uutils AWK progress report

[Alonely0]

I will be updating this issue as we make progress. Please feel free to take down good first issues here and in the issue tracker.

Interpreter Tasklist

• Regex automaton memoization.
• String/num value memoization.
• for-each loops. May be complicated to get right due to the configurable order, so I'm putting it off a bit.
• Record splitting modes of FPAT and single-byte naïve memchr.
• getline instructions, proper print/print redirections.
• General I/O in the event loop and VM dispatch.
• Wire in lexer/parser in the interpreter for robust indirect call parsing + built-in funs disambiguation, libloaded funs disambiguation.
• Built-in vars auto-setting.
• Maybe custom instructions for SYMTAB-, FUNCTAB-, PROCINFO-related operations because they're probably too magical, and emulating them as plain arrays would probably be too costly anyway.
• Range patterns.
• Etc.

Various

• Some parser differentials I've got written down and should get to fixing. God I hate AWK's grammar.
• More robust --pretty-printing, with more precedence disambiguation and default args expansion for built-ins.
• Support in for lookups of arrays of arrays (trivial-ish).
• Library loading (via libloading) and C/FFI function calls.
• Debugger.
• Get clap to behave properly.
• Sanity.