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------------------------------------------------------------------------------
-- --
-- GNAT RUN-TIME COMPONENTS --
-- --
-- S Y S T E M . U T F _ 3 2 --
-- --
-- S p e c --
-- --
-- Copyright (C) 2005-2022, Free Software Foundation, Inc. --
-- --
-- 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. --
-- --
------------------------------------------------------------------------------
-- This package is an internal package that provides basic character
-- classification capabilities needed by the compiler for handling full
-- 32-bit wide wide characters. We avoid the use of the actual type
-- Wide_Wide_Character, since we want to use these routines in the compiler
-- itself, and we want to be able to compile the compiler with old versions
-- of GNAT that did not implement Wide_Wide_Character.
-- System.UTF_32 should not be directly used from an application program, but
-- an equivalent package GNAT.UTF_32 can be used directly and provides exactly
-- the same services. The reason this package is in System is so that it can
-- with'ed by other packages in the Ada and System hierarchies.
-- Note: this unit is used during bootstrap, see ADA_GENERATED_FILES in
-- gcc-interface/Make-lang.in for details on the constraints.
package System.UTF_32 is
pragma Pure;
type UTF_32 is range 0 .. 16#7FFF_FFFF#;
-- So far, the only defined character codes are in 0 .. 16#01_FFFF#
-- The following type defines the categories from the unicode definitions.
-- The one addition we make is Fe, which represents the characters FFFE
-- and FFFF in any of the planes.
type Category is (
Cc, -- Other, Control
Cf, -- Other, Format
Cn, -- Other, Not Assigned
Co, -- Other, Private Use
Cs, -- Other, Surrogate
Ll, -- Letter, Lowercase
Lm, -- Letter, Modifier
Lo, -- Letter, Other
Lt, -- Letter, Titlecase
Lu, -- Letter, Uppercase
Mc, -- Mark, Spacing Combining
Me, -- Mark, Enclosing
Mn, -- Mark, Nonspacing
Nd, -- Number, Decimal Digit
Nl, -- Number, Letter
No, -- Number, Other
Pc, -- Punctuation, Connector
Pd, -- Punctuation, Dash
Pe, -- Punctuation, Close
Pf, -- Punctuation, Final quote
Pi, -- Punctuation, Initial quote
Po, -- Punctuation, Other
Ps, -- Punctuation, Open
Sc, -- Symbol, Currency
Sk, -- Symbol, Modifier
Sm, -- Symbol, Math
So, -- Symbol, Other
Zl, -- Separator, Line
Zp, -- Separator, Paragraph
Zs, -- Separator, Space
Fe); -- relative position FFFE/FFFF in any plane
function Get_Category (U : UTF_32) return Category;
-- Given a UTF32 code, returns corresponding Category, or Cn if
-- the code does not have an assigned unicode category.
-- The following functions perform category tests corresponding to lexical
-- classes defined in the Ada standard. There are two interfaces for each
-- function. The second takes a Category (e.g. returned by Get_Category).
-- The first takes a UTF_32 code. The form taking the UTF_32 code is
-- typically more efficient than calling Get_Category, but if several
-- different tests are to be performed on the same code, it is more
-- efficient to use Get_Category to get the category, then test the
-- resulting category.
function Is_UTF_32_Letter (U : UTF_32) return Boolean;
function Is_UTF_32_Letter (C : Category) return Boolean;
pragma Inline (Is_UTF_32_Letter);
-- Returns true iff U is a letter that can be used to start an identifier,
-- or if C is one of the corresponding categories, which are the following:
-- Letter, Uppercase (Lu)
-- Letter, Lowercase (Ll)
-- Letter, Titlecase (Lt)
-- Letter, Modifier (Lm)
-- Letter, Other (Lo)
-- Number, Letter (Nl)
function Is_UTF_32_Digit (U : UTF_32) return Boolean;
function Is_UTF_32_Digit (C : Category) return Boolean;
pragma Inline (Is_UTF_32_Digit);
-- Returns true iff U is a digit that can be used to extend an identifier,
-- or if C is one of the corresponding categories, which are the following:
-- Number, Decimal_Digit (Nd)
function Is_UTF_32_Line_Terminator (U : UTF_32) return Boolean;
pragma Inline (Is_UTF_32_Line_Terminator);
-- Returns true iff U is an allowed line terminator for source programs,
-- if U is in the category Zp (Separator, Paragraph), or Zl (Separator,
-- Line), or if U is a conventional line terminator (CR, LF, VT, FF).
