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|
------------------------------------------------------------------------------
-- --
-- GNAT RUN-TIME COMPONENTS --
-- --
-- A D A . C H A R A C T E R S . H A N D L I N G --
-- --
-- S p e c --
-- --
-- Copyright (C) 1992-2022, Free Software Foundation, Inc. --
-- --
-- This specification is derived from the Ada Reference Manual for use with --
-- GNAT. The copyright notice above, and the license provisions that follow --
-- apply solely to the contents of the part following the private keyword. --
-- --
-- GNAT is free software; you can redistribute it and/or modify it under --
-- terms of the GNU General Public License as published by the Free Soft- --
-- ware Foundation; either version 3, or (at your option) any later ver- --
-- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
-- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
-- or FITNESS FOR A PARTICULAR PURPOSE. --
-- --
-- As a special exception under Section 7 of GPL version 3, you are granted --
-- additional permissions described in the GCC Runtime Library Exception, --
-- version 3.1, as published by the Free Software Foundation. --
-- --
-- You should have received a copy of the GNU General Public License and --
-- a copy of the GCC Runtime Library Exception along with this program; --
-- see the files COPYING3 and COPYING.RUNTIME respectively. If not, see --
-- <http://www.gnu.org/licenses/>. --
-- --
-- GNAT was originally developed by the GNAT team at New York University. --
-- Extensive contributions were provided by Ada Core Technologies Inc. --
-- --
------------------------------------------------------------------------------
-- Postconditions in this unit are meant for analysis only, not for run-time
-- checking, in order not to slow down the execution of these functions.
pragma Assertion_Policy (Post => Ignore);
with Ada.Characters.Latin_1;
package Ada.Characters.Handling
with SPARK_Mode
is
pragma Pure;
-- In accordance with Ada 2005 AI-362
----------------------------------------
-- Character Classification Functions --
----------------------------------------
-- In the description below for each function that returns a Boolean
-- result, the effect is described in terms of the conditions under which
-- the value True is returned. If these conditions are not met, then the
-- function returns False.
--
-- Each of the following classification functions has a formal Character
-- parameter, Item, and returns a Boolean result.
function Is_Control (Item : Character) return Boolean
with
Post => Is_Control'Result =
(Character'Pos (Item) in 0 .. 31 | 127 .. 159);
-- True if Item is a control character. A control character is a character
-- whose position is in one of the ranges 0..31 or 127..159.
function Is_Graphic (Item : Character) return Boolean
with
Post => Is_Graphic'Result =
(Character'Pos (Item) in 32 .. 126 | 160 .. 255);
-- True if Item is a graphic character. A graphic character is a character
-- whose position is in one of the ranges 32..126 or 160..255.
function Is_Letter (Item : Character) return Boolean
with
Post => Is_Letter'Result =
(Item in 'A' .. 'Z' | 'a' .. 'z'
or else Character'Pos (Item) in 192 .. 214 | 216 .. 246 | 248 .. 255);
-- True if Item is a letter. A letter is a character that is in one of the
-- ranges 'A'..'Z' or 'a'..'z', or whose position is in one of the ranges
-- 192..214, 216..246, or 248..255.
function Is_Lower (Item : Character) return Boolean
with
Post => Is_Lower'Result =
(Item in 'a' .. 'z'
or else Character'Pos (Item) in 223 .. 246 | 248 .. 255);
-- True if Item is a lower-case letter. A lower-case letter is a character
-- that is in the range 'a'..'z', or whose position is in one of the ranges
-- 223..246 or 248..255.
function Is_Upper (Item : Character) return Boolean
with
Post => Is_Upper'Result =
(Item in 'A' .. 'Z'
or else Character'Pos (Item) in 192 .. 214 | 216 .. 222);
-- True if Item is an upper-case letter. An upper-case letter is a
-- character that is in the range 'A'..'Z' or whose position is in one
-- of the ranges 192..214 or 216..222.
function Is_Basic (Item : Character) return Boolean
with
Post => Is_Basic'Result =
(Item in 'A' .. 'Z'
| 'a' .. 'z'
| Latin_1.UC_AE_Diphthong
| Latin_1.LC_AE_Diphthong
| Latin_1.UC_Icelandic_Eth
| Latin_1.LC_Icelandic_Eth
| Latin_1.UC_Icelandic_Thorn
| Latin_1.LC_Icelandic_Thorn
| Latin_1.LC_German_Sharp_S);
-- True if Item is a basic letter. A basic letter is a character that
-- is in one of the ranges 'A'..'Z' and 'a'..'z', or that is one of
-- the following: UC_AE_Diphthong, LC_AE_Diphthong, UC_Icelandic_Eth,
-- LC_Icelandic_Eth, UC_Icelandic_Thorn, LC_Icelandic_Thorn, or
-- LC_German_Sharp_S.
