readme: updated todo

README.md

@@ -9,14 +9,11 @@ prompt. Work in progress. Very incapable right now.
 
 The idea behind `bc` is to display partial results to the right of the
 cursor in yellow while we type. A little example can be found in the video
-above. Other than that, we want to be compatible with the original `bc`, though
-somewhat faster. We have infinite precision integers and double precision floats.
+above. Minor syntactic cleanups have been developed as well (e.g. no `local`
+keyword). We have infinite precision integers and double precision floats.
 
 ## TODO
 
-Basically everything except numbers, variables, and `if`. This includes:
-
-- A complete parser (foundations are laid)
-- A better evaluator (the current just does a tree rewrite on binary operations; this is
-  cute, but not capable enough for the full `bc` language, of course)
 - A good readline copy (haskeline is sadly out of the question for this project)
+- Comment parsing
+- Closures that can modify the parent environment (but do away with the `local` keyword).