Ada Reference Manual (Ada 2022)
A.3.5 The Package Wide_Characters.Handling
The package Wide_Characters.Handling provides operations for classifying Wide_Characters and case folding for Wide_Characters.
Static Semantics
The library package Wide_Characters.Handling has the following declaration:
package Ada.Wide_Characters.Handling
with Pure is
with Pure is
function Character_Set_Version return String;
function Is_Control (Item : Wide_Character) return Boolean;
function Is_Letter (Item : Wide_Character) return Boolean;
function Is_Lower (Item : Wide_Character) return Boolean;
function Is_Upper (Item : Wide_Character) return Boolean;
function Is_Basic (Item : Wide_Character) return Boolean;
function Is_Digit (Item : Wide_Character) return Boolean;
function Is_Decimal_Digit (Item : Wide_Character) return Boolean
renames Is_Digit;
renames Is_Digit;
function Is_Hexadecimal_Digit (Item : Wide_Character) return Boolean;
function Is_Alphanumeric (Item : Wide_Character) return Boolean;
function Is_Special (Item : Wide_Character) return Boolean;
function Is_Line_Terminator (Item : Wide_Character) return Boolean;
function Is_Mark (Item : Wide_Character) return Boolean;
function Is_Other_Format (Item : Wide_Character) return Boolean;
function Is_Punctuation_Connector (Item : Wide_Character) return Boolean;
function Is_Space (Item : Wide_Character) return Boolean;
function Is_NFKC (Item : Wide_Character) return Boolean;
function Is_Graphic (Item : Wide_Character) return Boolean;
function To_Lower (Item : Wide_Character) return Wide_Character;
function To_Upper (Item : Wide_Character) return Wide_Character;
function To_Upper (Item : Wide_Character) return Wide_Character;
function To_Basic (Item : Wide_Character) return Wide_Character;
function To_Lower (Item : Wide_String) return Wide_String;
function To_Upper (Item : Wide_String) return Wide_String;
function To_Upper (Item : Wide_String) return Wide_String;
function To_Basic (Item : Wide_String) return Wide_String;
end Ada.Wide_Characters.Handling;
The subprograms defined in Wide_Characters.Handling are locale independent.
function Character_Set_Version return String;
Returns an implementation-defined identifier that identifies the version of the character set standard that is used for categorizing characters by the implementation.
function Is_Control (Item : Wide_Character) return Boolean;
Returns True if the Wide_Character designated by Item is categorized as other_control; otherwise returns False.
function Is_Letter (Item : Wide_Character) return Boolean;
Returns True if the Wide_Character designated by Item is categorized as letter_uppercase, letter_lowercase, letter_titlecase, letter_modifier, letter_other, or number_letter; otherwise returns False.
function Is_Lower (Item : Wide_Character) return Boolean;
Returns True if the Wide_Character designated by Item is categorized as letter_lowercase; otherwise returns False.
function Is_Upper (Item : Wide_Character) return Boolean;
Returns True if the Wide_Character designated by Item is categorized as letter_uppercase; otherwise returns False.
function Is_Basic (Item : Wide_Character) return Boolean;
Returns True if the Wide_Character designated by Item has no Decomposition Mapping in the code charts of ISO/IEC 10646:2020; otherwise returns False.
function Is_Digit (Item : Wide_Character) return Boolean;
Returns True if the Wide_Character designated by Item is categorized as number_decimal; otherwise returns False.
function Is_Hexadecimal_Digit (Item : Wide_Character) return Boolean;
Returns True if the Wide_Character designated by Item is categorized as number_decimal, or is in the range 'A' .. 'F' or 'a' .. 'f'; otherwise returns False.
function Is_Alphanumeric (Item : Wide_Character) return Boolean;
Returns True if the Wide_Character designated by Item is categorized as letter_uppercase, letter_lowercase, letter_titlecase, letter_modifier, letter_other, number_letter, or number_decimal; otherwise returns False.
function Is_Special (Item : Wide_Character) return Boolean;
Returns True if the Wide_Character designated by Item is categorized as graphic_character, but not categorized as letter_uppercase, letter_lowercase, letter_titlecase, letter_modifier, letter_other, number_letter, or number_decimal; otherwise returns False.
function Is_Line_Terminator (Item : Wide_Character) return Boolean;
Returns True if the Wide_Character designated by Item is categorized as separator_line or separator_paragraph, or if Item is a conventional line terminator character (Line_Feed, Line_Tabulation, Form_Feed, Carriage_Return, Next_Line); otherwise returns False.
function Is_Mark (Item : Wide_Character) return Boolean;
Returns True if the Wide_Character designated by Item is categorized as mark_non_spacing or mark_spacing_combining; otherwise returns False.
function Is_Other_Format (Item : Wide_Character) return Boolean;
Returns True if the Wide_Character designated by Item is categorized as other_format; otherwise returns False.
function Is_Punctuation_Connector (Item : Wide_Character) return Boolean;
Returns True if the Wide_Character designated by Item is categorized as punctuation_connector; otherwise returns False.
function Is_Space (Item : Wide_Character) return Boolean;
Returns True if the Wide_Character designated by Item is categorized as separator_space; otherwise returns False.
function Is_NFKC (Item : Wide_Character) return Boolean;
Returns True if the Wide_Character designated by Item can be present in a string normalized to Normalization Form KC (as defined by Clause 22 of ISO/IEC 10646:2020), otherwise returns False.
function Is_Graphic (Item : Wide_Character) return Boolean;
Returns True if the Wide_Character designated by Item is categorized as graphic_character; otherwise returns False.
function To_Lower (Item : Wide_Character) return Wide_Character;
Returns the Simple Lowercase Mapping as defined by documents referenced in Clause 2 of ISO/IEC 10646:2020 of the Wide_Character designated by Item. If the Simple Lowercase Mapping does not exist for the Wide_Character designated by Item, then the value of Item is returned.
function To_Lower (Item : Wide_String) return Wide_String;
Returns the result of applying the To_Lower conversion to each Wide_Character element of the Wide_String designated by Item. The result is the null Wide_String if the value of the formal parameter is the null Wide_String. The lower bound of the result Wide_String is 1.
function To_Upper (Item : Wide_Character) return Wide_Character;
Returns the Simple Uppercase Mapping as defined by documents referenced in Clause 2 of ISO/IEC 10646:2020 of the Wide_Character designated by Item. If the Simple Uppercase Mapping does not exist for the Wide_Character designated by Item, then the value of Item is returned.
function To_Upper (Item : Wide_String) return Wide_String;
Returns the result of applying the To_Upper conversion to each Wide_Character element of the Wide_String designated by Item. The result is the null Wide_String if the value of the formal parameter is the null Wide_String. The lower bound of the result Wide_String is 1.
function To_Basic (Item : Wide_Character) return Wide_Character;
Returns the Wide_Character whose code point is given by the first value of its Decomposition Mapping in the code charts of ISO/IEC 10646:2020 if any; returns Item otherwise.
function To_Basic (Item : Wide_String) return Wide_String;
Returns the result of applying the To_Basic conversion to each Wide_Character element of the Wide_String designated by Item. The result is the null Wide_String if the value of the formal parameter is the null Wide_String. The lower bound of the result Wide_String is 1.
Implementation Advice
The string returned by Character_Set_Version should include either “10646:” or “Unicode”.
NOTE 1 The results returned by these functions can depend on which particular version of ISO/IEC 10646 is supported by the implementation (see 2.1).
NOTE 2 The case insensitive equality comparison routines provided in A.4.10 are also available for wide strings (see A.4.7).
