Documentation

Apply f repeatedly until we reach a fixedpoint

Apply a list of functions in succession.

Standard function, returns Just a provided True, and Nothing otherwise

List subset. Surely this must be in a library somewhere.

Interleave a list of lists to a list

Returns Just the tail of a list if it can, and Nothing otherwise.

Returns Just the head of a list if it can, and Nothing otherwise.

Compose functions with one argument with function with two arguments.

f .: g = \x y -> f (g x y).

Finds the unique element in a collection satisfying a predicate. Results in an error if there is no such element or if there are more than one.

>>> iota (== 1) [1, 2, 3]
1

>>> iota (> 1) [1, 2, 3]
*** Exception: iota: expected exactly one element to satisfy the predicate, but found at least two
...

>>> iota (> 3) [1, 2, 3]
*** Exception: iota: expected exactly one element to satisfy the predicate, but found none
...

point moves the (first) element satisfying the predicate to the head of the list. Error raised if no such element found.

>>> point even [1,2,3]
2 :| [1,3]

>>> point even [1,3,5]
*** Exception: point: no such element
...