listutils

The listutils.fn namespace in the fn/ directory contains basic functions for dealing with lists. It can be included by link "listutils.fn" as list; in the let section of your source file.

At the time of writing it includes the following functions.

Name	Type	Description
member(item, lst)	#a -> list(#a) -> bool	true if the first argument is a member of the second argument list.
exclude(list, lst)	list(#t) -> list(#t) -> list(#t)	returns the second argument list minus any elements on the first argument list.
map(function, lst)	(#a -> #b) -> list(#a) -> list(#b)	Applies the first argument function to each element of the second argument list and returns a list of the results.
length(lst)	list(#s) -> number	Returns the length of the argument list.
foldl(fn, acc, lst)	(#a -> #b -> #b) -> #b -> list(#a) -> #b	Example: foldl(fn (a, b) { a + b }, 0, [1, 2, 3]) will add up all of the elements of the list.
foldr(fn, acc, lst)	(#a -> #b -> #b) -> #b -> list(#a) -> #b	Same as foldl but starts at the end of the list and works backwards.
foldl1(fn, lst)	(#a -> #a -> #a) -> list(#a) -> #a	Like foldl but uses the first item on the list as the initial value.
foldr1(fn, lst)	(#a -> #a -> #a) -> list(#a) -> #a	Like foldl1 but from the right like foldr.
reverse(lst)	list(#a) -> list(#a)	Returns the reverse of its argument list.
scanl(fn, acc, lst)	(#a -> #b -> #b) -> #a-> list(#a) -> list(list(#b))	like foldl but returns a list of the intermediate values.
filter(fn, lst)	(#a -> bool) list(#a) -> list(#a)	applies its first argument function to each item on its second argument list and returns a list of those items for which the function returned true.
concat(list(lst))	list(list(#a)) -> list(#a)	Combines its argument list of lists into a single list.
join(lst, list(lst))	list(#a) -> list(list(#a)) -> list(#a)	Like concat but interpolates its first argument between each element of its second.
any(fn, lst)	(#a -> bool) -> list(#a) -> bool	Returns true if its argument function returns true for any elements of the list.
none(fn, lst)	(#a -> bool) -> list(#a) -> bool	Returns true only if its argument function returns false for every element of the list.
all(fn, lst)	(#a -> bool) -> list(#a) -> bool	Returns true only if its argument function returns true for every element of the list.
repeat(n, item)	number -> #a -> list(#a)	Example repeat(5, 'x'); // "xxxxx"
nth(n, lst)	number -> list(#a) -> #a	Returns the nth element of the list.
sum(lst)	list(number) -> number	adds up all of the elements of the list
product(lst)	list(number) -> number	multiplies all of the elements of the list.
zip(lst, lst)	list(#a) -> list(#b) -> list(#(#a, #b))	Pairs each element of its first argument list with the corresponding element of the second argument list, returns a list of those pairs (tuples).
zipwith(fn, lst, lst)	(#a -> #b -> #c) -> list(#a) -> list(#b) -> list(#c)	Like zip but takes a third argument function to do the combining.
last(lst)	list(#a) -> #a	Returns the last element of the argument list.
empty(lst)	list(#a) -> bool Returns true if the argument list is empty.
take(n, lst)	number -> list(#a) -> list(#a)	Returns the first n items from the list.
drop(n, lst)	number -> list(#a) -> list(#a)	Returns all but the first n elements of the list.
minimum(lst)	list(#a) -> #a	Returns the smallest element on the list.
maximum(lst)	list(#a) -> #a	Returns the largest element on the list.
range(n, n)	number -> number -> list(number)	Returns a list of numbers from low to high, inclusive.
dedup(lst)	list(#a) -> list(#a)	returns the unique elements of the argument list.
sortBy(fn, lst)	(#a -> #a -> cmp) -> list(#a) -> list(#a)	Takes a comparison function and uses it to sort the list.
sort(lst)	list(#a) -> list(#a)	Sorts the list using the standard <=> operator.

Next: Anb Utils.