File : a-tigeau.ads


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     ------------------------------------------------------------------------------
  35 
     --  This package contains a set of auxiliary routines used by the Text_IO
     --  generic children, including for reading and writing numeric strings.
     
     private package Ada.Text_IO.Generic_Aux is
  40 
        --  Note: for all the Load routines, File indicates the file to be read,
        --  Buf is the string into which data is stored, Ptr is the index of the
        --  last character stored so far, and is updated if additional characters
        --  are stored. Data_Error is raised if the input overflows Buf. The only
  45    --  Load routines that do a file status check are Load_Skip and Load_Width
        --  so one of these two routines must be called first.
     
        procedure Check_End_Of_Field
          (Buf   : String;
  50       Stop  : Integer;
           Ptr   : Integer;
           Width : Field);
        --  This routine is used after doing a get operations on a numeric value.
        --  Buf is the string being scanned, and Stop is the last character of
  55    --  the field being scanned. Ptr is as set by the call to the scan routine
        --  that scanned out the numeric value, i.e. it points one past the last
        --  character scanned, and Width is the width parameter from the Get call.
        --
        --  There are two cases, if Width is non-zero, then a check is made that
  60    --  the remainder of the field is all blanks. If Width is zero, then it
        --  means that the scan routine scanned out only part of the field. We
        --  have already scanned out the field that the ACVC tests seem to expect
        --  us to read (even if it does not follow the syntax of the type being
        --  scanned, e.g. allowing negative exponents in integers, and underscores
  65    --  at the end of the string), so we just raise Data_Error.
     
        procedure Check_On_One_Line (File : File_Type; Length : Integer);
        --  Check to see if item of length Integer characters can fit on
        --  current line. Call New_Line if not, first checking that the
  70    --  line length can accommodate Length characters, raise Layout_Error
        --  if item is too large for a single line.
     
        function Getc (File : File_Type) return Integer;
        --  Gets next character from file, which has already been checked for
  75    --  being in read status, and returns the character read if no error
        --  occurs. The result is EOF if the end of file was read. Note that
        --  the Col value is not bumped, so it is the caller's responsibility
        --  to bump it if necessary.
     
  80    function Is_Blank (C : Character) return Boolean;
        --  Determines if C is a blank (space or tab)
     
        procedure Load_Width
          (File  : File_Type;
  85       Width : in Field;
           Buf   : out String;
           Ptr   : in out Integer);
        --  Loads exactly Width characters, unless a line mark is encountered first
     
  90    procedure Load_Skip (File  : File_Type);
        --  Skips leading blanks and line and page marks, if the end of file is
        --  read without finding a non-blank character, then End_Error is raised.
        --  Note: a blank is defined as a space or horizontal tab (RM A.10.6(5)).
     
  95    procedure Load
          (File   : File_Type;
           Buf    : out String;
           Ptr    : in out Integer;
           Char   : Character;
 100       Loaded : out Boolean);
        --  If next character is Char, loads it, otherwise no characters are loaded
        --  Loaded is set to indicate whether or not the character was found.
     
        procedure Load
 105      (File   : File_Type;
           Buf    : out String;
           Ptr    : in out Integer;
           Char   : Character);
        --  Same as above, but no indication if character is loaded
 110 
        procedure Load
          (File   : File_Type;
           Buf    : out String;
           Ptr    : in out Integer;
 115       Char1  : Character;
           Char2  : Character;
           Loaded : out Boolean);
        --  If next character is Char1 or Char2, loads it, otherwise no characters
        --  are loaded. Loaded is set to indicate whether or not one of the two
 120    --  characters was found.
     
        procedure Load
          (File   : File_Type;
           Buf    : out String;
 125       Ptr    : in out Integer;
           Char1  : Character;
           Char2  : Character);
        --  Same as above, but no indication if character is loaded
     
 130    procedure Load_Digits
          (File   : File_Type;
           Buf    : out String;
           Ptr    : in out Integer;
           Loaded : out Boolean);
 135    --  Loads a sequence of zero or more decimal digits. Loaded is set if
        --  at least one digit is loaded.
     
        procedure Load_Digits
          (File   : File_Type;
 140       Buf    : out String;
           Ptr    : in out Integer);
        --  Same as above, but no indication if character is loaded
     
        procedure Load_Extended_Digits
 145      (File   : File_Type;
           Buf    : out String;
           Ptr    : in out Integer;
           Loaded : out Boolean);
        --  Like Load_Digits, but also allows extended digits a-f and A-F
 150 
        procedure Load_Extended_Digits
          (File   : File_Type;
           Buf    : out String;
           Ptr    : in out Integer);
 155    --  Same as above, but no indication if character is loaded
     
        function Nextc (File : File_Type) return Integer;
        --  Like Getc, but includes a call to Ungetc, so that the file
        --  pointer is not moved by the call.
 160 
        procedure Put_Item (File : File_Type; Str : String);
        --  This routine is like Text_IO.Put, except that it checks for overflow
        --  of bounded lines, as described in (RM A.10.6(8)). It is used for
        --  all output of numeric values and of enumeration values.
 165 
        procedure Store_Char
          (File : File_Type;
           ch   : Integer;
           Buf  : out String;
 170       Ptr  : in out Integer);
        --  Store a single character in buffer, checking for overflow and
        --  adjusting the column number in the file to reflect the fact
        --  that a character has been acquired from the input stream.
     
 175    procedure String_Skip (Str : String; Ptr : out Integer);
        --  Used in the Get from string procedures to skip leading blanks in the
        --  string. Ptr is set to the index of the first non-blank. If the string
        --  is all blanks, then the excption End_Error is raised, Note that blank
        --  is defined as a space or horizontal tab (RM A.10.6(5)).
 180 
        procedure Ungetc (ch : Integer; File : File_Type);
        --  Pushes back character into stream, using ungetc. The caller has
        --  checked that the file is in read status. Device_Error is raised
        --  if the character cannot be pushed back. An attempt to push back
 185    --  an end of file (EOF) is ignored.
     
     private
        pragma Inline (Is_Blank);
     
 190 end Ada.Text_IO.Generic_Aux;