CS440 Programming Languages - Midterm Exam - Part 3: Interpreter modifications
CS 440 Midterm Exam (Take-Home)
This midterm exam consists of 7 separate exercises --- 3 on recursion and lists, 3 on higher order functions, and 1 involving an addition to an interpreter. They are described below:
Part 3: Interpreter modifications
For this part you will add a case expression to the same interpreter provided for MP2. A
case expression has the following form:
(case TEST-EXPR [INT-VAL1 EXPR1] [INT-VAL2 EXPR2] ...
[else ELSE-EXPR])
The TEST-EXPR is first evaluated, and its result is compared to the various INT-VALs --- if one matches, the corresponding EXPR is evaluated and becomes the result of the case expressions. If none of the INT-VALs match, the ELSE-EXPR is evaluated.
E.g.,
> (case 1 [1 10] [3 20] [5 30]
[else 40]) 10
> (case (+ 2 3) [1 (* 2 3)] [3 (+ 3 4)]
[5 (* 2 (+ 3 8))]
[else (+ 30 10)])))) 22
●
You may choose to implement the case statement either by desugaring it to if expressions or by modifying the eval function directly. If you choose to use desugaring, feel free to reuse your code from MP2.
Get the Solution to This Question
WeChat (微信)
WhatsApp
