seqtools

Efficient utilities for sequence.

Background
Install
Usage
- head
- tail
- init
- last
- headTail
- initLast
API
Contributing
License

Background

This project is a sequence version of itertools.

It provides the most efficient solution for sequence.

A sequence is an “indexable, sliceable data structure”. See Sequence for the specific interface.

Standard data structures that satisfy this are string and array.

These data structures encompass multiple data and require efficient data processing. However, in many cases, multiple alternatives exist to accomplish the same thing.

If you do something similar, you can always use this project. In general, index access and slicing are performance optimal.

Install

deno.land:

import * as mod from "https://deno.land/x/seqtools/[snake_case].ts";

npm:

npm i @miyauci/seqtools

Usage

mod.ts does not exist.

head

Extract the first element of a sequence.

import { head } from "https://deno.land/x/seqtools/head.ts";
import { assertEquals } from "https://deno.land/std/testing/asserts.ts";

assertEquals(head([1, 2, 3]), 1);
assertEquals(head("abc"), "a");
assertEquals(head([]), undefined);

tail

Extract the elements after the head of a sequence.

import { tail } from "https://deno.land/x/seqtools/tail.ts";
import { assertEquals } from "https://deno.land/std/testing/asserts.ts";

assertEquals(tail([1, 2, 3]), [2, 3]);
assertEquals(tail("abc"), "bc");
assertEquals(tail([0]), []);
assertEquals(tail([]), []);

init

Extract the elements before the last of a sequence.

import { init } from "https://deno.land/x/seqtools/init.ts";
import { assertEquals } from "https://deno.land/std/testing/asserts.ts";

assertEquals(init([1, 2, 3]), [1, 2]);
assertEquals(init("abc"), "ab");
assertEquals(init([0]), []);
assertEquals(init([]), []);

last

Extract the last element of a sequence.

import { last } from "https://deno.land/x/seqtools/last.ts";
import { assertEquals } from "https://deno.land/std/testing/asserts.ts";

assertEquals(last([1, 2, 3]), 3);
assertEquals(last("abc"), "c");
assertEquals(last([]), undefined);

headTail

Split the sequence into head and tail.

import { headTail } from "https://deno.land/x/seqtools/head_tail.ts";
import { assertEquals } from "https://deno.land/std/testing/asserts.ts";

assertEquals(headTail([1, 2, 3]), [1, [2, 3]]);
assertEquals(headTail("abc"), ["a", "bc"]);
assertEquals(headTail([]), [undefined, []]);

initLast

Split the sequence into init and last.

import { initLast } from "https://deno.land/x/seqtools/init_last.ts";
import { assertEquals } from "https://deno.land/std/testing/asserts.ts";

assertEquals(initLast([1, 2, 3]), [[1, 2], 3]);
assertEquals(initLast("abc"), ["ab", "c"]);
assertEquals(initLast([]), [[], undefined]);