A fast immutable lists. Purely functional general purpose replacement for arrays.
Experimental 🚧
Basic functionality is missing. Benchmarks of implemented functions look promising.
- Very good performance
- API centered around functions with arguments ordered for currying/partial application
- Seamless Ramda integration by duplicating their API for arrays
- TypeScript support
- Fantasy Land support
- Full compatibility with tree-shaking. Only pay in size for the functions that you actually use
Implemented: Functor
Not implemented yet: Setoid, semigroup, monoid, apply, applicative, foldable, traversable, chain, monad.
This keeps track of how many of the Ramda functions for Arrays that has currently been implemented on the immutable list: 9/115
adjust, all, any, aperture, append, chain, concat, contains,
drop, dropLast, dropLastWhile, dropRepeats, dropRepeatsWith,
dropWhile, endsWith, filter, find, findIndex, findLast, findLastIndex,
flatten, fromPairs, groupBy, groupWith, head, indexBy, indexOf, init,
insert, insertAll, intersperse, join, last, lastIndexOf,
length, map, mapAccum, mapAccumRight, mergeAll, none, nth,
pair, partition, pluck, prepend, range, reduce, reduceBy,
reduceRight, reduceWhile, reject, remove, repeat, reverse, scan,
sequence, slice, sort, splitAt, splitEvery, splitWhen, startsWith,
tail, take, takeLast, takeLastWhile, takeWhile, times, transpose,
traverse, unfold, uniq, uniqBy, uniqWith, unnest, update, without,
xprod, zip, zipObj, zipWith
Creates a list based on the arguments given.
Complexity: O(n)
Example
const l = list(1, 2, 3, 4); // creates a list of four elements
const l2 = list("foo"); // creates a singletonReturns an empty list.
Complexity: O(1)
Example
const emptyList = empty(); //=> list()Takes two arguments and returns a list that contains them.
Complexity: O(1)
Example
pair("foo", "bar"); //=> list("foo", "bar")Concatenates two lists.
Complexity: O(logn)
Example
concat(list(0, 1, 2), list(3, 4)); //=> list(0, 1, 2, 3, 4)Appends an element to the end of a list and returns the new list.
Complexity: O(logn), practically constant
Example
const newList = append(3, list(0, 1, 2)); //=> list(0, 1, 2, 3)Gets the nth element of the list.
Complexity: O(logn), practically constant
Example
const l = list(0, 1, 2, 3, 4);
nth(2, l); //=> 2Returns a list of numbers between an an inclusive lower bound to an exclusive upper bound.
Complexity: O(n)
Example
range(3, 8); //=> list(3, 4, 5, 6, 7)Returns the length of a list. I.e. the number of elements that it contains.
Complexity: O(1)
Example
length(list(0, 1, 2, 3)); //=> 4Returns the last element of the list. If the list is empty the function returns undefined.
Complexity: O(1)
Example
last(list(0, 1, 2, 3)); //=> 3
last(list()); //=> undefinedApplies a function to each element in the given list and returns a new list with the values that the function return.
Complexity: O(n)
Example
map((n) => n * n, list(0, 1, 2, 3, 4)); //=> list(0, 1, 4, 9, 12)Folds a function over a list.
Aliases: reduce
Complexity: O(n)
Example
foldl((n, m) => n - m, 1, list(2, 3, 4, 5)); //=> -8The benchmarks are located in the bench directory.
Run the benchmarks like this (starting with CWD in the root).
npm install
npm run build
cd bench
npm install
./prepare-benchmarks.sh
npm run bench
Note that in the output List corresponds to @funkia/list.