| ------------------------------------------------------------------------------ |
| -- -- |
| -- GNAT COMPILER COMPONENTS -- |
| -- -- |
| -- W I D E C H A R -- |
| -- -- |
| -- S p e c -- |
| -- -- |
| -- Copyright (C) 1992-2022, 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. See the GNU General Public License -- |
| -- for more details. You should have received a copy of the GNU General -- |
| -- Public License distributed with GNAT; see file COPYING3. If not, go to -- |
| -- http://www.gnu.org/licenses for a complete copy of the license. -- |
| -- -- |
| -- GNAT was originally developed by the GNAT team at New York University. -- |
| -- Extensive contributions were provided by Ada Core Technologies Inc. -- |
| -- -- |
| ------------------------------------------------------------------------------ |
| |
| -- Subprograms for manipulation of wide character sequences. Note that in |
| -- this package, wide character and wide wide character are not distinguished |
| -- since this package is basically concerned with syntactic notions, and it |
| -- deals with Char_Code values, rather than values of actual Ada types. |
| |
| with Types; use Types; |
| |
| package Widechar is |
| |
| Wide_Char_Byte_Count : Nat := 0; |
| -- This value is incremented whenever Scan_Wide or Skip_Wide is called. |
| -- The amount added is the length of the wide character sequence minus |
| -- one. This means that the count that accumulates here represents the |
| -- difference between the length in characters and the length in bytes. |
| -- This is used for checking the line length in characters. |
| |
| function Length_Wide return Nat; |
| -- Returns the maximum length in characters for the escape sequence that |
| -- is used to encode wide character literals outside the ASCII range. Used |
| -- only in the implementation of the attribute Width for Wide_Character |
| -- and Wide_Wide_Character. |
| |
| procedure Scan_Wide |
| (S : Source_Buffer_Ptr; |
| P : in out Source_Ptr; |
| C : out Char_Code; |
| Err : out Boolean); |
| -- On entry S (P) points to the first character in the source text for |
| -- a wide character (i.e. to an ESC character, a left bracket, or an |
| -- upper half character, depending on the representation method). A |
| -- single wide character is scanned. If no error is found, the value |
| -- stored in C is the code for this wide character, P is updated past |
| -- the sequence and Err is set to False. If an error is found, then |
| -- P points to the improper character, C is undefined, and Err is |
| -- set to True. |
| |
| procedure Set_Wide |
| (C : Char_Code; |
| S : in out String; |
| P : in out Natural); |
| -- The escape sequence (including any leading ESC character) for the |
| -- given character code is stored starting at S (P + 1), and on return |
| -- P points to the last stored character (i.e. P is the count of stored |
| -- characters on entry and exit, and the escape sequence is appended to |
| -- the end of the stored string). The character code C represents a code |
| -- originally constructed by Scan_Wide, so it is known to be in a range |
| -- that is appropriate for the encoding method in use. |
| |
| procedure Skip_Wide (S : String; P : in out Natural); |
| -- On entry, S (P) points to an ESC character for a wide character escape |
| -- sequence or to an upper half character if the encoding method uses the |
| -- upper bit, or to a left bracket if the brackets encoding method is in |
| -- use. On exit, P is bumped past the wide character sequence. |
| |
| procedure Skip_Wide (S : Source_Buffer_Ptr; P : in out Source_Ptr); |
| -- Similar to the above procedure, but operates on a source buffer |
| -- instead of a string, with P being a Source_Ptr referencing the |
| -- contents of the source buffer. |
| |
| function Is_Start_Of_Wide_Char |
| (S : Source_Buffer_Ptr; |
| P : Source_Ptr) return Boolean; |
| -- Determines if S (P) is the start of a wide character sequence |
| |
| private |
| pragma Inline (Is_Start_Of_Wide_Char); |
| |
| end Widechar; |
