Haskell Types

Built-in Types

Chapter 2 in Learn You a Haskell ....

• Basic types: Int, Integer, Float, Double, Bool, Char
  • Usual numeric and comparison operators, e.g., +, -,*, /, <, <=, etc.
  • Exponentiation operator: r^2 is r²
  • Integer is an unbounded integer (can be as big as you want)
  • Boolean constants and operators:    True    False     &&    ||     not     ==    /=
  • Character constants are in single quotes, e.g., 'a'


• Lists - homogenous, any length
  • List constructors:    [1, 2, 3]    1 : [2, 3]
  • "hello" is short-hand for ['h', 'e', 'l', 'l', 'o']
  • Haskell supports series, infinite lists, lazy evaluation, list comprehension, generators, e.g.,

       [1, 2 .. 5]
       [1, 2 .. ]
       [ n * n * n | n <- [1 .. 10]

  • Many list operators & functions, e.g., ++, !!, length, head, tail, reverse, zip


• Tuples: heterogeneous, fixed size
  • Tuple constructors use parentheses:    [ ("COMP230", "Computer Organization", 27), ("COMP320", "Programming Languages", 23) ]