teaching machines

CS 330 Lecture 22 – Haskell

March 30, 2016 by Chris Johnson. Filed under cs330, lectures, spring 2016.

Agenda

• what ?s
• exam post mortem
• hello, Haskell
• what we mean by functional
• Haskell examples

TODO

• Read chapters 3 and 4 of Learn You a Haskell for Great Good! On a 1/4 sheet, answer these questions:
  • What’s the type signature of the max function as reported by :t? What does the signature mean?
  • When defining a function with pattern matching, how do you signify that you don’t plan to reference a parameter or a part of a parameter and do not wish to bind it to a name?
  • Write a function clamp and its type signature. It accepts a lower bound, an upper bound, and a value, all Doubles. If the value is in the given range, it returns it without modification. If it’s outside, it returns the appropriate bound.

Note

Today we begin our foray into functional programming. We’ll discuss what is usually meant by the term functional programming. Haskell is a great example of a language that sticks closely to functional ideals, but it’s different enough that we will spend today examining its syntax, function structure, and common data types.

Code

fs.hs

insides :: [a] -> [a]
insides list = tail (init list)