itbl

itbl

Source:

Classes

_Wrapper

Methods

(static) combine(collection, finishopt) → {itbl._Wrapper}

Combines the iterables in collection into a single iterable containing collections of values from each iterable in collection.

collection can either be an Iterable or an object containing Iterables which will be combined. The first value in the combined Iterable will be an Iterable or an object containing the first values of the Iterables in collection, the second value containing the second values of the Iterables in collection and so on.

The value of finish determines when the iteration ends.

  • If finish === 'early' or 'e' (default) then the iteration ends as soon as the first iterator from collection ends.

  • If finish === 'late' or 'l' then the iteration continues untill all iterators from collection are done. Values corresponding to iterators that have ended are undefined.

  • If finish === 'together' or 't' then all iterators from collection must finish on the same iteration or else an Error is thrown.

Note: The return value of the iterator is a collection of the of the return values the iterators from collection. Return values corresponding to iterators that have not yet ended are undefined

combine is particularly powerful when used with es6 destructuring assignment.

Parameters:
Name Type Attributes Default Description
collection Iterable | Object

Collection of iterators
finish string <optional>
 'early'

Flag determining when iteration will finish.
Since:
  • 0.1.0
Source:
Returns:

Iterable containing collection of values

Type
itbl._Wrapper
Example
let mySet = new Set();
mySet.add(1);
mySet.add(Math);

[...itbl.combine([['a','b','c'], mySet, ['alpha','beta', 'gamma']])];
// -> [['a', 1, 'alpha'], ['b', Math, 'beta']]

// with `finish === late`
[...itbl.combine([['a','b','c'], ['alpha','beta', 'gamma'], mySet], 'late')];
// [['a', 1, 'alpha'], ['b', Math, 'beta'], ['c', undefined, 'gamma']]

let coordinates = itbl.combine({
  x: [1,2,3,4,5],
  y: [1,4,9,16,25],
});

for(let coor of coordinates) {
  context.lineTo(coor.x, coor.y);
}

// more concise syntax using object destructuring
for(let {x, y} of coordinates) {
  context.lineTo(x,y);
}

(static) filter(iterable, predicateopt) → {itbl._Wrapper}

Creates a new iterable containing values which the predicate returns truthy for.

Parameters:
Name Type Attributes Default Description
iterable Iterable

Iterable to filter the values of.
predicate function <optional>
 _.identity

Function to run each value though.
Since:
  • 0.1.0
Source:
Throws:

Throws an error if iterators are not supported or the iterable is not iterable.

Type
Error
Returns:

iterable filtered using predicate, if iterable was an iterator then an iterator is returned, otherwise an iterable is returned.

Type
itbl._Wrapper
Example
[...itbl.filter([0,1,2,3,4,5], val => val%2 === 0)];
// [0,2,4]

let mySet = new Set().add(1).add('a').add(NaN);

[...itbl.filter(mySet, value => _.isFinite)];
// [1]

var users = [
  { 'user': 'barney', 'age': 36, 'active': true },
  { 'user': 'fred',   'age': 40, 'active': false }
];

[...itbl.filter(users, function(o) { return !o.active; })];
// => objects for ['fred']

[...itbl.filter(users, _.matches({ 'age': 36, 'active': true }))];
// => objects for ['barney']

[...itbl.filter(users, _.matchesProperty('active', false))];
// => objects for ['fred']

[...itbl.filter(users, _.property('active'))];
// => objects for ['barney']

(static) isIterable(value) → {boolean}

Checks if value is an iterable object according to es6 iterator protocols. In order to be iterable, an object must implement the @@iterator method, meaning that the object (or one of the objects up its prototype chain) must have a property with a [Symbol.iterator] key which defines a function. (https://developer.mozilla.org/en/docs/Web/JavaScript/Reference/Iteration_protocols#iterable)

Parameters:
Name Type Description
value *

The value to check.
Since:
  • 0.1.0
Source:
Returns:

Returns true if value is correctly classified, else false.

Type
boolean
Example
function MyIterable() { }

MyIterable.prototype[Symbol.iterator] = function*(){
  while(true) yield 1;
}

let iterableInstance = new MyIterable();

itbl.isIterable(iterableInstance);
// => true

// generator function that is then called
itbl.isIterable(iterableInstance[Symbol.iterator]());
// => true (this is both an iterator and also iterable)

itbl.isIterable([1, 2, 3]);
// => true

itbl.isIterable({1: 1, 2: 2, 3: 3});
// => false

(static) isIterator(value) → {boolean}

Checks if value is an iterator according to es6 iterator protocols. An object is an iterator when it implements a next() method. See https://developer.mozilla.org/en/docs/Web/JavaScript/Reference/Iteration_protocols#iterator for more information.

Parameters:
Name Type Description
value *

The value to check.
Since:
  • 0.1.0
Source:
Returns:

Returns true if value is correctly classified, else false.

Type
boolean
Example
function MyIterable() { }

MyIterable.prototype[Symbol.iterator] = function*() {
  while(true) yield 1;
};

let iterableInstance = new MyIterable();

itbl.isIterator(iterableInstance);
// => false (this is an iterable but NOT an iterator)

// generator function that is then called
itbl.isIterator(iterableInstance[Symbol.iterator]());
// => true (this is both an iterator and also iterable)

itbl.isIterator([1, 2, 3][Symbol.iterator]());
// => true

for(let i of ['a'])
  itbl.isIterator(i)
// => false (i is equal to 'a')

(static) map(iterable, iterateeopt) → {itbl._Wrapper}

Creates a new iterable whose iterators will have values corresponding to the value of the Iterator of the original iterable run through iteratee. The iteratee is invoked with only one argument (value).

Parameters:
Name Type Attributes Default Description
iterable Iterable

Iterable to map values of.
iteratee function <optional>
 _.identity

Function to run each value though.
Since:
  • 0.1.0
Source:
Throws:

Throws an error if iterable is not iterable.

Type
Error
Returns:

iterable mapped through iteratee, if iterable was an iterator then an iterator is returned, otherwise an iterable is returned.

Type
itbl._Wrapper
Example
for(let coor of itbl.map([0, 1, 2, 3, 4, 5], x => ({ x, y: Math.exp(x) }))) {
  context.lineTo(coor.x, coor.y);
}

let mySet = new Set().add(1).add('a').add(NaN);

[...itbl.map(mySet, value => value + 1)];
// [2, 'a1', NaN]

var users = [
  { 'user': 'barney' },
  { 'user': 'fred' },
];

[...itbl.map(users, _.property('user'))];
// => ['barney', 'fred']

(static) noConflict() → {itbl}

Reverts the itbl variable to its previous value and returns a reference to the itbl function.

Since:
  • 2.0.0
Source:
Returns:

Returns the itbl function.

Type
itbl
Example
var IterableUtil = itbl.noConflict();

Type Definitions

Step

Type:
  • Object
Source: