libucd

This library extends the inbuilt char type with the Codepoint trait, which implements 100 properties of the UCD (Unicode Character Database). It aims to be fast and compact, and to have minimal dependencies (it does not require the rust standard library so only needs rust's core crate).

extern crate ucd;
use ucd::Codepoint;

fn main() {
    let salawat: char = 'ﷺ';
    let decomp: String = salawat.decomposition_map().collect();
    println!("{} -> {}", salawat, decomp);
    // ﷺ -> صلى الله عليه وسلم
}

Though the library is fairly extensive, it is not complete. The properties it lacks are:

• Character names and aliases
• Unihan properties
• Tangut source data
• Named sequences
• Standardised variants
• CJK Radicals
• Emoji source data

Data was compressed as arrays of ranges of codepoints having each value for each property, excluding the most common value. Lookup is then implemented by a binary search which should provide O(1) access. A very unscientific test suggests each lookup takes around 100ns on a core i5 processor.

Disclaimer

Please note that this data has been derived from the flat XML version of the UCD. Though this is published by Unicode, it is not the official version of the database. As such, it cannot be guaranteed that this library is entirely consistent with the official database. The unit tests do however suggest consistency with the XML database at least.

Reference

Note, in most cases enum values are simply the full name of the property value converted to camelcase. Perhaps I will eventually create a rustdoc version that will be more helpful.

In the tables below, the first column is the name of the property, and the second column is the method name. The methods are implemented via the ucd::Codepoint trait on char.

General	Method	Return Type	Note
Age	age	Option<(u8,u8)>	Return None if the character is unassigned, else a tuple of major and minor age
Block	block	Option<UnicodeBlock>
General_Category	category	UnicodeCategory	Return Unassigned if unassigned
ISO_Comment (deprecated, stabilized)	iso_comment	&str	All characters are null, i.e. "" is returned

Function and Appearance	Method	Return Type	Note
Alphabetic	Codepoint::is_alphabetic or is_alpha	bool	Rust's char already defines a method is_alphabetic which shadows this implementation and provides slightly different results (possibly by using an outdated version of the UCD). Use the namespace, or the is_alpha alias instead.
ASCII_Hex_Digit	is_hex_digit_ascii	bool
Dash	is_dash	bool
Default_Ignorable_Code_Point	is_default_ignorable	bool
Deprecated	is_deprecated	bool
Diacritic	is_diacritic	bool
Extender	is_extender	bool
Hex_Digit	is_hex_digit	bool
Hyphen (deprecated, stabilized)	is_hyphen	bool
Logical_Order_Exception	is_logical_order_exception	bool
Math	is_math	bool
Noncharacter_Code_Point	is_noncharacter	bool
Other_Alphabetic	is_alphabetic_other	bool
Other_Default_Ignorable_Code_Point	is_default_ignorable_other	bool
Other_Math	is_math_other	bool
Prepended_Concatenation_Mark	is_prepended_concatentation_mark	bool
Quotation_Mark	is_quotation_mark	bool
Sentence_Terminal	is_sentence_terminal	bool
Soft_Dotted	is_soft_dotted	bool
Terminal_Punctuation	is_terminal_punctuation	bool
Variation_Selector	is_variation_selector	bool
White_Space	Codepoint::is_whitespace or is_white	bool	Again, char shadows this with its own implementation so use the namespace or alias.

Numeric	Method	Return Type	Note
Numeric_Type	numeric_type	Option<NumericType>
Numeric_Value	numeric_value	Option<Number>	The Number type is an enum of Integer(i64) and Rational(i32,u32), to cover values as large as 10^12 and as small as 1/160.

Identifiers and Syntax	Method	Return Type	Note
ID_Continue	is_id_continue	bool
ID_Start	is_id_start	bool
Other_ID_Continue	is_id_continue_other	bool
Other_ID_Start	is_id_start_other	bool
Pattern_Syntax	is_pattern_syntax	bool
Pattern_White_Space	is_pattern_whitespace	bool
XID_Continue	is_id_continue_nfkc	bool
XID_Start	is_id_start_nfkc	bool

