1------------------------------------------------------------------------------
2--                                                                          --
3--                         GNAT RUN-TIME COMPONENTS                         --
4--                                                                          --
5--              A D A . T E X T _ I O . G E N E R I C _ A U X               --
6--                                                                          --
7--                                 S p e c                                  --
8--                                                                          --
9--          Copyright (C) 1992-2009, Free Software Foundation, Inc.         --
10--                                                                          --
11-- GNAT is free software;  you can  redistribute it  and/or modify it under --
12-- terms of the  GNU General Public License as published  by the Free Soft- --
13-- ware  Foundation;  either version 3,  or (at your option) any later ver- --
14-- sion.  GNAT is distributed in the hope that it will be useful, but WITH- --
15-- OUT ANY WARRANTY;  without even the  implied warranty of MERCHANTABILITY --
16-- or FITNESS FOR A PARTICULAR PURPOSE.                                     --
17--                                                                          --
18-- As a special exception under Section 7 of GPL version 3, you are granted --
19-- additional permissions described in the GCC Runtime Library Exception,   --
20-- version 3.1, as published by the Free Software Foundation.               --
21--                                                                          --
22-- You should have received a copy of the GNU General Public License and    --
23-- a copy of the GCC Runtime Library Exception along with this program;     --
24-- see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see    --
25-- <http://www.gnu.org/licenses/>.                                          --
26--                                                                          --
27-- GNAT was originally developed  by the GNAT team at  New York University. --
28-- Extensive contributions were provided by Ada Core Technologies Inc.      --
29--                                                                          --
30------------------------------------------------------------------------------
31
32--  This package contains a set of auxiliary routines used by the Text_IO
33--  generic children, including for reading and writing numeric strings.
34
35private package Ada.Text_IO.Generic_Aux is
36
37   --  Note: for all the Load routines, File indicates the file to be read,
38   --  Buf is the string into which data is stored, Ptr is the index of the
39   --  last character stored so far, and is updated if additional characters
40   --  are stored. Data_Error is raised if the input overflows Buf. The only
41   --  Load routines that do a file status check are Load_Skip and Load_Width
42   --  so one of these two routines must be called first.
43
44   procedure Check_End_Of_Field
45     (Buf   : String;
46      Stop  : Integer;
47      Ptr   : Integer;
48      Width : Field);
49   --  This routine is used after doing a get operations on a numeric value.
50   --  Buf is the string being scanned, and Stop is the last character of
51   --  the field being scanned. Ptr is as set by the call to the scan routine
52   --  that scanned out the numeric value, i.e. it points one past the last
53   --  character scanned, and Width is the width parameter from the Get call.
54   --
55   --  There are two cases, if Width is non-zero, then a check is made that
56   --  the remainder of the field is all blanks. If Width is zero, then it
57   --  means that the scan routine scanned out only part of the field. We
58   --  have already scanned out the field that the ACVC tests seem to expect
59   --  us to read (even if it does not follow the syntax of the type being
60   --  scanned, e.g. allowing negative exponents in integers, and underscores
61   --  at the end of the string), so we just raise Data_Error.
62
63   procedure Check_On_One_Line (File : File_Type; Length : Integer);
64   --  Check to see if item of length Integer characters can fit on
65   --  current line. Call New_Line if not, first checking that the
66   --  line length can accommodate Length characters, raise Layout_Error
67   --  if item is too large for a single line.
68
69   function Getc (File : File_Type) return Integer;
70   --  Gets next character from file, which has already been checked for
71   --  being in read status, and returns the character read if no error
72   --  occurs. The result is EOF if the end of file was read. Note that
73   --  the Col value is not bumped, so it is the caller's responsibility
74   --  to bump it if necessary.
75
76   function Is_Blank (C : Character) return Boolean;
77   --  Determines if C is a blank (space or tab)
78
79   procedure Load_Width
80     (File  : File_Type;
81      Width : Field;
82      Buf   : out String;
83      Ptr   : in out Integer);
84   --  Loads exactly Width characters, unless a line mark is encountered first
85
86   procedure Load_Skip (File  : File_Type);
87   --  Skips leading blanks and line and page marks, if the end of file is
88   --  read without finding a non-blank character, then End_Error is raised.
