Depart ment of Electrical Engineering and Computer Science 6. 001-Structure and Interpret at ion of Computer Programs Spring Semester, 2005 Issued: Tuesday, March 15, 2005 Solut ions due on online tutor: Friday, April 1, 2005 by 6: 00 PM

Department of Electrical Engineering and Computer Science 6.001-Structure and Interpretation of Computer Programs Spring semester, 2005 Project 2-Prisoner's Dilemma

Late homework will not be accepted. In case of illness or absence from MIT make arrangements to complete assignments with your recitation instructor Your TA will examine your project solutions and offer you feedback on them. It's your responsibility to provide clear

Most people learn more effectively when they study in small groups and cooperate in various other ways on homework. This can be particularly true in programming assignments, where working with a partner often helps to avoid careless errors. We are very much in favor of this kind of cooperation, so long as all participants actively involve themselves

Closed book- one sheet of notes hroug hout this quiz, we have set aside space in which you should write your answers. Please try to put all of answers in the designated spaces, as we will look only in this spaces when grading

MASSACHVSETTS INSTITVTE OF TECHNOLOGY epartment of Electrical Engineering and Computer Se lence 001--Structure and Interpretation of Computer Programs Spring Semester, 2005 Quiz I- Sample Solutions

Evaluation and universal machines The Eval/Apply Cycle What is the role of evaluation in defining a language? Eval and Apply execute a cycle that unwinds our abstractions Reduces to simple applications of built in

The 6.001 Lazy Meta-Circular Evaluator The Core Evaluator (define (l-eval exp env) (cond ((self-evaluating? exp) exp) ((variable? exp)(lookup-variable-value exp env)) ((quoted? exp)(text-of-quotation exp)) ((assignment? exp)(eval-assignment exp env)) ((definition? exp)(eval-definition exp env)) ((if? exp)(eval-if exp env))

Slide 17.1.1 Normal Order(Lazy) Evaluation Over the past few lectures, we have been looking at evaluation especially how to implement eval and apply in a anguage such as Scheme, in order to define a language. What we have seen is that by creating, or specifying, eval and its associated procedures, we actually define the semantics of the

Slide 16.1.1 Building up a language Last time, we completed building our evaluator. And as you saw, we slightly misled you. We started off saying we were going to user Scheme's lexical analyzer and parser, but then build our own evaluator, which we did initially for arithmetic