# CPF

A library to work with CPFs.

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CPF is an acronym for "Cadastro de Pessoa Físicas," it's a unique number
associated with a person that the Brazilian government maintains. With this number,
it is possible to check if a person has any irregularity on tax payments, if they
are alive and many other status that are provided from Brazilian government services
or private company services.

This library provides a validation that checks if the number is a valid CPF
number. The CPF has check digit algorithm is similar to
[`ISBN 10`](https://en.wikipedia.org/wiki/Check_digit#ISBN_10), you can check
the details in Portuguese [here](https://pt.wikipedia.org/wiki/Cadastro_de_pessoas_f%C3%ADsicas#C%C3%A1lculo_do_d%C3%ADgito_verificador).

## Installation

If [available in Hex](https://hex.pm/docs/publish), the package can be installed
by adding `cpf` to your list of dependencies in `mix.exs`:

```elixir
def deps do
  [
    {:cpf, "~> 0.2.0"}
  ]
end
```

## Quick Start

You verify if the CPF is valid by calling the function `CPF.valid?/1`:

```elixir
iex> CPF.valid?(563_606_676_73)
true

iex> CPF.valid?(563_606_676_72)
false

iex> CPF.valid?("563.606.676-73")
true

iex> CPF.valid?("563.606.676-72")
false

iex> CPF.valid?("56360667673")
true

iex> CPF.valid?("56360667672")
false
```

## Why not other libraries?

This library runs 3 times faster and consume 3 times less memory and work with
primitive types, no extra struct is necessary.

## Docs

The docs can be found at [https://hexdocs.pm/cpf](https://hexdocs.pm/cpf).