Assignment 4

Commands to extract, compile, and run are the same as for the previous assignment.

Assignment

The relevent files for the assignment are:

• mlexer.mll - the specification of the lexical analyzer
• mparser.mly - the specification of the parser
• absyn.ml - contains the grammar for abstract syntax of expressions to be manipulated
• main.ml - the top level
• util.ml - a file with one trivial general function
• Makefile - the makefile
• tests - a few simple test cases
• interpret.ml - contains the beginnings of your solution
• interpret.mli - interface file for your solution
• sinterpret.ml - contains the beginnings of the store-passing solution
• sinterpret.mli - interface file for store-passing solution

This program will evaluate simple scheme expressions. As in the previous assignment, your code will start with the output of the parser. See absyn.ml for the type information of these expressions.

The interface file, interpret.mli, gives the types of the procedures used in interpret.ml. Examine this file, but do not modify it.

For this assignment, you should do the following.

• Finish the code for eval, the static scope interpreter.
• Write the code for set!, set-car!, set-cdr!, and eq?.
• Write a store-passing version of eval.

You may use the solution to the previous assignment to start this assignment.

Submission

Turn in the files interpret.ml and sinterpret on the electronic submission page.