numerology
converts a string to a number in the given range
Installation | Examples | Annotated source | License
Installation
npm install numerology
Examples
Name to port number
Convert a name to a port number, deterministically
const numerology = require('numerology')
const userPortsRange = [1024, 49151]
const port = numerology('my-app-name', userPortsRange)
Distribute domains
Suppose you have a list of domains you want to distribute in 6 folders,
in a random but balanced way. You can associate a number from 1 to 6 with
the snippet numerology(domain, [1, 7]), launch the following command
to get the result.
node examples/distributeDomains.js | sort | uniq -c
148 folder1
148 folder2
139 folder3
138 folder4
146 folder5
153 folder6
128 folder7
Annotated source
Latin alphabet system numerology, which actually is not implemented by this package, assigns a number to every lower case latin letter.
The function below uses String.prototype.charCodeAt to accept every character and String.prototype.toLowerCase to be case insensitive.
/**
* @param {String} name you want to convert into a number.
* @param {Array} [range] defaults to `[0, 9]`.
* @returns {Number} num.
*/
function numerology (name, range) {
if (arguments.length === 1) range = [0, 9]
const inf = range[0]
const sup = range[1]
var num = name.split('')
.map((x) => x.toLowerCase().charCodeAt())
.reduce((a, b) => a + b)
if (num < inf) num += inf
if (num > sup) num = (num % sup) + inf
return num
}
module.exports = numerology