diff --git a/guide/english/haskell/list-comprehension/index.md b/guide/english/haskell/list-comprehension/index.md new file mode 100644 index 0000000000..c9484dbbca --- /dev/null +++ b/guide/english/haskell/list-comprehension/index.md @@ -0,0 +1,21 @@ +--- +title: List Comprehensions +--- + +## List Comprehensions + +List comprehensions are a powerful tool in haskell for working with sets. + +```haskell +someNumbers :: [Int] # a list of integers containing, 1, 2 and 3 +someNumbers = [1,2,3] + +allLower :: [Char] +allLower = [toLower c | c <- "Hello, World!" ] + +parity :: [(Int, Boolean)] +parity = [ ( x , even x ) | x <- [1,2,3] ] +``` +Parity produces the following set: `[ (1, False), (2, True), (3, False) ]` + +The right hand side of the list comprehension is composed of two parts; a generator and guards.