Cookbook/Compilers and interpreters

Checking Types

To check the type of an expression or function, use the command `:t'

Prelude> :t x
x :: Integer
Prelude> :t "Hello"
"Hello" :: [Char]

Haskell has the following types defined in the Prelude.

    Int         -- bounded, word-sized integers
    Integer     -- unbounded integers
    Double      -- floating point values
    Char        -- characters
    String      -- equivalent to [Char], strings are lists of characters
    ()          -- the unit type
    Bool        -- booleans
    [a]         -- lists
    (a,b)       -- tuples / product types
    Either a b  -- sum types
    Maybe a     -- optional values