Unicode Guards

Provides a set of function guards that can be used to match Unicode codepoints. Based upon ex_unicode and unicode_set.

Usage

Each guard operates on a UTF8 codepoint since the permitted operators in a guard clause are restricted to simple comparisons that do not include strings.

The data that underpins these guards is generated from the Unicode character database and therefore includes a broad range of scripts well beyond the basic ASCII definitions.

Some examples follow defining functions using the pre-defined guards. Note that since guards operate on codepoints (not strings) we use binary pattern matching to extract the first codepoint for these example.

defmodule Guards do
  import Unicode.Guards

  def upper(<< x :: utf8, _rest :: binary >>) when is_upper(x), do: :upper
  def lower(<< x :: utf8, _rest :: binary >>) when is_lower(x), do: :lower
  def digit(<< x :: utf8, _rest :: binary >>) when is_digit(x), do: :digit
  def whitespace(<< x :: utf8, _rest :: binary >>) when is_whitespace(x), do: :whitespace
  def currency(<< x :: utf8, _rest :: binary >>) when is_currency_symbol(x), do: :currency
end

Installation

The package can be installed by adding unicode_guards to your list of dependencies in mix.exs:

def deps do
  [
    {:unicode_guards, "~> 1.0"}
  ]
end

The docs can be found at https://hexdocs.pm/unicode_guards.