function Is_Digit (Item : Character) return Boolean
with
Post => Is_Digit'Result = (Item in '0' .. '9');
-- True if Item is a decimal digit. A decimal digit is a character in the
-- range '0'..'9'.
function Is_Decimal_Digit (Item : Character) return Boolean
renames Is_Digit;
function Is_Hexadecimal_Digit (Item : Character) return Boolean
with
Post => Is_Hexadecimal_Digit'Result =
(Is_Decimal_Digit (Item) or Item in 'A' .. 'F' | 'a' .. 'f');
-- True if Item is a hexadecimal digit. A hexadecimal digit is a character
-- that is either a decimal digit or that is in one of the ranges 'A'..'F'
-- or 'a'..'f'.
function Is_Alphanumeric (Item : Character) return Boolean
with
Post => Is_Alphanumeric'Result =
(Is_Letter (Item) or Is_Decimal_Digit (Item));
-- True if Item is an alphanumeric character. An alphanumeric character is
-- a character that is either a letter or a decimal digit.
function Is_Special (Item : Character) return Boolean
with
Post => Is_Special'Result =
(Is_Graphic (Item) and not Is_Alphanumeric (Item));
-- True if Item is a special graphic character. A special graphic character
-- is a graphic character that is not alphanumeric.
function Is_Line_Terminator (Item : Character) return Boolean
with
Post => Is_Line_Terminator'Result =
(Character'Pos (Item) in 10 .. 13 | 133);
-- True if Item is a character with position 10..13 (Line_Feed,
-- Line_Tabulation, Form_Feed, Carriage_Return) or 133 (Next_Line).
function Is_Mark (Item : Character) return Boolean
with
Post => Is_Mark'Result = False;
-- Never True (no value of type Character has categories Mark, Non-Spacing
-- or Mark, Spacing Combining).
function Is_Other_Format (Item : Character) return Boolean
with
Post => Is_Other_Format'Result = (Character'Pos (Item) = 173);
-- True if Item is a character with position 173 (Soft_Hyphen).
function Is_Punctuation_Connector (Item : Character) return Boolean
with
Post => Is_Punctuation_Connector'Result =
(Character'Pos (Item) = 95);
-- True if Item is a character with position 95 ('_', known as Low_Line or
-- Underscore).
function Is_Space (Item : Character) return Boolean
with
Post => Is_Space'Result = (Character'Pos (Item) in 32 | 160);
-- True if Item is a character with position 32 (' ') or 160
-- (No_Break_Space).
function Is_NFKC (Item : Character) return Boolean
with
Post => Is_NFKC'Result =
(Character'Pos (Item) not in
160 | 168 | 170 | 175 | 178 | 179 | 180
| 181 | 184 | 185 | 186 | 188 | 189 | 190);
-- True if Item could be present in a string normalized to Normalization
-- Form KC (as defined by Clause 21 of ISO/IEC 10646:2017); this includes
-- all characters except those with positions 160, 168, 170, 175, 178, 179,
-- 180, 181, 184, 185, 186, 188, 189, and 190.
---------------------------------------------------
-- Conversion Functions for Character and String --
---------------------------------------------------
-- Each of the names To_Lower, To_Upper, and To_Basic refers to two
-- functions: one that converts from Character to Character, and
-- the other that converts from String to String. The result of each
-- Character-to-Character function is described below, in terms of
-- the conversion applied to Item, its formal Character parameter. The
-- result of each String-to-String conversion is obtained by applying
-- to each element of the function's String parameter the corresponding
-- Character-to-Character conversion; the result is the null String if the
-- value of the formal parameter is the null String. The lower bound of the
-- result String is 1.
function To_Lower (Item : Character) return Character
with
Post => To_Lower'Result =
(if Is_Upper (Item) then
Character'Val (Character'Pos (Item) +
(if Item in 'A' .. 'Z' then
Character'Pos ('a') - Character'Pos ('A')
else
Character'Pos (Latin_1.LC_A_Grave)
- Character'Pos (Latin_1.UC_A_Grave)))
else
Item);
-- Returns the corresponding lower-case value for Item if Is_Upper(Item),
-- and returns Item otherwise.
