CS217 Assignment 4 Due Monday, April 24, 2000

CS217 Assignment 4, Due Monday, April 24, 2000

Submit assgn4.scm by hsp.
The file must contain at least your name and a comment before each problem, indicating its number and other info you feel is required.

Environment Passing Interpreters

Start with interp3-1.scm which

loads dj.scm
loads sllgen.scm
contains environment from pp 51-56
program and expression data types from pp64-65
interpreter from Fib 3.1, p66
parse- and unparse- expression, program
the 3-1 grammar, specified on pp67-68
Extending definitions of expression, primitive, parse-expression and the grammar as necessary, do

Ex 3.2.3, p70: Add the primitive minus
Ex 3.2.4, p70: Add the primitive print
Ex 3.2.5, p70: Add list primitives cons, car, cdr, list, and a variable emptylist with value ().
Ex 3.3.1, p72: Add and test the if form.
Ex 3.3.2, p72: Add numeric equality, zero-testing and order predicates equal?, zero?, greater? and less?.
Ex 3.3.3, p72: Add the primitive null?.
Ex 3.4.1, p75: Add and test the let form (Fig 3.2, p74).
Ex 3.5.1, p80: Add and test the proc form (Fig 3.3, p 78).

assgn4.scm must be loadable into Scheme and procedures must pass tests of correctness.