# `Unicode.NumericValue`
[🔗](https://github.com/elixir-unicode/unicode/blob/v2.2.0/lib/unicode/property/numeric_value.ex#L1)

Functions to introspect the Unicode `Numeric_Value` property for binaries (Strings) and codepoints.

The `Numeric_Value` property is the numeric value a codepoint represents. Whole numbers are returned as integers and fractions as a `{numerator, denominator}` tuple. Codepoints with no numeric value return `nil`.

The primary API is `numeric_value/1` which returns the numeric value of a codepoint, or the list of numeric values of a string. See `Unicode.NumericType` for the associated numeric type.

# `value`

```elixir
@type value() :: integer() | {integer(), integer()} | nil
```

A Unicode numeric value: an integer, a `{numerator, denominator}` fraction, or `nil`.

# `aliases`

Returns an empty map.

The `Numeric_Value` property has no value aliases; this function exists to satisfy the `Unicode.Property.Behaviour`.

### Returns

* An empty map.

### Examples

    iex> Unicode.NumericValue.aliases()
    %{}

# `count`

Returns the count of the codepoints having a given numeric value.

### Arguments

* `value` is an integer or `{numerator, denominator}` tuple.

### Returns

* A non-negative integer count of the codepoints with the value.

* `:error` if no codepoint has the value.

### Examples

    iex> Unicode.NumericValue.count(7) > 0
    true

# `fetch`

Returns the Unicode codepoint ranges having a given numeric value.

### Arguments

* `value` is an integer or `{numerator, denominator}` tuple.

### Returns

* `{:ok, range_list}` where `range_list` is a list of codepoint ranges as 2-tuples.

* `:error` if no codepoint has the value.

### Examples

    iex> Unicode.NumericValue.fetch(7) |> elem(0)
    :ok

    iex> Unicode.NumericValue.fetch(:invalid)
    :error

# `get`

Returns the Unicode codepoint ranges having a given numeric value.

### Arguments

* `value` is an integer or `{numerator, denominator}` tuple.

### Returns

* A list of codepoint ranges as 2-tuples.

* `nil` if no codepoint has the value.

### Examples

    iex> Unicode.NumericValue.get(:invalid)
    nil

# `known_numeric_values`

Returns a list of known Unicode numeric values.

### Returns

* A list of integers and `{numerator, denominator}` tuples.

### Examples

    iex> 7 in Unicode.NumericValue.known_numeric_values()
    true

    iex> {1, 2} in Unicode.NumericValue.known_numeric_values()
    true

# `numeric_value`

```elixir
@spec numeric_value(String.t()) :: [value(), ...]
@spec numeric_value(Unicode.codepoint()) :: value()
```

Returns the numeric value of the given binary or codepoint.

### Arguments

* `string_or_codepoint` is either a binary (String) or a codepoint in the range `0..0x10FFFF`.

### Returns

* For a codepoint, the numeric value as an integer, a `{numerator, denominator}` tuple, or `nil` if the codepoint has no numeric value.

* For a binary, a list of the distinct numeric values of the codepoints in the binary is returned.

### Examples

    iex> Unicode.NumericValue.numeric_value(?7)
    7

    iex> Unicode.NumericValue.numeric_value(?½)
    {1, 2}

    iex> Unicode.NumericValue.numeric_value(?A)
    nil

# `numeric_values`

Returns the map of Unicode numeric values.

### Returns

* A map where the numeric value (an integer or `{numerator, denominator}` tuple) is the key and a list of codepoint ranges as 2-tuples is the value.

### Examples

    iex> Unicode.NumericValue.numeric_values() |> Map.get(7) |> Enum.any?(fn {first, last} -> ?7 in first..last end)
    true

---

*Consult [api-reference.md](api-reference.md) for complete listing*