function To_Upper (Item : Character) return Character
with
Post => To_Upper'Result =
(if Is_Lower (Item)
and then Item not in Latin_1.LC_German_Sharp_S
| Latin_1.LC_Y_Diaeresis
then
Character'Val (Character'Pos (Item) +
(if Item in 'A' .. 'Z' then
Character'Pos ('A') - Character'Pos ('a')
else
Character'Pos (Latin_1.UC_A_Grave)
- Character'Pos (Latin_1.LC_A_Grave)))
else
Item);
-- Returns the corresponding upper-case value for Item if Is_Lower(Item)
-- and Item has an upper-case form, and returns Item otherwise. The lower
-- case letters LC_German_Sharp_S and LC_Y_Diaeresis do not have upper case
-- forms.
function To_Basic (Item : Character) return Character
with
Post => To_Basic'Result =
(if not Is_Letter (Item) or else Is_Basic (Item) then
Item
else
(case Item is
when Latin_1.UC_A_Grave .. Latin_1.UC_A_Ring => 'A',
when Latin_1.UC_C_Cedilla => 'C',
when Latin_1.UC_E_Grave .. Latin_1.UC_E_Diaeresis => 'E',
when Latin_1.UC_I_Grave .. Latin_1.UC_I_Diaeresis => 'I',
when Latin_1.UC_N_Tilde => 'N',
when Latin_1.UC_O_Grave .. Latin_1.UC_O_Diaeresis => 'O',
when Latin_1.UC_O_Oblique_Stroke => 'O',
when Latin_1.UC_U_Grave .. Latin_1.UC_U_Diaeresis => 'U',
when Latin_1.UC_Y_Acute => 'Y',
when Latin_1.LC_A_Grave .. Latin_1.LC_A_Ring => 'a',
when Latin_1.LC_C_Cedilla => 'c',
when Latin_1.LC_E_Grave .. Latin_1.LC_E_Diaeresis => 'e',
when Latin_1.LC_I_Grave .. Latin_1.LC_I_Diaeresis => 'i',
when Latin_1.LC_N_Tilde => 'n',
when Latin_1.LC_O_Grave .. Latin_1.LC_O_Diaeresis => 'o',
when Latin_1.LC_O_Oblique_Stroke => 'o',
when Latin_1.LC_U_Grave .. Latin_1.LC_U_Diaeresis => 'u',
when Latin_1.LC_Y_Acute => 'y',
when Latin_1.LC_Y_Diaeresis => 'y',
when others => raise Program_Error));
-- Returns the letter corresponding to Item but with no diacritical mark,
-- if Item is a letter but not a basic letter; returns Item otherwise.
function To_Lower (Item : String) return String
with
Post => To_Lower'Result'First = 1
and then To_Lower'Result'Length = Item'Length
and then
(for all J in To_Lower'Result'Range =>
To_Lower'Result (J) = To_Lower (Item (Item'First + (J - 1))));
function To_Upper (Item : String) return String
with
Post => To_Upper'Result'First = 1
and then To_Upper'Result'Length = Item'Length
and then
(for all J in To_Upper'Result'Range =>
To_Upper'Result (J) = To_Upper (Item (Item'First + (J - 1))));
function To_Basic (Item : String) return String
with
Post => To_Basic'Result'First = 1
and then To_Basic'Result'Length = Item'Length
and then
(for all J in To_Basic'Result'Range =>
To_Basic'Result (J) = To_Basic (Item (Item'First + (J - 1))));
----------------------------------------------------------------------
-- Classifications of and Conversions Between Character and ISO 646 --
----------------------------------------------------------------------
-- The following set of functions test for membership in the ISO 646
-- character range, or convert between ISO 646 and Character.
subtype ISO_646 is
Character range Character'Val (0) .. Character'Val (127);
function Is_ISO_646 (Item : Character) return Boolean
with
Post => Is_ISO_646'Result = (Item in ISO_646);
-- The function whose formal parameter, Item, is of type Character returns
-- True if Item is in the subtype ISO_646.
function Is_ISO_646 (Item : String) return Boolean
with
Post => Is_ISO_646'Result =
(for all J in Item'Range => Is_ISO_646 (Item (J)));
-- The function whose formal parameter, Item, is of type String returns
-- True if Is_ISO_646(Item(I)) is True for each I in Item'Range.
function To_ISO_646
(Item : Character;
Substitute : ISO_646 := ' ') return ISO_646
with
Post => To_ISO_646'Result =
(if Is_ISO_646 (Item) then Item else Substitute);
-- The function whose first formal parameter, Item, is of type Character
-- returns Item if Is_ISO_646(Item), and returns the Substitute ISO_646
-- character otherwise.
function To_ISO_646
(Item : String;
Substitute : ISO_646 := ' ') return String
with
Post => To_ISO_646'Result'First = 1
and then To_ISO_646'Result'Length = Item'Length
and then
(for all J in To_ISO_646'Result'Range =>
To_ISO_646'Result (J) =
To_ISO_646 (Item (Item'First + (J - 1)), Substitute));
-- The function whose first formal parameter, Item, is of type String
-- returns the String whose Range is 1..Item'Length and each of whose
-- elements is given by To_ISO_646 of the corresponding element in Item.
