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Types
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Take
What are the types of the following Haskell expressions. Try to think what they might be before checking with the Haskell interpreter.
(a) (*)
(b) (&&) True
(c) \x -> \f -> f (f x) (d) tail [1,2,3]
(e) error
(f) \(x,y) -> x&&True
Lists and Pattern Matching
Write a function equal in Haskell syntax that takes two lists of elements (where each element has a type that is an instance of the Eq class) and checks whether they are equal (i.e., returns True if they have exactly the same elements in the same order, False otherwise). Give the most general (polymorphic) type for equal.
Write a Haskell function to reverse a list. For example: rev [1,2,3] should give [3,2,1].
Using equal and rev write a function palindrome that checks whether a list is a palindrome. A list is a palindrome if the list is the same in reverse. The lists [1,0,0,1], [True, False, True] and [0,1,2,3,3,2,1,0] are examples of palindromes.
Data types
Using the definition of binary tree from Exercise sheet 3, write a function mapTree that will apply a function to all the node elements of the tree.
If you have time
a look at the extra questions that you can find on: http://users.sussex.ac.uk/~im74/G6021/.
G6021: Comparative Programming
Exercise Sheet 5
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