Download is the input, which is a list. Then, you can test your curried function

RYERSON UNIVERSITY
DEPARTMENT OF COMPUTER SCIENCE
CPS506 – Comparative Programming Language
Winter 2010
Assignment 2 – Due: Sunday February 28, 2010
1- Using an example in C++ show that how late binding increases the
flexibility of writing a generic program.
2- By using “Rule of Assignment” and “Rule of Sequence” in Axiomatic
Semantics, and by assuming the provided Q as the post-condition of the
following block of code, find the weakest pre-condition of the block.
P: {?}
s = s +
t = s *
u = t –
Q: {u >
10;
2;
20;
s}
3- Find the loop Invariant and pre-condition of the following while loop
using Axiom rules in Axiomatic Semantics. Is the pre-condition you
found a weakest pre-condition as well? If No, find the weakest precondition of that.
s = 0;
while ( t > 0) {
s = s + t;
t = t – 1;
}
Q: {s > 60}
4- Using signed and unsigned char in C++ as formal parameters write two
overloaded functions, and one or more ambiguous calls to those
functions.
1
5a. Write a generic sort program in Java, such as the ones in Ada (page
60 in the sixth lecture note) and in C++ (page 65 in the sixth lecture
note).
b. Do the same in C#.
For the following questions you need to install Standard ML, using the link
provided in the first lecture note of ML, to write and test your programs.
6- What is the complete and exact result (output) of executing each of the
following commands? (both result value and type)
Example:
~ 1 + 2 - 3 * 4 div 5 mod 6;






val it = ~1 : int
5 + ~7 * 4 div 3;
12.0 / ~9.0 * 2.0 + 1.0;
12.0 / (~9.0 * 2.0) + 1.0;
let val x = 6.5 val y = 3 in x + real y – 0.3 end;
let val (x,y) = (72,72.1) in implode [chr(x),chr(ceil y)] end;
7- Write an ML function to flip the order of each pair inside a list.
Example of the execution of your function could be:
flip [("a",1),("b",2),("c",3)];

[(1,"a"),(2,"b"),(3,"c")]
8- Write an ML function to compute the power of a number.
Example of the execution of your function could be:
power (3,5);

243
2
9- Write an ML function to return the n-th item of a list, as a list containing
that item.
Example of the execution of your function could be:
getItem ([1,4,12,3,9],3);

[12]
10a. Write an ML function to check whether an integer number is even
or not.
Example of the execution of your function could be:
even
even
12; 
5; 
true
false
b. Function you have developed in part a, is called a predicate
function which return true or false according to the input value.
Now, write a curried function to retrieve all the items from a list
satisfying a given predicate function. The signature of the function
could be:
fun span f argument = …
in which f is a predicate function and argument is the input, which is
a list.
Then, you can test your curried function using the even function
that you have written in part a.
Example of the execution of your curried function using even could
be:
span even
[1,2,4,5,7,10,11]; 
[2,4,10]
by which you separate the even numbers from the input list.
c. Using the logic you have used in part b, write another curried
function to create a tuple of two lists, such that the first list contains
all the items from the input list satisfying a given predicate
3
function, and the second list contains the remaining items. The
signature of the function could be:
fun span2 f argument = …
in which f is a predicate function and argument is the input, which is
a list.
Then, you can test your curried function using the even function
that you have written in part a.
Example of the execution of your curried function using even could
be:
span2 even
[1,2,4,5,7,10,11];
4

([2,4,10], [1,5,7,11])