Package: Ada.Text_IO.Generic

Package: Ada.Text_IO.Generic_Aux

Description

This package contains a set of auxiliary routines used by the Text_IO generic children, including for reading and writing numeric strings. 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 Load routines that do a file status check are Load_Skip and Load_Width so one of these two routines must be called first.

Header

package Ada.Text_IO.Generic_Aux is

Other Items:

procedure Check_End_Of_Field
  (File  : File_Type;
   Buf   : String;
   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 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 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 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 line length can accomodate 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 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.

function Is_Blank (C : Character) return Boolean;

Determines if C is a blank (space or tab)

procedure Load_Width
  (File  : File_Type;
   Width : in Field;
   Buf   : out String;
   Ptr   : in out Integer);

Loads exactly Width characters, unless a line mark is encountered first

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)).

procedure Load
  (File   : File_Type;
   Buf    : out String;
   Ptr    : in out Integer;
   Char   : Character;
   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
  (File   : File_Type;
   Buf    : out String;
   Ptr    : in out Integer;
   Char   : Character);

Same as above, but no indication if character is loaded

procedure Load
  (File   : File_Type;
   Buf    : out String;
   Ptr    : in out Integer;
   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 characters was found.

procedure Load
  (File   : File_Type;
   Buf    : out String;
   Ptr    : in out Integer;
   Char1  : Character;
   Char2  : Character);

Same as above, but no indication if character is loaded

procedure Load_Digits
  (File   : File_Type;
   Buf    : out String;
   Ptr    : in out Integer;
   Loaded : out Boolean);

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;
   Buf    : out String;
   Ptr    : in out Integer);

Same as above, but no indication if character is loaded

procedure Load_Extended_Digits
  (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

procedure Load_Extended_Digits
  (File   : File_Type;
   Buf    : out String;
   Ptr    : in out Integer);

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.

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.

procedure Store_Char
  (File : File_Type;
   ch   : Integer;
   Buf  : out String;
   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.

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)).

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 an end of file (EOF) is ignored.

private

   --  Implementation-defined ...

end Ada.Text_IO.Generic_Aux;