Wide_String Handling
Author: JTC1/SC22/WG9/ARG, by Randall Brukardt, ARG Editor

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# A.4.7 Wide_String Handling

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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 functions Strings.Wide_Hash, Strings.Wide_Fixed.Wide_Hash, Strings.Wide_Bounded.Wide_Hash, and Strings.Wide_Unbounded.Wide_Hash. They provide the same string-handling operations as the corresponding packages and functions for strings of Character elements.

#### Static Semantics

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The package Strings.Wide_Maps has the following declaration.
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package Ada.Strings.Wide_Maps is
pragma Preelaborate(Wide_Maps);
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-- Representation for a set of Wide_Character values:
type Wide_Character_Set is private;
pragma Preelaborable_Initialization(Wide_Character_Set);
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Null_Set : constant Wide_Character_Set;
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type Wide_Character_Range is
record
Low : Wide_Character;
High : Wide_Character;
end record;
-- Represents Wide_Character range Low..High
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type Wide_Character_Ranges is array (Positive range <>)
of Wide_Character_Range;
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function To_Set (Ranges : in Wide_Character_Ranges)
return Wide_Character_Set;
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function To_Set (Span : in Wide_Character_Range)
return Wide_Character_Set;
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function To_Ranges (Set : in Wide_Character_Set)
return Wide_Character_Ranges;
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function "=" (Left, Right : in Wide_Character_Set) return Boolean;
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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;
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function Is_In (Element : in Wide_Character;
Set : in Wide_Character_Set)
return Boolean;
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function Is_Subset (Elements : in Wide_Character_Set;
Set : in Wide_Character_Set)
return Boolean;
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function "<=" (Left : in Wide_Character_Set;
Right : in Wide_Character_Set)
return Boolean renames Is_Subset;
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-- Alternative representation for a set of Wide_Character values:
subtype Wide_Character_Sequence is Wide_String;
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function To_Set (Sequence : in Wide_Character_Sequence)
return Wide_Character_Set;
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function To_Set (Singleton : in Wide_Character)
return Wide_Character_Set;
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function To_Sequence (Set : in Wide_Character_Set)
return Wide_Character_Sequence;
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-- Representation for a Wide_Character to Wide_Character mapping:
type Wide_Character_Mapping is private;
pragma Preelaborable_Initialization(Wide_Character_Mapping);
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function Value (Map : in Wide_Character_Mapping;
Element : in Wide_Character)
return Wide_Character;
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Identity : constant Wide_Character_Mapping;
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function To_Mapping (From, To : in Wide_Character_Sequence)
return Wide_Character_Mapping;
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function To_Domain (Map : in Wide_Character_Mapping)
return Wide_Character_Sequence;
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function To_Range (Map : in Wide_Character_Mapping)
return Wide_Character_Sequence;
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type Wide_Character_Mapping_Function is
access function (From : in Wide_Character) return Wide_Character;
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private
... -- not specified by the language
end Ada.Strings.Wide_Maps;
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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.
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For each of the packages Strings.Fixed, Strings.Bounded, Strings.Unbounded, and Strings.Maps.Constants, and for functions Strings.Hash, Strings.Fixed.Hash, Strings.Bounded.Hash, and Strings.Unbounded.Hash, the corresponding wide string package has the same contents except that
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- Wide_Space replaces Space

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- Wide_Character replaces Character

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- Wide_String replaces String

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- Wide_Character_Set replaces Character_Set

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- Wide_Character_Mapping replaces Character_Mapping

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- Wide_Character_Mapping_Function replaces Character_Mapping_Function

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- Wide_Maps replaces Maps

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- Bounded_Wide_String replaces Bounded_String

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- Null_Bounded_Wide_String replaces Null_Bounded_String

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- To_Bounded_Wide_String replaces To_Bounded_String

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- To_Wide_String replaces To_String

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- Set_Bounded_Wide_String replaces Set_Bounded_String

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- Unbounded_Wide_String replaces Unbounded_String

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- Null_Unbounded_Wide_String replaces Null_Unbounded_String

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- Wide_String_Access replaces String_Access

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- To_Unbounded_Wide_String replaces To_Unbounded_String

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- Set_Unbounded_Wide_String replaces Set_Unbounded_String

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The following additional declaration is present in Strings.Wide_Maps.Wide_Constants:
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Character_Set : constant Wide_Maps.Wide_Character_Set;
--Contains each Wide_Character value WC such that
--Characters.Conversions.Is_Character(WC) is True
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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.
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Pragma Pure is replaced by pragma Preelaborate in Strings.Wide_Maps.Wide_Constants.
NOTES
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12 If a null Wide_Character_Mapping_Function is passed to any of the Wide_String handling subprograms, Constraint_Error is propagated.
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This paragraph was deleted.

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