Package Exports

ranging
ranging/range.js
ranging/range.mjs

This package does not declare an exports field, so the exports above have been automatically detected and optimized by JSPM instead. If any package subpath is missing, it is recommended to post an issue to the original package (ranging) to support the "exports" field. If that is not possible, create a JSPM override to customize the exports field for this package.

Readme

ranging (JavaScript library)

Range helper classes based on iterators

Installation

Using npm:

npm install ranging

Using yarn:

yarn add ranging

Examples

Importing

const { NumberRange, StringRange } = require('ranging');
// ES
import { NumberRange, StringRange } from 'ranging';

Typescript support (only v1.1.0+)

There is support for TS with a specification higher than ES5

Number ranges

Integers

A list of integers from 1 to 10 inclusive

const { NumberRange } = require('ranging');

// it's same as
const sameIntegers = [...new NumberRange({ start: 1, end: 10 })];

Integers ranged with step of 2

const integers = [
  ...new NumberRange({
    start: 1,
    end: 10,
    step: 2
  })
];
// integers: [ 1, 3, 5, 7, 9 ]

Floating point numbers

let floats = [
  ...new NumberRange({
    start: 2,
    end: 5,
    step: 0.5,
    float: true
  })
];
console.log(floats);
// [ 2, 2.5, 3, 3.5, 4, 4.5, 5 ]

floats = [
  ...new NumberRange({
    start: 2,
    end: 5,
    float: true
  })
];
console.log(floats);
// [ 2, 3, 4, 5 ]

Note: sum fractional floating point numbers with NumberRange.sum.
Approximation error

let sum = 0;
for (let i = 1; i <= 20; i++) {
  sum += i / 10;
}
console.log(sum);
// 20.999999999999996

Use of NumberRange.sum (expected answer)

console.log(
 new NumberRange({
    start: 0.1,
    end: 2,
    step: 0.1
  }).sum
);
// 21

Infinite generator

Use of NumberRange without specifying end

let counter = 0;
const result = [];

for (let i of new NumberRange({ start: 1005 })) {
  const hex = i.toString(16);
  if (hex == hex.split('').reverse().join('')) {
    counter++;
    result.unshift(i);
  }
  if (counter === 10) break;
}
console.log(result);
// [ 1156, 1140, 1124, 1108, 1092, 1076, 1060, 1044, 1028, 1011 ]

Starting from 1005, executes until finds 10 numbers that are palindromes in hexadecimal notation. The result is presented in descending order.

Char Ranges

const { CharRange } = require('ranging');

console.log([
  ...new CharRange()
]);
// [ 'A', ..., 'Z' ]

Simillary, you can use options like step, count and etc.

console.log([
  ...new CharRange({
    start: 'a',
    end: 'f',
    step: 2
  })
]);
// [ 'a', 'c', 'e' ]

String Ranges

Iteration over a passed string

const { StringRange } = require('ranging');

console.log([
  ...new StringRange({ source: 'Hello world' })
])
// ['H', 'e', 'l', 'l', 'o', ' ', 'w', 'o', 'r', 'l', 'd']

console.log([
  ...new StringRange({
    source: 'Hello world',
    start: 6,
    step: 2
  })
])
// [ ' ', 'o', 'l' ]

Date Ranges

Simple Date Range

const { DateRange } = require('ranging');

console.log([
  ...new DateRange({
    start: new Date(),
    count: 5, // if given, overrides `step`
    step: 5
  })
])

// [
//   2021-08-18T09:23:55.670Z,
//   2021-08-18T09:23:55.675Z,
//   2021-08-18T09:23:55.680Z,
//   2021-08-18T09:23:55.685Z,
//   2021-08-18T09:23:55.690Z
// ]

Other time units

You can use various time units, such as SecondRange, MinuteRange and etc.

const { YearRange } = require('ranging');

console.log([
  ...new YearRange({
    step: 1,
    leepYear: true,
    count: 10
  })
])

// [
//   2024-08-18T09:34:01.866Z,
//   2028-08-18T09:34:01.866Z,
//   2032-08-18T09:34:01.866Z,
//   2036-08-18T09:34:01.866Z,
//   2040-08-18T09:34:01.866Z
// ]

Less known solutions

Color Range

const { ColorRange } = require('ranging');

console.log(...new ColorRange({ end: '#00000F' }));
// #000000 #000001 #000002 #000003 #000004 #000005 #000006 #000007 #000008 #000009 #00000a #00000b #00000c #00000d #00000e #00000f

Merging ranges

Glue ranges together.

const { NumberRange, CharRange, MergeRanges } = require('./range');

const numbers = new NumberRange({ end: 5 });
const chars = new CharRange({ end: 'D' });

const merging = new MergeRanges({ ranges: [numbers, chars] });

console.log(...merging);
// 0 1 2 3 4 5 A B C D

Combining (zipping) ranges

Works as the known function from other programming languages.

const { NumberRange, CharRange, ZipRanges } = require('./range');

const numbers = new NumberRange({ start: 1 });
const chars = new CharRange({ end: 'D' });

const zipped = new ZipRanges({ keys: chars, values: numbers });

console.log(...zipped);
// {'A': 1}
// {'B': 2}
// {'C': 3}
// {'D': 4}

// or
console.log(zipped.ranged);
// {
//   'A': 1,
//   'B': 2,
//   'C': 3,
//   'D': 4
// }

Note: numbers is set up as an infinite iterator, but zipping it with chars limits it to just 4 entries.

Range Functions

Map

const { StringRange } = require('ranging');

const word = new StringRange({
  source: 'Crypted.',
  map: (x) => String.fromCharCode(x.charCodeAt(0) + 1)
});

console.log([...word].join(''))
// Dszqufe/

Filter

const { NumberRange } = require('ranging');

const someSeq = new NumberRange({
  start: 10,
  end: 40,
  filter: (item) => item % 3 === 0 && item % 5 === 0
});

console.log([...someSeq]);
// [ 15, 30 ]

Reduce

const { StringRange } = require('ranging');

const word = new StringRange({
  source: 'Some bad word',
  map: (item) => (item === ' ' ? item : 'x')
});

console.log(word.reduce((prevValue, currValue) => prevValue + currValue, ''))
// xxxx xxx xxxx

Length

const { NumberRange } = require('ranging');

const someSeq = new NumberRange({ end: 9 });

console.log(someSeq.length);
// 9

Sum (only `NumberRange`)

const { NumberRange } = require('ranging');

console.log(
  new NumberRange({
    start: 0.1,
    end: 2,
    step: 0.1,
    float: true
  }).sum
);
// 21

ranging