@kingjs/tokenizer NPM

@kingjs/tokenizer

Generates arrays of odometer digits.

Usage

A typical car odometer has 7 wheels, each wheel has 10 digits, and a new value is generated as the car moves along. These values can be generated like this:

var Odometer = require('@kingjs/odometer')

var odometer = new Odometer(10, 10, 10, 10, 10, 10, 10);

var enumerator = odometer.getEnumerator();

var actual = [];
for (var distance = 0; distance < 11; distance++) { // 11 is arbitrary
  generator.moveNext();
  var current = generator.current;
  actual.push(current.reverse());
}

actual;

outputs:

[
  [0, 0, 0, 0, 0, 0, 0],
  [0, 0, 0, 0, 0, 0, 1],
  [0, 0, 0, 0, 0, 0, 2],
  [0, 0, 0, 0, 0, 0, 3],
  [0, 0, 0, 0, 0, 0, 4],
  [0, 0, 0, 0, 0, 0, 5],
  [0, 0, 0, 0, 0, 0, 6],
  [0, 0, 0, 0, 0, 0, 7],
  [0, 0, 0, 0, 0, 0, 8],
  [0, 0, 0, 0, 0, 0, 9],
  [0, 0, 0, 0, 0, 1, 0],
];

API

function odometer(bases?: number[]): {
  getEnumerator: {
    (): {
      moveNext: { (): Boolean },
      current: number[]
    }
  }
}

Parameters

bases: an array of normal numbers (or as an argument list) specifying the number of "digits" on each wheel of the odometer at each position.

Return Value

A generator of arrays containing the digits produced by an odometer of the specified number of digits and bases. The generator terminates after every combination has been generated.

Remarks

A typical odometer increments digits from right to left. This odometer increments from left to right (which is why the example calls Array.reverse()). This is done so digits increment starting at index 0.

Install

With npm installed, run

$ npm install @kingjs/odometer

Acknowledgments

fromEach was inspired by nUnit ValuesAttribute and TheoryAttribute which use an odometer to generate combinations of test values from a set of arrays.