find package:relude

The find function takes a predicate and a structure and returns the leftmost element of the structure matching the predicate, or Nothing if there is no such element.

Examples

Basic usage:

>>> find (> 42) [0, 5..]
Just 45

>>> find (> 12) [1..7]
Nothing

The bifind function takes a predicate and a structure and returns the leftmost element of the structure matching the predicate, or Nothing if there is no such element.

Examples

Basic usage:

>>> bifind even (27, 53)
Nothing

>>> bifind even (27, 52)
Just 52

>>> bifind even (26, 52)
Just 26

Empty structures always yield Nothing:

>>> bifind even (BiList [] [])
Nothing