Whitespace tidying.
Organise todos.
Improve type assertion's error message.
Factor out isVariadicSymbol.
Negative numbers.
Remove jsArrayToTesloArray, as it is a noop.
Update TODO.
Code tidying.
Don't blow up on falsey values.
Add a todo.
Node repl fixes.
Add a todo.
Structure Symbols & Keywords like regular data types.