Document parser to clarify what exactly is for what

[ethindp]

The parser uses things like masks and matches. From the parsers code, I infer that masks and matches are used for determining what instruction is being (de)coded. I'm writing a RISC-V assembler in Rust that uses this repository to generate all the instruction encoding functions, but I don't know what to set the initial instruction value to (mask or match). How does (en)coding instructions work exactly, assuming I want to use this repository?