Consider the language
AFun!Exp, which is
AFunExp extended with assignment:
<L> := ...
| (set <id> <L>)
are represented by symbols. Your parser must map this syntax
to values of the following datatype:
(define-datatype AFun!Exp AFun!Exp?
[numE (n number?)]
[funE (var symbol?) (body AFun!Exp?)]
[varE (v symbol?)]
[appE (fun AFun!Exp?) (arg AFun!Exp?)]
[setE (var symbol?) (body AFun!Exp?)])
Write an eager interpreter for
interpreter must model state in the language
without relying on Scheme's implementation of state.
That is, you may not use
set! or boxes or any
other such constructs. You will be penalized for any
violations of the spirit of this assignment, so don't expend
energy trying to find what you think are loopholes (such as
hash-tables, or using external procedures so you can exploit
some other language's implementation of state).
You may assume that programs are closed. Use an environment.
Your interpreter does not need to deal with type
Turn in all the code needed to run programs in
AFun!Exp (parser, interpreter, libraries, etc).
Your code is due by 11am on 2000-09-29. You must also turn in
the test suite you used to validate your solution.
(Each test case in a test suite consists of an input and
its expected output.) Your grade will take into account
the quality of your test cases! Tip: You will find
it useful to add primitives such as
* to the definition of
L to create
better test cases. Include these in your test suite.