Difference between revisions of "Cookbook/Compilers and interpreters"

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(first step to turn this page from an arbitrary tutorial to a cookbook chapter)
(Checking Types)
Line 10: Line 10:
Prelude> :t "Hello"
Prelude> :t "Hello"
"Hello" :: [Char]
"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

Revision as of 08:11, 31 August 2009



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]