/Elixir 1.9

# Range

Defines a range.

A range represents a sequence of one or many, ascending or descending, consecutive integers.

Ranges can be either increasing (`first <= last`) or decreasing (`first > last`). Ranges are also always inclusive.

A range is represented internally as a struct. However, the most common form of creating and matching on ranges is via the `../2` macro, auto-imported from `Kernel`:

```iex> range = 1..3
1..3
iex> first..last = range
iex> first
1
iex> last
3```

A range implements the `Enumerable` protocol, which means functions in the `Enum` module can be used to work with ranges:

```iex> range = 1..10
1..10
iex> Enum.reduce(range, 0, fn i, acc -> i * i + acc end)
385
iex> Enum.count(range)
10
iex> Enum.member?(range, 11)
false
iex> Enum.member?(range, 8)
true```

Such function calls are efficient memory-wise no matter the size of the range. The implementation of the `Enumerable` protocol uses logic based solely on the endpoints and does not materialize the whole list of integers.

# Summary

t()
t(first, last)

## Functions

disjoint?(range1, range2)

Checks if two ranges are disjoint.

new(first, last)

Creates a new range.

# t()

`t() :: %Range{first: integer(), last: integer()}`

# t(first, last)

`t(first, last) :: %Range{first: first, last: last}`

# disjoint?(range1, range2)

(since 1.8.0)
`disjoint?(t(), t()) :: boolean()`

Checks if two ranges are disjoint.

#### Examples

```iex> Range.disjoint?(1..5, 6..9)
true
iex> Range.disjoint?(5..1, 6..9)
true
iex> Range.disjoint?(1..5, 5..9)
false
iex> Range.disjoint?(1..5, 2..7)
false```

# new(first, last)

`new(integer(), integer()) :: t()`

Creates a new range.