# Sets

Operators and functions for working with an array of boolean values (**set** type) are described here.

* [arr( set s ) arr.int](#arr-set-s-arr-int)
* [set( arr.int a ) set](#set-arr-int-a-set)
* [set( str s ) set](#set-str-s-set)
* [str( set s ) str](#str-set-s-str)
* [Set( set s, int index ) set](#set-set-s-int-index-set)
* [Toggle( set s, int index ) bool](#toggle-set-s-int-index-bool)
* [UnSet( set s, int index ) set](#unset-set-s-int-index-set)

## Operators

| Operator             | Result | Description                                                                                |
| -------------------- | ------ | ------------------------------------------------------------------------------------------ |
| **\*** set           | int    | Returns the set size.                                                                      |
| **^** set            | set    | Returns a new set as logical NOT of the source set. *!s\[i]* for each item.                |
| set **=** set        | set    | Assignment operator.                                                                       |
| set **&=** set       | set    | Create a clone of the set. The new variable will work with the same data set.              |
| set **+=** set       | set    | Appends a set to a set variable.                                                           |
| set **&** set        | set    | Returns a set that is the intersection of two sets. *left\[i] && right\[i]* for each item. |
| set **\|** set       | set    | Returns a set that is the union of two sets. *left\[i] \|\| right\[i]* for each item.      |
| set **\[** int **]** | bool   | Sets/gets a set value.                                                                     |

## Functions

### arr(set s) arr.int

The *arr* function converts a *set* value to an array of integers that contains indexes of *set* items.

### set(str s) set

The *set* function converts a string to a *set* value and returns it. The string must only have 1 and 0 characters.

### set(arr.int a) set

The *set* function converts an array of integers to a *set* value and returns it. The result set will have items with corresponding indexes.

```
run arr.int {
  set s &= {780, 99, 128, 105, 136}
  arr.int as = arr(s)
  as += 330
  s &= set(as)
  return arr(s) // [99 105 128 136 330 780]
}
```

### str(set s) str

The *str* function converts a *set* value to a string and returns it. The result string contains only 1 and 0.

### Set(set s, int index) set

The *Set* function adds an index item to the set. It is the same as *s\[index] = true*. The function returns *s*.

### Toggle(set s, int index) bool

The *Toggle* function adds an index item to the set if the set doesn't have it and otherwise, the function removes the item. It is the same as *s\[index] = !s\[index]*. The function returns the previous state - *true* if the item existed and, otherwise, false.

### UnSet(set s, int index) set

The *UnSet* function removes an index item from the set. It is the same as *s\[index] = false*. The function returns *s*.