The Diom Programming language

This is mostly a language written because:

1. I haven't written a compiler in a while
2. I wanted to give it a go in rust :P
3. I wanted to give a language with minimal syntax a go
4. I like expression-driven languages but don't want to be stuck with FP
5. I've gotten interested in Algebraic effects

Todo

• Tidy up all imports to use super -> crate -> ...

Syntax

• Prevent multiple Rest patterns from being used in Tuples and Structs
  This can be acheived by, instead of allowing any item to be Rest pattern
  only allowing the last item to be one and using an Option<Rest> property
  within the Struct and Tuple.
• Merge the Array and Tuple patterns (they're the same at this point...)
• We currently only use Path nodes for pattern matching, why?
• Convert monad nodes and parsing to use Algebraic effects

Parsing

• f-string support
  • I'll need to update how strings are parsed...
  • maybe consider having f-strings create templates not strings
    if we support string conversion on these, we can solve most
    of the standard string injection attacks by not converting to
    strings until the last possible second.
• fix all bugs uncovered by property testing (3 so far)
  and add equivalent regression tests for each encountered issue.
• property testing on AST -> code -> AST round trip
  • implement Display for AST
  • implement generators for ASTs
  • add property testing
• use nom-language's precedence parser

Formatting

• add a custom formatting for creating boxes
• pretty printing ASTs (formatting)
• add a custom formatter for indented structures
• printing ASTs as code

Interpreter

• add function calls
• add regression tests for bugs encountered during use (0 so far)

Documentation

• Ensure docstrings are present on all syntax nodes
• Add simple docstrings to parsers that mention what they parse