ivoire-one-of

Pick items out of a hat. A plugin for the Ivoire random number generator framework.

• Installing
• Getting Started
• Reference
• Acknowledgements

Installing

To install, use npm:

npm install ivoire-one-of

Alternately, you can find the source on Github.

Getting Started

ivoire-one-of extends the ivoire package. You can require it directly:

var Ivoire = require('ivoire-one-of');

Or you can require it alongside ivoire:

var Ivoire = require('ivoire');
require('ivoire-one-of');

Either way, instantiate and start rolling!

var ivoire = new Ivoire();
var one = ivoire.one_of('red', 'blue', 'orange', 'green');

// Cycle through the sequence, returning each item in order and wrapping
// back to the beginning:
one.cycling();

// Cycle through the sequence, returning each item in order until we reach
// the end of the sequence. Continue to return the last item forevermore
// after.
one.stopping();

// Return a random item from the sequence, never returning the
// same item twice in a row.
one.randomly();

// Return a random item from the sequence. May return the same item twice
// or more times in a row!
one.truly_at_random();

// Shuffle the sequence and iterate through, wrapping around to the
// beginning of the shuffled sequence.
one.in_random_order();

Reference

ivoire-one-of adds some methods to the Ivoire prototype object, making them available on all Ivoire instances.

• #one_of()—make a hat for picking items out of it
• one.cycling()—cycle through the items and repeat
• one.stopping()—iterate through and repeat the last
• one.randomly()—pick randomly without repeating
• one.truly_at_random()—pick randomly, with repeats
• one.in_random_order()—cycle through the items in random order and repeat

#one_of()

Syntax

ivoire.one_of(item1[, item2, item3...])

Usage

Return an object with methods for picking items from the provided arguments. The object is cached based on the stringification of the sequence of arguments.

var Ivoire = require('ivoire-one-of');
var ivoire = new Ivoire();

// The returned object will be cached:
var one = ivoire.one_of('red', 'blue', 'green', 'orange');
one.cycling() === 'red';

// When we need the same sequence again (from the same Ivoire instance), the
// same invocation retrieves the cached object and its state.
var another = ivoire.one_of('red', 'blue', 'green', 'orange');
another.cycling() === 'blue';

// If we work off of another Ivoire instance, we get a new cycle.
var ivoire_2 = new Ivoire();
var one_more = ivoire_2.one_of('red', 'blue', 'green', 'orange');
one_more.cycling() === 'red';

The object returned by #one_of() has the following interface:

one.cycling()

Usage

Cycle through the sequence, returning each item in order and wrapping back to the beginning.

var ivoire = new require('ivoire-one-of');
var one = ivoire.one_of('red', 'blue', 'green', 'orange');
one.cycling();

one.stopping()

Usage

Cycle through the sequence, returning each item in order until we reach the end of the sequence. Continue to return the last item forevermore after.

var ivoire = new require('ivoire-one-of');
var one = ivoire.one_of('red', 'blue', 'green', 'orange');
one.cycling();

one.randomly()

Usage

Return a random item from the sequence, never returning the same item twice in a row.

var ivoire = new require('ivoire-one-of');
var one = ivoire.one_of('red', 'blue', 'green', 'orange');
one.randomly();

one.truly_at_random()

Usage

Return a random item from the sequence without filtering repeats. May return the same item twice or more times in a row!

var ivoire = new require('ivoire-one-of');
var one = ivoire.one_of('red', 'blue', 'green', 'orange');
one.truly_at_random();

one.in_random_order()

Usage

Shuffle the sequence of items and iterate through it, one at a time, wrapping around to the beginning of the shuffled sequence. The shuffled order is maintained throughout.

var ivoire = new require('ivoire-one-of');
var one = ivoire.one_of('red', 'blue', 'green', 'orange');
one.in_random_order();

Acknowledgements

The one-of algorithm is based on the implementation in Undum.