Scripts	Method	Return Type	Note
East_Asian_Width	east_asian_width	EastAsianWidth
Hangul_Syllable_Type	hangul_syllable_type	Option<HangulSyllableType>
Ideographic	is_ideograph	bool
IDS_Binary_Operator	is_ideograph_description_sequence_binary_operator	bool
IDS_Trinary_Operator	is_ideograph_description_sequence_trinary_operator	bool
Indic_Positional_Category	indic_positional_category	Option<IndicPositionalCategory>
Indic_Syllabic_Category	indic_syllabic_category	Option<IndicSyllabicCategory>
Jamo_Short_Name	jamo_short_name	Option<&str>
Join_Control	join_control	bool
Joining_Group	joining_group	JoiningGroup
Joining_Type	joining_type	JoiningType
Radical	is_ideograph_description_sequence_radical	bool
Script	script	Option<Script>
Script_Extensions	script_extensions	Option<&[Script]>
Unified_Ideograph	is_ideograph_unified	bool

Bidirectionality	Method	Return Type	Note
Bidi_Class	bidi_class	BidiClass
Bidi_Control	bidi_is_control	bool
Bidi_Mirrored	bidi_is_mirrored	bool
Bidi_Mirroring_Glyph	bidi_mirror	Option<char>
Bidi_Paired_Bracket	bidi_paired_braclet	char
Bidi_Paired_Bracket_Type	bidi_paired_bracket_type	Option<BidiPairedBracketType>

Case	Method	Return Type	Note
Case_Folding	casefold	CharIter	CharIter is an iterator over a series of chars, and is used because the library makes no use of std and thus cannot dynamically allocate memory.
Case_Ignorable	is_case_ignorable	bool
Cased	is_cased	bool
Changes_When_Casefolded	changes_when_casefolded	bool
Changes_When_Casemapped	changes_when_casemapped	bool
Changes_When_Lowercased	changes_when_lowercased	bool
Changes_When_NFKC_Casefolded	changes_when_casefolded_nfkc	bool
Changes_When_Titlecased	changes_when_titlecased	bool
Changes_When_Uppercased	changes_when_uppercased	bool
FC_NFKC_Closure (deprecated)	casefold_nfkc_closure	CharIter
Lowercase	is_lowercase	bool	Again, char shadows this with its own implementation so use the namespace or alias.
Lowercase_Mapping	lowercase	CharIter
NFKC_Casefold	casefold_nfkc	CharIter
Other_Lowercase	is_lowercase_other	bool
Other_Uppercase	is_uppercase_other	bool
Simple_Case_Folding	casefold_simple	char
Simple_Lowercase_Mapping	lowercase_simple	char
Simple_Titlecase_Mapping	titlecase_simple	char
Simple_Uppercase_Mapping	uppercase_simple	char
Titlecase_Mapping	titlecase	CharIter
Uppercase	is_uppercase	bool	Again, char shadows this with its own implementation so use the namespace or alias.
Uppercase_Mapping	uppercase	CharIter

Normalisation	Method	Return Type	Note
Canonical_Combining_Class	canonical_combining_class	u8
Composition_Exclusion	excluded_from_composition	bool
Decomposition_Mapping	decomposition_map	CharIter
Decomposition_Type	decomposition_type	Option<DecompositionType>
Expands_On_NFC (deprecated)	expands_on_nfc	bool
Expands_On_NFD (deprecated)	expands_on_nfd	bool
Expands_On_NFKC (deprecated)	expands_on_nfkc	bool
Expands_On_NFKD (deprecated)	expands_on_nfkd	bool
Full_Composition_Exclusion	excluded_from_composition_fully	bool
NFC_Quick_Check	quick_check_nfc	Trilean	Returns one of Trilean::True, Trilean::Maybe or Trilean::False
NFD_Quick_Check	quick_check_nfd	bool
NFKC_Quick_Check	quick_check_nfkc	Trilean
NFKD_Quick_Check	quick_check_nfkd	bool

Segmentation	Method	Return Type	Note
Grapheme_Base	is_grapheme_base	bool
Grapheme_Cluster_Break	grapheme_cluster_break	GraphemeClusterBreak
Grapheme_Extend	is_grapheme_extend	bool
Grapheme_Link (deprecated)	is_grapheme_link	bool
Line_Break	linebreak_class	Option<LinebreakClass>
Other_Grapheme_Extend	is_grapheme_extend_other	bool
Sentence_Break	sentence_break	SentenceBreak
Word_Break	word_break	WordBreak