesses.
In particular, it allows us to overload common functions such as `hash`
with correct and performant versions as well as maintain control over
string conversions etc at the cost of a little bit of ceremony when
instantiating them.
Apart from distinct byte types, `Hash32`, is introduced in lieu of the
existing `Hash256`, again aligning this commonly used type with the spec
which picks bytes rather than bits in the name.
We don't need to clear keccak context after hashing ethereum data since
it is already public - similar to
https://github.com/status-im/nimbus-eth2/pull/222.
Because we overwrite the result fully, we also don't need to zero first.
`eth_types` is being imported from many projects and ends up causing
long build times due to its extensive import lists - this PR starts
cleaning some of that up by moving the chain DB and RLP to their own
modules.
this PR also moves `keccakHash` to its own module and uses it in many
places.
Jacek Sieka
tersec