TODO

• [] add options by dumping loading and dumping json before and after each task
• [] add subset operations to topological sort \
• [] generalize topological sort
• [] convert patterns into each-other, i.e. ".txt" -> ".csv"
• [] add glob v. regex v. filename recognizer to grammar
• [] convert globs to regexes
• [] python integration with clojure/scala, via json protocol or via jython/jepp. Only needed really for parsing && post-parsing
• [] consider eval'ing in a sandbox
• [] fix bash variables to be $OUT1, $OUT2 etc.

Maybes

• [] support Maybe[input]