89   --  Note: a blank is defined as a space or horizontal tab (RM A.10.6(5)).
90
91   procedure Load
92     (File   : File_Type;
93      Buf    : out String;
94      Ptr    : in out Integer;
95      Char   : Character;
96      Loaded : out Boolean);
97   --  If next character is Char, loads it, otherwise no characters are loaded
98   --  Loaded is set to indicate whether or not the character was found.
99
100   procedure Load
101     (File   : File_Type;
102      Buf    : out String;
103      Ptr    : in out Integer;
104      Char   : Character);
105   --  Same as above, but no indication if character is loaded
106
107   procedure Load
108     (File   : File_Type;
109      Buf    : out String;
110      Ptr    : in out Integer;
111      Char1  : Character;
112      Char2  : Character;
113      Loaded : out Boolean);
114   --  If next character is Char1 or Char2, loads it, otherwise no characters
115   --  are loaded. Loaded is set to indicate whether or not one of the two
116   --  characters was found.
117
118   procedure Load
119     (File   : File_Type;
120      Buf    : out String;
121      Ptr    : in out Integer;
122      Char1  : Character;
123      Char2  : Character);
124   --  Same as above, but no indication if character is loaded
125
126   procedure Load_Digits
127     (File   : File_Type;
128      Buf    : out String;
129      Ptr    : in out Integer;
130      Loaded : out Boolean);
131   --  Loads a sequence of zero or more decimal digits. Loaded is set if
132   --  at least one digit is loaded.
133
134   procedure Load_Digits
135     (File   : File_Type;
136      Buf    : out String;
137      Ptr    : in out Integer);
138   --  Same as above, but no indication if character is loaded
139
140   procedure Load_Extended_Digits
141     (File   : File_Type;
142      Buf    : out String;
143      Ptr    : in out Integer;
144      Loaded : out Boolean);
145   --  Like Load_Digits, but also allows extended digits a-f and A-F
146
147   procedure Load_Extended_Digits
148     (File   : File_Type;
149      Buf    : out String;
150      Ptr    : in out Integer);
151   --  Same as above, but no indication if character is loaded
152
153   function Nextc (File : File_Type) return Integer;
154   --  Like Getc, but includes a call to Ungetc, so that the file
155   --  pointer is not moved by the call.
156
157   procedure Put_Item (File : File_Type; Str : String);
158   --  This routine is like Text_IO.Put, except that it checks for overflow
159   --  of bounded lines, as described in (RM A.10.6(8)). It is used for
160   --  all output of numeric values and of enumeration values.
161
162   procedure Store_Char
163     (File : File_Type;
164      ch   : Integer;
165      Buf  : in out String;
166      Ptr  : in out Integer);
167   --  Store a single character in buffer, checking for overflow and
168   --  adjusting the column number in the file to reflect the fact
169   --  that a character has been acquired from the input stream. If
170   --  the character will not fit in the buffer it is stored in the
171   --  last character position of the buffer and Ptr is unchanged.
172   --  No exception is raised in this case, it is the caller's job
173   --  to raise Data_Error if the buffer fills up, so typically the
174   --  caller will make the buffer one character longer than needed.
175
176   procedure String_Skip (Str : String; Ptr : out Integer);
177   --  Used in the Get from string procedures to skip leading blanks in the
178   --  string. Ptr is set to the index of the first non-blank. If the string
179   --  is all blanks, then the exception End_Error is raised, Note that blank
180   --  is defined as a space or horizontal tab (RM A.10.6(5)).
181
182   procedure Ungetc (ch : Integer; File : File_Type);
183   --  Pushes back character into stream, using ungetc. The caller has
184   --  checked that the file is in read status. Device_Error is raised
185   --  if the character cannot be pushed back. An attempt to push back
186   --  an end of file (EOF) is ignored.
187
188private
189   pragma Inline (Is_Blank);
190
191end Ada.Text_IO.Generic_Aux;
192