Iterable

Iterable

Value which implements _iterable_ protocol

`iterable/is`

Confirms if given object is an _iterable_ and is not a _string_ (unless `allowString` option is passed)

```javascript

const isIterable = require("type/iterable/is");

isIterable([]); // true

isIterable({}); // false

isIterable("foo"); // false

isIterable("foo", { allowString: true }); // true

```

Supports also `denyEmpty` option

```javascript

isIterable([], { denyEmpty: true }); // false

isIterable(["foo"], { denyEmpty: true }); // true

```

`iterable/ensure`

If given argument is an _iterable_, it is returned back. Otherwise `TypeError` is thrown.

By default _string_ primitives are rejected unless `allowString` option is passed.

```javascript

const ensureIterable = require("type/iterable/ensure");

ensureIterable([]); // []

ensureIterable("foo", { allowString: true }); // "foo"

ensureIterable({}); // Thrown TypeError: null is not expected iterable

```

Denying empty iterables

Pass `denyEmpty` option to require non empty iterables

```javascript

ensureIterable([], { denyEmpty: true }); // Thrown TypeError: [] is not expected iterable

```

Confirming on items

Items can be validated by passing `ensureItem` option. Note that in this case:

• A newly created instance of array with coerced values is returned
• Error message lists up to three invalid items

```javascript

const ensureString = require("type/string/ensure");

ensureIterable(new Set(["foo", 12]), { ensureItem: ensureString }); // ["foo", "12"]

/*

Below invocation with crash with:

TypeError: [object Set] is not expected iterable value.

Following items are invalid:

- [object Object]

*/

ensureIterable(new Set(["foo", {}]), { ensureItem: ensureString });

```