#### `set(object, path, value, delimiter)`
 - `import { set } from 'perfect-immutable'`
 - works similar to lodash's `_.set()` or Immutable.js `set()` and `setIn()` but does not mutate the object and accepts plain JS object or array (can be used to easily, immutably set value in complicated nested structure)
 - arguments:
   - **object**: *object|array* object or array to set value in
   - **path**: *string|assignmentsObject* path to the value you want to change, can be deep e.g. 'field.subField.somethingElse'. Can be an object e.g. { 'field.subField': 'newValue', 'anotherField.anotherSubField': 'anotherNewValue' } Lodash's array like syntax is also supported (e.g. 'field\[1\].subField')
   - **value**: *any* value to be set in the path (if path is an object *value* is ignored)
 - returns **newObject**

#### `splice(array, start, deleteCount[, ...items])`
- `import { splice } from 'perfect-immutable'`
- works like array.prototype.splice but creates new array instead of mutating existing one
- arguments:
    - **array**: *array* source array
    - **start**: *number* zero-based index at which to start changing the array
    - **deleteCount**: *number* an integer indicating the number of old array elements to remove
    - **items**: *any* (optional) the elements to add to the array, beginning at the `start` index
- returns **newArray**

#### `push(array, ...items)`
- `import { push } from 'perfect-immutable'`
- works like array.prototype.push but creates new array with added entries instead of mutating existing one
- arguments:
    - **array**: *array* source array
    - **items**: *any* the elements to add to the array
- returns **newArray**

#### `pop(array)`
- `import { pop } from 'perfect-immutable'`
- works like array.prototype.pop but creates new array with last element removed
- arguments:
    - **array**: *array* source array
- returns **newArray**

#### `shift(array)`
- `import { shift } from 'perfect-immutable'`
- works like array.prototype.shift but creates new array with first element removed
- arguments:
    - **array**: *array* source array
- returns **newArray**

#### `unshift(array, ...items)`
- `import { unshift } from 'perfect-immutable'`
- returns new array with items added at the beginning
- arguments:
    - **array**: *array* source array
    - **items**: *any* the elements to add to the beginning of an array, will appear in the array in the same order in which they were passed to the function
- returns **newArray**

#### `sort(array, compareFunction)`
- `import { sort } from 'perfect-immutable'`
- Returns new, sorted array without mutating the source
- arguments:
    - **array**: *array* source array
    - **compareFunction**: *function* function to compare arrays values
- returns **newArray**

#### `reverse(array)`
- `import { reverse } from 'perfect-immutable'`
- works like array.prototype.reverse but creates new, reversed array
- arguments:
    - **array**: *array* source array
- returns **newArray**

#### `immutableDelete(source, index)`
- `import { immutableDelete } from 'perfect-immutable'`
- creates new array or object with one element removed
- arguments:
    - **source**: *array|object* source array or object
    - **index**: *number|string* index of element to be removed
- returns **newArrayOfObject**

#### `filter(source, predicate)`
- `import { filter } from 'perfect-immutable';`
- creates new array or object with elements predicate returned truthy for (is just a wrapper for lodash [filter](https://lodash.com/docs/4.17.4#filter) and can be used the same way
- arguments:
   - **source**: *array|object* source array
   - **predicate**: *function|object|array|string* function invoked per iteration (see lodash filter documentation)