-- There is no category version for this function, since the set of
-- characters does not correspond to a set of Unicode categories.
function Is_UTF_32_Mark (U : UTF_32) return Boolean;
function Is_UTF_32_Mark (C : Category) return Boolean;
pragma Inline (Is_UTF_32_Mark);
-- Returns true iff U is a mark character which can be used to extend an
-- identifier, or if C is one of the corresponding categories, which are
-- the following:
-- Mark, Non-Spacing (Mn)
-- Mark, Spacing Combining (Mc)
function Is_UTF_32_Other (U : UTF_32) return Boolean;
function Is_UTF_32_Other (C : Category) return Boolean;
pragma Inline (Is_UTF_32_Other);
-- Returns true iff U is an other format character, which means that it
-- can be used to extend an identifier, but is ignored for the purposes of
-- matching of identifiers, or if C is one of the corresponding categories,
-- which are the following:
-- Other, Format (Cf)
function Is_UTF_32_Punctuation (U : UTF_32) return Boolean;
function Is_UTF_32_Punctuation (C : Category) return Boolean;
pragma Inline (Is_UTF_32_Punctuation);
-- Returns true iff U is a punctuation character that can be used to
-- separate pieces of an identifier, or if C is one of the corresponding
-- categories, which are the following:
-- Punctuation, Connector (Pc)
function Is_UTF_32_Space (U : UTF_32) return Boolean;
function Is_UTF_32_Space (C : Category) return Boolean;
pragma Inline (Is_UTF_32_Space);
-- Returns true iff U is considered a space to be ignored, or if C is one
-- of the corresponding categories, which are the following:
-- Separator, Space (Zs)
function Is_UTF_32_Non_Graphic (U : UTF_32) return Boolean;
function Is_UTF_32_Non_Graphic (C : Category) return Boolean;
pragma Inline (Is_UTF_32_Non_Graphic);
-- Returns true iff U is considered to be a non-graphic character, or if C
-- is one of the corresponding categories, which are the following:
-- Other, Control (Cc)
-- Other, Private Use (Co)
-- Other, Surrogate (Cs)
-- Separator, Line (Zl)
-- Separator, Paragraph (Zp)
-- FFFE or FFFF positions in any plane (Fe)
--
-- Note that the Ada category format effector is subsumed by the above
-- list of Unicode categories.
--
-- Note that Other, Unassigned (Cn) is quite deliberately not included
-- in the list of categories above. This means that should any of these
-- code positions be defined in future with graphic characters they will
-- be allowed without a need to change implementations or the standard.
--
-- Note that Other, Format (Cf) is also quite deliberately not included
-- in the list of categories above. This means that these characters can
-- be included in character and string literals.
-- The following function is used to fold to upper case, as required by
-- the Ada 2005 standard rules for identifier case folding. Two
-- identifiers are equivalent if they are identical after folding all
-- letters to upper case using this routine. A corresponding routine to
-- fold to lower case is also provided.
function Is_UTF_32_NFKC (U : UTF_32) return Boolean;
pragma Inline (Is_UTF_32_NFKC);
-- Return True if U could be present in a string normalized to
-- Normalization Form KC (as defined by Clause 21 of ISO/IEC 10646:2017),
-- otherwise returns False.
function Is_UTF_32_Basic (U : UTF_32) return Boolean;
pragma Inline (Is_UTF_32_Basic);
-- Return True if U has no Decomposition Mapping in the code charts of
-- ISO/IEC 10646:2017.
function UTF_32_To_Lower_Case (U : UTF_32) return UTF_32;
pragma Inline (UTF_32_To_Lower_Case);
-- If U represents an upper case letter, returns the corresponding lower
-- case letter, otherwise U is returned unchanged. The folding rule is
-- simply that if the code corresponds to a 10646 entry whose name contains
-- the string CAPITAL LETTER, and there is a corresponding entry whose name
-- is the same but with CAPITAL LETTER replaced by SMALL LETTER, then the
-- code is folded to this SMALL LETTER code. Otherwise the input code is
-- returned unchanged.
function UTF_32_To_Upper_Case (U : UTF_32) return UTF_32;
pragma Inline (UTF_32_To_Upper_Case);
-- If U represents a lower case letter, returns the corresponding lower
-- case letter, otherwise U is returned unchanged. The folding rule is
-- simply that if the code corresponds to a 10646 entry whose name contains
-- the string SMALL LETTER, and there is a corresponding entry whose name
-- is the same but with SMALL LETTER replaced by CAPITAL LETTER, then the
-- code is folded to this CAPITAL LETTER code. Otherwise the input code is
-- returned unchanged.
function UTF_32_To_Basic (U : UTF_32) return UTF_32;
pragma Inline (UTF_32_To_Basic);
-- Returns the UTF_32 character whose code point is given by the first
-- value of its Decomposition Mapping in the code charts of ISO/IEC
-- 10646:2017 if any; returns Item otherwise.
end System.UTF_32;