Files
VSS/source/text/implementation/vss-implementation-utf8_encoding.ads
2022-06-21 10:14:14 +03:00

69 lines
2.1 KiB
Ada

--
-- Copyright (C) 2020-2021, AdaCore
--
-- SPDX-License-Identifier: Apache-2.0
--
-- Utilities to encode/decode UTF-8 encoded data.
with Ada.Streams;
with VSS.Stream_Element_Vectors;
with VSS.Unicode;
package VSS.Implementation.UTF8_Encoding is
pragma Preelaborate;
type UTF8_Code_Unit_Array is
array (VSS.Unicode.UTF8_Code_Unit_Count range <>)
of VSS.Unicode.UTF8_Code_Unit;
subtype UTF8_Sequence_Length
is VSS.Unicode.UTF8_Code_Unit_Count range 1 .. 4;
pragma Warnings (Off, "aspect ""PRE"" not enforced on inlined subprogram");
procedure Encode
(Code : VSS.Unicode.Code_Point;
Length : out UTF8_Sequence_Length;
Unit_1 : out VSS.Unicode.UTF8_Code_Unit;
Unit_2 : out VSS.Unicode.UTF8_Code_Unit;
Unit_3 : out VSS.Unicode.UTF8_Code_Unit;
Unit_4 : out VSS.Unicode.UTF8_Code_Unit)
with Inline_Always, Pre => Code not in 16#D800# .. 16#DFFF#;
pragma Warnings (On, "aspect ""PRE"" not enforced on inlined subprogram");
-- Encode code point. Size is actual number of code units, U1 .. U4 values
-- of code units.
type UTF8_Decode_Error is
(None,
Incomplete_2,
Incomplete_3,
Incomplete_4,
Invalid_1,
Invalid_2_Of_2,
Invalid_2_Of_3,
Invalid_3_Of_3,
Invalid_2_Of_4,
Invalid_3_Of_4,
Invalid_4_Of_4);
procedure Decode
(Data : VSS.Stream_Element_Vectors.Stream_Element_Vector;
Index : in out Ada.Streams.Stream_Element_Count;
Code : out VSS.Unicode.Code_Point;
Success : in out Boolean;
Error : out UTF8_Decode_Error);
procedure Unchecked_Store
(Storage : in out VSS.Implementation.UTF8_Encoding.UTF8_Code_Unit_Array;
From : VSS.Unicode.UTF8_Code_Unit_Offset;
Length : VSS.Implementation.UTF8_Encoding.UTF8_Sequence_Length;
Unit_1 : VSS.Unicode.UTF8_Code_Unit;
Unit_2 : VSS.Unicode.UTF8_Code_Unit;
Unit_3 : VSS.Unicode.UTF8_Code_Unit;
Unit_4 : VSS.Unicode.UTF8_Code_Unit) with Inline_Always;
-- Store encoded character.
end VSS.Implementation.UTF8_Encoding;