arg_router::utility::utf8 Namespace Reference

Namespaces
	code_point
	no_break_rules

Classes
class	iterator
class	line_iterator

Enumerations
enum class	grapheme_cluster_break_class : std::uint8_t
enum class	line_break_class : std::uint8_t

Functions
std::size_t	levenshtein_distance (std::string_view a, std::string_view b)
template<typename Node >
vector< parsing::token_type >	closest_matching_child_node (const Node &node, parsing::token_type token)
constexpr std::size_t	count (std::string_view str) noexcept
constexpr bool	is_whitespace (std::string_view str) noexcept
constexpr bool	contains_whitespace (std::string_view str) noexcept
constexpr std::size_t	terminal_width (std::string_view str) noexcept

Variables
constexpr auto	double_width_table
constexpr auto	grapheme_cluster_break_table
constexpr auto	line_break_table
constexpr auto	whitespace_table
constexpr auto	zero_width_table

Detailed Description

Namespace for UTF-8 encoded string functions.

Enumeration Type Documentation

grapheme_cluster_break_class

enum arg_router::utility::utf8::grapheme_cluster_break_class : std::uint8_t

strong

Grapheme cluster break classes, and their values in the encoded code points in grapheme_cluster_break_table.

Do not change the order or value as they need to match scripts/unicode_table_generators.py.

Definition at line 18 of file grapheme_cluster_break.hpp.

line_break_class

enum arg_router::utility::utf8::line_break_class : std::uint8_t

strong

Line break classes, and their values in the encoded code points in line_break_table.

Do not change the order or value as they need to match scripts/unicode_table_generators.py.

Definition at line 15 of file line_break.hpp.

Function Documentation

closest_matching_child_node()

template<typename Node >

vector<parsing::token_type> arg_router::utility::utf8::closest_matching_child_node	(	const Node &	node,
		parsing::token_type	token
	)

Uses the Levenshtein distance algorithm to find the closest matching child node to the given token, and it's parents (if any).

Note

This function requires Node to have at least one child

Template Parameters

Node	Parent node type

Parameters

node	Parent node instance
token	Token being queried, the prefix type is considered during the distance calculation

Returns

Closest matching child node token_type and any parents, or an empty vector if all available children are runtime disabled

Definition at line 70 of file levenshtein_distance.hpp.

contains_whitespace()

constexpr bool arg_router::utility::utf8::contains_whitespace ( std::string_view  str )

inlineconstexprnoexcept

Returns true if str contains whitespace.

Parameters

str	Input string

Returns

True if whitespace is present

Definition at line 304 of file utf8.hpp.

count()

constexpr std::size_t arg_router::utility::utf8::count ( std::string_view  str )

inlineconstexprnoexcept

Number of UTF-8 grapheme clusters in the string.

Parameters

str	Input string

Returns

Number of grapheme clusters

Definition at line 278 of file utf8.hpp.

is_whitespace()

constexpr bool arg_router::utility::utf8::is_whitespace ( std::string_view  str )

inlineconstexprnoexcept

True if the leading code point of str is one of the known whitespace characters.

Parameters

str	Code point

Returns

True if whitespace, also false if str is empty or there are not enough bytes in str to read the entire code point

Definition at line 289 of file utf8.hpp.

levenshtein_distance()

std::size_t arg_router::utility::utf8::levenshtein_distance ( std::string_view  a, std::string_view  b  )

inline

Calculates the Levenshtein distance between a and b.

Levenshtein distance gives a measure of similarity between two strings.

Parameters

a	First string
b	Second string

Returns

'Distance' metric as an integer

Definition at line 22 of file levenshtein_distance.hpp.

terminal_width()

constexpr std::size_t arg_router::utility::utf8::terminal_width ( std::string_view  str )

inlineconstexprnoexcept

Returns the terminal width (i.e. number columns) required by str.

This is equivalent to https://www.cl.cam.ac.uk/~mgk25/ucs/wcwidth.c, but constexpr.

Parameters

str	Input string

Returns

Terminal width

Definition at line 321 of file utf8.hpp.

Variable Documentation

double_width_table

constexpr auto arg_router::utility::utf8::double_width_table

constexpr

Double-width code points i.e. those that occupy 2 terminal columns when rendered.

Each entry is an inclusive range of code points.

This table is generated using scripts/unicode_table_generators.py from http://www.unicode.org/Public/UNIDATA/EastAsianWidth.txt v14.0.0.

Definition at line 18 of file double_width.hpp.

grapheme_cluster_break_table

constexpr auto arg_router::utility::utf8::grapheme_cluster_break_table

constexpr

Grapheme cluster break class table.

Each entry is an inclusive range of code points, with each range's break class value encoded as metadata.

This table is generated using scripts/unicode_table_generators.py from https://www.unicode.org/Public/UCD/latest/ucd/auxiliary/GraphemeBreakProperty.txt v14.0.0 and https://www.unicode.org/Public/14.0.0/ucd/emoji/emoji-data.txt v14.0.0

Definition at line 244 of file grapheme_cluster_break.hpp.

line_break_table

constexpr auto arg_router::utility::utf8::line_break_table

constexpr

Line break class table.

Each entry is an inclusive range of code points, with each range's break class value encoded as metadata.

This table is generated using scripts/unicode_table_generators.py from https://www.unicode.org/Public/UCD/latest/ucd/LineBreak.txt v14.0.0

Definition at line 700 of file line_break.hpp.

whitespace_table

constexpr auto arg_router::utility::utf8::whitespace_table

constexpr

Initial value:

= std::array<code_point::range, 11>{{
    {0x000009, 0x00000D},
    {0x000020, 0x000020},
    {0x000085, 0x000085},
    {0x0000A0, 0x0000A0},
    {0x001680, 0x001680},
    {0x002000, 0x00200A},
    {0x002028, 0x002028},
    {0x002029, 0x002029},
    {0x00202F, 0x00202F},
    {0x00205F, 0x00205F},
    {0x003000, 0x003000},
}}

Whitespace code points.

Each entry is an inclusive range of code points.

This table is generated using scripts/unicode_table_generators.py from http://www.unicode.org/Public/UNIDATA/PropList.txt v14.0.0.

Definition at line 18 of file whitespace.hpp.

zero_width_table

constexpr auto arg_router::utility::utf8::zero_width_table

constexpr

Zero-width code points i.e. those that occupy 0 terminal columns when rendered.

Each entry is an inclusive range of code points.

This table is generated using scripts/unicode_table_generators.py from http://www.unicode.org/Public/UNIDATA/extracted/DerivedGeneralCategory.txt v14.0.0.

Definition at line 18 of file zero_width.hpp.