Char-[ 's', 'e', 'r', 'i', 'e', 's' ]

Just a simple function to generate an array of characters form the given range string. For example "0..9" to generate ["0", "1", "2", ..., "9"]

Importing

The library usages UMD module system so you can use it with any module system of your choice. You can also use it in your html with the <script> tag.

JavaScript

import series from "char-series"; // es module
// or
const series = require("char-series"); // commonjs
// or any other module system that the umd module system supports.

html

<script src="https://unpkg.com/char-series"></script>
<-- It will be available globally by the name "char_series" -->

Usages

The series function takes 4 kinds of argument: string, object, tagged-template, or an array of objects.

series `1..3` // tagged template
series("1..3") // string
series({from: "1", to: "3"}) // object
// all the above function call generates the array ["1", "2", "3"]

series([{from: "1", to: "3"}, {from: "a", to: "c"}]) // object array
// this gives us the array: ["1", "2", "3", "a", "b", "c"]

Note: In html the function name is char_series. So use char_series("1..3").

Argument Types

String Range Syntax

1. "<from>..<to>" gives us all characters from the from(inclusive) character to the to(inclusive) character. e.g., "a..e", "0..9". We can even get a reversed array just by reversing the start and end order. So "c..a" would give us ["c", "b", "a"]
2. <before-count>-<char> gives all the characters starting from before-count characters before the char character and ending at the char character. e.g., "2-c" gives us ["a", "b", "c"]
3. <char>+<after-count> gives all the characters starting from the char character and ending at after-count characters after the char character. e.g., "a+2" gives us ["a", "b", "c"]
4. <before-count>-<char>+<after-count> is the combination of the previous two method. e.g., "2-c+2" gives us ["a", "b", "c", "d", "e"]

Flag: Any series can be reversed by adding a "!r" flag at the end or switching the from to characters order. e.g., "a..c!r" gives us ["c", "b", "a"] and "c..a!r" gives us ["a", "b", "c"].

Series Concatenation for string argument

Two or more series can be concatenated with an "&" character e.g., "0..9&a..z". But this feature gives rise to a problem though! What if we want to see the series "&..'"? It should return us ["&", "'"] but it throws an exception.

So to solve this problem we've to escape the "&" character with a "/" (Notice: It's not a backslash "\") whenever it doesn't represent a delimiter. And then we also have to escape the "/" with another "/" character if we want to write a single "/" character (Ugh 😒)!

Examples:

Un-Escaped and Incorrect	Escaped and Correct
"&..."	"/&..."
"*../"	"*..//"
"a..&&1..5"	"a../&&1..5"
"a..&&1..5&a..c"	"a../&&1..5&a..c"

Object Argument Type

1. {from: char; to: char} e.g., {from: "a", to: "c"}
2. {char: char; before: number} e.g., {char: "c", before: 2}
3. {char: char; after: number} e.g., {char: "a", after: 2}
4. {char: char; before: number; after: number} e.g., {char: "b", before: 1, after: 1}

All the examples above gives us the array ["a", "b", "c"].

Flag: All these objects take an optional {reverse: boolean} property to reverse a series. e.g., {from: "a", to: "c", reverse: true} gives us ["c", "b", "a"] and {from: "c", to: "a", reverse: true} gives us ["a", "b", "c"].

Series Concatenation for object argument

To concatenate tow or more series we can pass an array of series objects, e.g., [{from: "1", to: "3"}, {char: "a", after: 2}] to get the series ["1", "2", "3", "a", "b", "c"].

Examples

const alphanumeric = [...series `0..9`, ...series `a..z`];
// or better if we use series concatenation
const alphanumeric = series `0..9&a..z` // or series("0..9&a..z");
// or 
const alphanumeric = series([{from: "0", to: "9"}, {from: "a", to: "z"}])
/* alphanumeric = [
  '0', '1', '2', '3', '4', '5', '6',
  '7', '8', '9', 'a', 'b', 'c', 'd',
  'e', 'f', 'g', 'h', 'i', 'j', 'k',
  'l', 'm', 'n', 'o', 'p', 'q', 'r',
  's', 't', 'u', 'v', 'w', 'x', 'y',
  'z'
] */

// seems like it works with other languages too :)
const digits_in_bengali = series `০+9` // give us 9 chars after "০"(inclusive)
/* [
  '০', '১', '২', '৩',
  '৪', '৫', '৬', '৭',
  '৮', '৯'
] */

// I wonder what characters are before "0"
const five_chars_before_zero = series({char: "0", before: 5}) // or series `5-0`
/* [ '+', ',', '-', '.', '/', '0' ] */

// 5 characters before "t" and 2 characters after "t" then reverse it
const my_chars = series `5-t+2!r` // or series("5-t+2!r")
//or series({char: "t", before: 5, after: 2, reverse: true})
/* [ 'v', 'u', 't', 's', 'r', 'q', 'p', 'o' ] */

CLI

Yes it also has a cli! Incase you find it useful. But right now it's pretty basic.

# first install it globally or use npx if you prefer
> npm i -g char-series
# see the help text
> series --help

How it works?

Good question! It's really simple :)

function getSeries({ from, to }: {form: number; to: number}) {
  const length = Math.abs(from - to) + 1;

  return from > to
    ? Array.from({ length }, () => String.fromCharCode(from--))
    : Array.from({ length }, () => String.fromCharCode(from++));
}

getSeries({from: "a".charCodeAt(0), to: "c".charCodeAt(0)})
// and we get ["a", "b", "c"]

Finally, let me know if there are any improvements that I can make to this package and kindly give this package a ⭐ on github if you like it :)