gm2-libs/PushBackInput

DEFINITION MODULE PushBackInput ;

FROM FIO IMPORT File ;
FROM DynamicStrings IMPORT String ;

EXPORT QUALIFIED Open, PutCh, GetCh, Error, WarnError, WarnString,
                 Close, SetDebug, GetExitStatus, PutStr,
                 PutString, GetColumnPosition, GetCurrentLine ;

(*
   Open - opens a file for reading.
*)

Open
PROCEDURE Open (a: ARRAY OF CHAR) : File ;

(*
   GetCh - gets a character from either the push back stack or
           from file, f.
*)

GetCh
PROCEDURE GetCh (f: File) : CHAR ;

(*
   PutCh - pushes a character onto the push back stack, it also
           returns the character which has been pushed.
*)

PutCh
PROCEDURE PutCh (ch: CHAR) : CHAR ;

(*
   PutString - pushes a string onto the push back stack.
*)

PutString
PROCEDURE PutString (a: ARRAY OF CHAR) ;

(*
   PutStr - pushes a dynamic string onto the push back stack.
            The string, s, is not deallocated.
*)

PutStr
PROCEDURE PutStr (s: String) ;

(*
   Error - emits an error message with the appropriate file, line combination.
*)

Error
PROCEDURE Error (a: ARRAY OF CHAR) ;

(*
   WarnError - emits an error message with the appropriate file, line combination.
               It does not terminate but when the program finishes an exit status of
               1 will be issued.
*)

WarnError
PROCEDURE WarnError (a: ARRAY OF CHAR) ;

(*
   WarnString - emits an error message with the appropriate file, line combination.
                It does not terminate but when the program finishes an exit status of
                1 will be issued.
*)

WarnString
PROCEDURE WarnString (s: String) ;

(*
   Close - closes the opened file.
*)

Close
PROCEDURE Close (f: File) ;

(*
   GetExitStatus - returns the exit status which will be 1 if any warnings were issued.
*)

GetExitStatus
PROCEDURE GetExitStatus () : CARDINAL ;

(*
   SetDebug - sets the debug flag on or off.
*)

SetDebug
PROCEDURE SetDebug (d: BOOLEAN) ;

(*
   GetColumnPosition - returns the column position of the current character.
*)

GetColumnPosition
PROCEDURE GetColumnPosition () : CARDINAL ;

(*
   GetCurrentLine - returns the current line number.
*)

GetCurrentLine
PROCEDURE GetCurrentLine () : CARDINAL ;

END PushBackInput.