closures, upvalues
good repl
arrays, hashes, other useful types
	arrays:
		get index
		set index
		get length
		literals
		append
		concat
		conformation of at least arithmetic over arrays
	hashes:
		get index
		set index
		get count
		literals
		merge?
		delete?
		should probably implement ht with keys other than strings
	user-defined structs, somehow, maybe
good loops
	numeric for
	array for each
	functional variants of the above
	variants of the above that record an array of all their results
pattern matching
	probably doesn't need to be too complex
garbage collector
	go thru everything make sure references are kept around properly
macros
error handling
	record line and col of everything
	not sure how to do error handling in language but at least
		make the error messages good
	more sophisticated testing of errors
		instead of just literally matching error message
tidy and clean the code
	properly do bounds checking everywhere etc