Interpreter implementing the denotational semantics of the While language, as defined in Chapter 4 of the book Semantics With Applications: A Formal Introduction.
Start by running
ghci while.hsParse a program, given as a string
parse <parser> <program>
-- returns all possible parses as a list of (String, Stm) tuplesEvaluate the final state of a program
eval <program>Check the value of a variable at the end of the program
value <var> <program>Only single letters ('a' - 'z') can be used as variable names.
