Ada 2012 Reference Manual

A.4.7 Wide_String Handling

Facilities for handling strings of Wide_Character elements are found in the packages Strings.Wide_Maps, Strings.Wide_Fixed, Strings.Wide_Bounded, Strings.Wide_Unbounded, and Strings.Wide_Maps.Wide_Constants, and in the library functions Strings.Wide_Hash, Strings.Wide_Fixed.Wide_Hash, Strings.Wide_Bounded.Wide_Hash, Strings.Wide_Unbounded.Wide_Hash, Strings.Wide_Hash_Case_Insensitive, Strings.Wide_Fixed.Wide_Hash_Case_Insensitive, Strings.Wide_Bounded.Wide_Hash_Case_Insensitive, Strings.Wide_Unbounded.Wide_Hash_Case_Insensitive, Strings.Wide_Equal_Case_Insensitive, Strings.Wide_Fixed.Wide_Equal_Case_Insensitive, Strings.Wide_Bounded.Wide_Equal_Case_Insensitive, and Strings.Wide_Unbounded.Wide_Equal_Case_Insensitive. They provide the same string-handling operations as the corresponding packages and functions for strings of Character elements.

Static Semantics

The package Strings.Wide_Maps has the following declaration.

package Ada.Strings.Wide_Maps is
pragma Preelaborate(Wide_Maps);

-- Representation for a set of Wide_Character values:
type Wide_Character_Set is private;
pragma Preelaborable_Initialization(Wide_Character_Set);

Null_Set : constant Wide_Character_Set;

type Wide_Character_Range is
record
Low : Wide_Character;
High : Wide_Character;
end record;
-- Represents Wide_Character range Low..High

type Wide_Character_Ranges is array (Positive range <>)
of Wide_Character_Range;

function To_Set (Ranges : in Wide_Character_Ranges)
return Wide_Character_Set;

function To_Set (Span : in Wide_Character_Range)
return Wide_Character_Set;

function To_Ranges (Set : in Wide_Character_Set)
return Wide_Character_Ranges;

function "=" (Left, Right : in Wide_Character_Set) return Boolean;

function "not" (Right : in Wide_Character_Set)
return Wide_Character_Set;
function "and" (Left, Right : in Wide_Character_Set)
return Wide_Character_Set;
function "or" (Left, Right : in Wide_Character_Set)
return Wide_Character_Set;
function "xor" (Left, Right : in Wide_Character_Set)
return Wide_Character_Set;
function "-" (Left, Right : in Wide_Character_Set)
return Wide_Character_Set;

function Is_In (Element : in Wide_Character;
Set : in Wide_Character_Set)
return Boolean;

function Is_Subset (Elements : in Wide_Character_Set;
Set : in Wide_Character_Set)
return Boolean;

function "<=" (Left : in Wide_Character_Set;
Right : in Wide_Character_Set)
return Boolean renames Is_Subset;

-- Alternative representation for a set of Wide_Character values:
subtype Wide_Character_Sequence is Wide_String;

function To_Set (Sequence : in Wide_Character_Sequence)
return Wide_Character_Set;

function To_Set (Singleton : in Wide_Character)
return Wide_Character_Set;

function To_Sequence (Set : in Wide_Character_Set)
return Wide_Character_Sequence;

-- Representation for a Wide_Character to Wide_Character mapping:
type Wide_Character_Mapping is private;
pragma Preelaborable_Initialization(Wide_Character_Mapping);

function Value (Map : in Wide_Character_Mapping;
Element : in Wide_Character)
return Wide_Character;

Identity : constant Wide_Character_Mapping;

function To_Mapping (From, To : in Wide_Character_Sequence)
return Wide_Character_Mapping;

function To_Domain (Map : in Wide_Character_Mapping)
return Wide_Character_Sequence;

function To_Range (Map : in Wide_Character_Mapping)
return Wide_Character_Sequence;

type Wide_Character_Mapping_Function is
access function (From : in Wide_Character) return Wide_Character;

private
... -- not specified by the language
end Ada.Strings.Wide_Maps;

The context clause for each of the packages Strings.Wide_Fixed, Strings.Wide_Bounded, and Strings.Wide_Unbounded identifies Strings.Wide_Maps instead of Strings.Maps.

Types Wide_Character_Set and Wide_Character_Mapping need finalization.

For each of the packages Strings.Fixed, Strings.Bounded, Strings.Unbounded, and Strings.Maps.Constants, and for library functions Strings.Hash, Strings.Fixed.Hash, Strings.Bounded.Hash, Strings.Unbounded.Hash, Strings.Hash_Case_Insensitive, Strings.Fixed.Hash_Case_Insensitive, Strings.Bounded.Hash_Case_Insensitive, Strings.Unbounded.Hash_Case_Insensitive, Strings.Equal_Case_Insensitive, Strings.Fixed.Equal_Case_Insensitive, Strings.Bounded.Equal_Case_Insensitive, and Strings.Unbounded.Equal_Case_Insensitive, the corresponding wide string package or function has the same contents except that

Wide_Space replaces Space

Wide_Character replaces Character

Wide_String replaces String

Wide_Character_Set replaces Character_Set

Wide_Character_Mapping replaces Character_Mapping

Wide_Character_Mapping_Function replaces Character_Mapping_Function

Wide_Maps replaces Maps

Bounded_Wide_String replaces Bounded_String

Null_Bounded_Wide_String replaces Null_Bounded_String

To_Bounded_Wide_String replaces To_Bounded_String

To_Wide_String replaces To_String

Set_Bounded_Wide_String replaces Set_Bounded_String

Unbounded_Wide_String replaces Unbounded_String

Null_Unbounded_Wide_String replaces Null_Unbounded_String

Wide_String_Access replaces String_Access

To_Unbounded_Wide_String replaces To_Unbounded_String

Set_Unbounded_Wide_String replaces Set_Unbounded_String

The following additional declaration is present in Strings.Wide_Maps.Wide_Constants:

Character_Set : constant Wide_Maps.Wide_Character_Set;
--Contains each Wide_Character value WC such that
--Characters.Conversions.Is_Character(WC) is True

Each Wide_Character_Set constant in the package Strings.Wide_Maps.Wide_Constants contains no values outside the Character portion of Wide_Character. Similarly, each Wide_Character_Mapping constant in this package is the identity mapping when applied to any element outside the Character portion of Wide_Character.

Pragma Pure is replaced by pragma Preelaborate in Strings.Wide_Maps.Wide_Constants.

NOTES

16 If a null Wide_Character_Mapping_Function is passed to any of the Wide_String handling subprograms, Constraint_Error is propagated.