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1 ------------------------------------------------------------------------------
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2 -- --
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3 -- GNAT RUN-TIME COMPONENTS --
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4 -- --
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5 -- 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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6 -- --
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7 -- S p e c --
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8 -- --
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131
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9 -- Copyright (C) 1992-2018, Free Software Foundation, Inc. --
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111
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10 -- --
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11 -- GNAT is free software; you can redistribute it and/or modify it under --
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12 -- terms of the GNU General Public License as published by the Free Soft- --
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13 -- ware Foundation; either version 3, or (at your option) any later ver- --
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14 -- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
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15 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
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16 -- or FITNESS FOR A PARTICULAR PURPOSE. --
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17 -- --
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18 -- As a special exception under Section 7 of GPL version 3, you are granted --
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19 -- additional permissions described in the GCC Runtime Library Exception, --
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20 -- version 3.1, as published by the Free Software Foundation. --
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21 -- --
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22 -- You should have received a copy of the GNU General Public License and --
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23 -- a copy of the GCC Runtime Library Exception along with this program; --
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24 -- see the files COPYING3 and COPYING.RUNTIME respectively. If not, see --
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25 -- <http://www.gnu.org/licenses/>. --
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26 -- --
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27 -- GNAT was originally developed by the GNAT team at New York University. --
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28 -- Extensive contributions were provided by Ada Core Technologies Inc. --
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29 -- --
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30 ------------------------------------------------------------------------------
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31
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32 -- This child package of Ada.Strings.Unbounded provides some specialized
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33 -- access functions which are intended to allow more efficient use of the
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34 -- facilities of Ada.Strings.Unbounded, particularly by other layered
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35 -- utilities (such as GNAT.SPITBOL.Patterns).
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36
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37 package Ada.Strings.Unbounded.Aux is
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38 pragma Preelaborate;
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39
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40 subtype Big_String is String (1 .. Positive'Last);
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41 pragma Suppress_Initialization (Big_String);
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42 -- Type used to obtain string access to given address. Initialization is
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43 -- suppressed, since we never want to have variables of this type, and
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44 -- we never want to attempt initialiazation of virtual variables of this
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45 -- type (e.g. when pragma Normalize_Scalars is used).
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46
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47 type Big_String_Access is access all Big_String;
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48 for Big_String_Access'Storage_Size use 0;
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49 -- We use this access type to pass a pointer to an area of storage to be
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50 -- accessed as a string. Of course when this pointer is used, it is the
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51 -- responsibility of the accessor to ensure proper bounds. The storage
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52 -- size clause ensures we do not allocate variables of this type.
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53
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54 procedure Get_String
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55 (U : Unbounded_String;
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56 S : out Big_String_Access;
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57 L : out Natural);
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58 pragma Inline (Get_String);
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59 -- This procedure returns the internal string pointer used in the
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60 -- representation of an unbounded string as well as the actual current
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61 -- length (which may be less than S.all'Length because in general there
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62 -- can be extra space assigned). The characters of this string may be
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63 -- not be modified via the returned pointer, and are valid only as
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64 -- long as the original unbounded string is not accessed or modified.
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65 --
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66 -- This procedure is much more efficient than the use of To_String
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67 -- since it avoids the need to copy the string. The lower bound of the
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68 -- referenced string returned by this call is always one, so the actual
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69 -- string data is always accessible as S (1 .. L).
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70
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71 procedure Set_String (UP : in out Unbounded_String; S : String_Access);
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72 pragma Inline (Set_String);
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73 -- This version of Set_Unbounded_String takes a string access value, rather
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74 -- than a string. The lower bound of the string value is required to be
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75 -- one, and this requirement is not checked.
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76
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77 end Ada.Strings.Unbounded.Aux;
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