Tokenize words.
Add basic token types other than words.
Break into modules and parse basic terms.
Add error messages.
Add type signature.
Separate definitions from terms.
Clean up error handling.
Ignore dotfiles and backups.
Resolve words to definition indices.
Make name resolution typesafe.
Fix warnings.
Lint.
Add rudiments of type inference.
Resolve and type lambdas.
Resolve and type definitions.
Associate names with type schemes instead of types.
Remove repetition and dead code.
Change vector and function delimiters.
Clean up and document.
Require program to begin with empty stack.