Unicode.BidiClass (Unicode v2.0.0)

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Functions to introspect the Unicode bidirectional (bidi) class property for binaries (Strings) and codepoints.

The primary API is bidi_class/1 which returns the bidi class of a codepoint, or the list of bidi classes of a string.

The functions fetch/1, get/1 and count/1 provide introspection of the codepoint ranges belonging to a bidi class. bidi_classes/0, known_bidi_classes/0 and aliases/0 return the underlying bidi class data.

Summary

Functions

aliases()

Returns a map of aliases for Unicode bidi classes.

bidi_class(string)

Returns the bidi class name(s) for the given binary or codepoint.

bidi_classes()

Returns the map of Unicode bidi classes.

count(bidi_class)

Returns the count of characters in a given bidi class.

fetch(bidi_class)

Returns the Unicode codepoint ranges for a given bidi class.

get(bidi_class)

Returns the Unicode codepoint ranges for a given bidi class.

known_bidi_classes()

Returns a list of known Unicode bidi class names.

Functions

aliases()

Returns a map of aliases for Unicode bidi classes.

An alias is an alternative name for referring to a bidi class. Aliases are resolved by the fetch/1 and get/1 functions.

Returns

  • A map where the alias string is the key and the bidi class name is the value.

Examples

iex> Unicode.BidiClass.aliases() |> Map.get("arabicletter")
:al

bidi_class(string)

Returns the bidi class name(s) for 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, a single bidi class name is returned.

  • For a binary, a list of the distinct bidi class names of the codepoints in the binary is returned.

Examples

iex> Unicode.BidiClass.bidi_class(?A)
:l

iex> Unicode.BidiClass.bidi_class(0x05D0)
:r

iex> Unicode.BidiClass.bidi_class(0x0627)
:al

iex> Unicode.BidiClass.bidi_class("abc")
[:l]

bidi_classes()

Returns the map of Unicode bidi classes.

Returns

  • A map where the bidi class name is the key and a list of codepoint ranges as 2-tuples is the value.

Examples

iex> Unicode.BidiClass.bidi_classes() |> Map.get(:lre)
[{8234, 8234}]

count(bidi_class)

Returns the count of characters in a given bidi class.

Aliases are resolved by this function.

Arguments

  • bidi_class is any bidi class name or alias, as an atom or string.

Returns

  • A non-negative integer count of the codepoints in the bidi class.

  • :error if the bidi class is not known.

Examples

iex> Unicode.BidiClass.count(:al)
1478

fetch(bidi_class)

Returns the Unicode codepoint ranges for a given bidi class.

Aliases are resolved by this function.

Arguments

  • bidi_class is any bidi class name or alias, as an atom or string.

Returns

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

  • :error if the bidi class is not known.

Examples

iex> Unicode.BidiClass.fetch(:lre)
{:ok, [{8234, 8234}]}

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

get(bidi_class)

Returns the Unicode codepoint ranges for a given bidi class.

Aliases are resolved by this function.

Arguments

  • bidi_class is any bidi class name or alias, as an atom or string.

Returns

  • A list of codepoint ranges as 2-tuples.

  • nil if the bidi class is not known.

Examples

iex> Unicode.BidiClass.get(:lre)
[{8234, 8234}]

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

known_bidi_classes()

Returns a list of known Unicode bidi class names.

This function does not return the names of any class aliases.

Returns

  • A list of atom bidi class names.

Examples

iex> :l in Unicode.BidiClass.known_bidi_classes()
true