Final Project: Arithmetic Evaluation

Objectives

During this activity, students should be able to:

Write an expression evaluator using the Clojure programming language.

This activity helps students develop the following skills, values and attitudes: ability to analyze and synthesize, capacity for identifying and solving problems, and efficient use of computer systems.

Activity Description

This project must be developed individually.

The following problem was adapted from: Problem 11326 of the Sphere Online Judge (SPOJ)

Write a Clojure function called arith-eval that evaluates a parenthesized expression of single-digit positive integers and the binary operators +, -, *. The order of operations differs from the canonical one in that operations have no precedence; they are simply evaluated from left-to-right, with only parentheses affecting the order of evaluation.

The arith-eval function should take as an argument a string with the expression to evaluate, and return an integer number as its result. The function should be placed in a name space called final.

Unit tests:

(deftest test-arith-eval
  (is (= 0   (arith-eval "0")))
  (is (= 4   (arith-eval "2+2")))
  (is (= 0   (arith-eval "2-2")))
  (is (= 8   (arith-eval "2*4")))
  (is (= 3   (arith-eval "1*2+1")))    
  (is (= -2  (arith-eval "1-2*2")))
  (is (= 4   (arith-eval "(2+2)")))
  (is (= 8   (arith-eval "(2+(2))*(1+((1)))")))
  (is (= 431 (arith-eval "1+2*3+4-5*6+7*8-9")))
  (is (= 12  (arith-eval "1+((2*3)+4-(5*6)+7)*(8-9)"))))

Deliverables

Using the Online Assignment Delivery System (SETA), deliver a single file called final.clj containing the problem solution and the unit tests. No assignments will be accepted through e-mail or any other means.

IMPORTANT: The program source file must include at the top the authors' personal information (name and student id) within comments. For example:

        
;;; ITESM CEM, May 7, 2012.
;;; Clojure Source File
;;; Final Project: Arithmetic Evaluation
;;; 1166611  Jane Foster

    .
    . (The rest of the program goes here)
    .

Due date: Monday, May 7, 9:00 a.m.

Evaluation

This activity will be evaluated using the following criteria:

-10	The program doesn't contain within comments the authors' personal information.
10	The program contains syntax errors.
DA	The program was plagiarized.
20-50	The program doesn't work, but it seams that some significant amount of time was spent in it.
60-90	The program works, but has some flaws.
100	The program works as requested.

Programming Languages

Final Project: Arithmetic Evaluation

Objectives

Activity Description

Deliverables

Evaluation