Here is one in Haskell which is more complete: https://github.com/mit-plv/riscv-semantics https://github.com/mit-plv/riscv-semantics. For example, it supports 6

Here is one in Haskell which is more complete: https://github.com/mit-plv/riscv-semantics https://github.com/mit-plv/riscv-semantics. For example, it supports 64-bit ISA while this one doesn't yet.