------------------------------------------------------
-- Classifications of Wide_Character and Characters --
------------------------------------------------------
-- Ada 2005 AI 395: these functions are moved to Ada.Characters.Conversions
-- and are considered obsolete in Ada.Characters.Handling. However we do
-- not complain about this obsolescence, since in practice it is necessary
-- to use these routines when creating code that is intended to run in
-- either Ada 95 or Ada 2005 mode.
-- We do however have to flag these if the pragma No_Obsolescent_Features
-- restriction is active (see Restrict.Check_Obsolescent_2005_Entity).
function Is_Character (Item : Wide_Character) return Boolean
with
Post => Is_Character'Result =
(Wide_Character'Pos (Item) <= Character'Pos (Character'Last));
-- Returns True if Wide_Character'Pos(Item) <=
-- Character'Pos(Character'Last).
function Is_String (Item : Wide_String) return Boolean
with
Post => Is_String'Result =
(for all I in Item'Range => Is_Character (Item (I)));
-- Returns True if Is_Character(Item(I)) is True for each I in Item'Range.
------------------------------------------------------
-- Conversions between Wide_Character and Character --
------------------------------------------------------
-- Ada 2005 AI 395: these functions are moved to Ada.Characters.Conversions
-- and are considered obsolete in Ada.Characters.Handling. However we do
-- not complain about this obsolescence, since in practice it is necessary
-- to use these routines when creating code that is intended to run in
-- either Ada 95 or Ada 2005 mode.
-- We do however have to flag these if the pragma No_Obsolescent_Features
-- restriction is active (see Restrict.Check_Obsolescent_2005_Entity).
function To_Character
(Item : Wide_Character;
Substitute : Character := ' ') return Character
with
Post => To_Character'Result =
(if Is_Character (Item) then
Character'Val (Wide_Character'Pos (Item))
else
Substitute);
-- Returns the Character corresponding to Item if Is_Character(Item), and
-- returns the Substitute Character otherwise.
function To_String
(Item : Wide_String;
Substitute : Character := ' ') return String
with
Post => To_String'Result'First = 1
and then To_String'Result'Length = Item'Length
and then
(for all J in To_String'Result'Range =>
To_String'Result (J) =
To_Character (Item (Item'First + (J - 1)), Substitute));
-- Returns the String whose range is 1..Item'Length and each of whose
-- elements is given by To_Character of the corresponding element in Item.
function To_Wide_Character
(Item : Character) return Wide_Character
with
Post => To_Wide_Character'Result =
Wide_Character'Val (Character'Pos (Item));
-- Returns the Wide_Character X such that Character'Pos(Item) =
-- Wide_Character'Pos (X).
function To_Wide_String
(Item : String) return Wide_String
with
Post => To_Wide_String'Result'First = 1
and then To_Wide_String'Result'Length = Item'Length
and then
(for all J in To_Wide_String'Result'Range =>
To_Wide_String'Result (J) =
To_Wide_Character (Item (Item'First + (J - 1))));
-- Returns the Wide_String whose range is 1..Item'Length and each of whose
-- elements is given by To_Wide_Character of the corresponding element in
-- Item.
private
pragma Inline (Is_Alphanumeric);
pragma Inline (Is_Basic);
pragma Inline (Is_Character);
pragma Inline (Is_Control);
pragma Inline (Is_Digit);
pragma Inline (Is_Graphic);
pragma Inline (Is_Hexadecimal_Digit);
pragma Inline (Is_ISO_646);
pragma Inline (Is_Letter);
pragma Inline (Is_Line_Terminator);
pragma Inline (Is_Lower);
pragma Inline (Is_Mark);
pragma Inline (Is_Other_Format);
pragma Inline (Is_Punctuation_Connector);
pragma Inline (Is_Space);
pragma Inline (Is_Special);
pragma Inline (Is_Upper);
pragma Inline (To_Basic);
pragma Inline (To_Character);
pragma Inline (To_Lower);
pragma Inline (To_Upper);
pragma Inline (To_Wide_Character);
end Ada.Characters.Handling;
|
