78 lines
4.6 KiB
Ada
78 lines
4.6 KiB
Ada
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------------------------------------------------------------------------------
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-- --
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-- GNAT RUN-TIME COMPONENTS --
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-- --
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-- A D A . S T R I N G S . U N B O U N D E D . A U X --
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-- --
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-- S p e c --
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-- --
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-- Copyright (C) 1992-2011, Free Software Foundation, Inc. --
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-- --
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-- GNAT is free software; you can redistribute it and/or modify it under --
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-- terms of the GNU General Public License as published by the Free Soft- --
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-- ware Foundation; either version 3, or (at your option) any later ver- --
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-- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
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-- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
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-- or FITNESS FOR A PARTICULAR PURPOSE. --
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-- --
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-- As a special exception under Section 7 of GPL version 3, you are granted --
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-- additional permissions described in the GCC Runtime Library Exception, --
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-- version 3.1, as published by the Free Software Foundation. --
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-- --
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-- You should have received a copy of the GNU General Public License and --
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-- a copy of the GCC Runtime Library Exception along with this program; --
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-- see the files COPYING3 and COPYING.RUNTIME respectively. If not, see --
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-- <http://www.gnu.org/licenses/>. --
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-- --
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-- GNAT was originally developed by the GNAT team at New York University. --
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-- Extensive contributions were provided by Ada Core Technologies Inc. --
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-- --
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------------------------------------------------------------------------------
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-- This child package of Ada.Strings.Unbounded provides some specialized
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-- access functions which are intended to allow more efficient use of the
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-- facilities of Ada.Strings.Unbounded, particularly by other layered
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-- utilities (such as GNAT.SPITBOL.Patterns).
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package Ada.Strings.Unbounded.Aux is
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pragma Preelaborate;
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subtype Big_String is String (1 .. Positive'Last);
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pragma Suppress_Initialization (Big_String);
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-- Type used to obtain string access to given address. Initialization is
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-- suppressed, since we never want to have variables of this type, and
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-- we never want to attempt initialiazation of virtual variables of this
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-- type (e.g. when pragma Normalize_Scalars is used).
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type Big_String_Access is access all Big_String;
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for Big_String_Access'Storage_Size use 0;
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-- We use this access type to pass a pointer to an area of storage to be
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-- accessed as a string. Of course when this pointer is used, it is the
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-- responsibility of the accessor to ensure proper bounds. The storage
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-- size clause ensures we do not allocate variables of this type.
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procedure Get_String
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(U : Unbounded_String;
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S : out Big_String_Access;
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L : out Natural);
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pragma Inline (Get_String);
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-- This procedure returns the internal string pointer used in the
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-- representation of an unbounded string as well as the actual current
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-- length (which may be less than S.all'Length because in general there
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-- can be extra space assigned). The characters of this string may be
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-- not be modified via the returned pointer, and are valid only as
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-- long as the original unbounded string is not accessed or modified.
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--
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-- This procedure is much more efficient than the use of To_String
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-- since it avoids the need to copy the string. The lower bound of the
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-- referenced string returned by this call is always one, so the actual
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-- string data is always accessible as S (1 .. L).
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procedure Set_String (UP : in out Unbounded_String; S : String_Access);
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pragma Inline (Set_String);
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-- This version of Set_Unbounded_String takes a string access value, rather
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-- than a string. The lower bound of the string value is required to be
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-- one, and this requirement is not checked.
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end Ada.Strings.Unbounded.Aux;
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