DEFINITION MODULE TextIO;

  (* Input and output of character and string types over specified channels.
     The read result is of the type IOConsts.ReadResults.
  *)

IMPORT IOChan;

  (* The following procedures do not read past line marks *)

PROCEDURE ReadChar (cid: IOChan.ChanId; VAR ch: CHAR);
  (* If possible, removes a character from the input stream cid and assigns the
     corresponding value to ch.  The read result is set to the value allRight, endOfLine, or
     endOfInput.
  *)

PROCEDURE ReadRestLine (cid: IOChan.ChanId; VAR s: ARRAY OF CHAR);
  (* Removes any remaining characters from the input stream cid before the next line mark,
     copying to s as many as can be accommodated as a string value. The read result is set
     to the value allRight, outOfRange, endOfLine, or endOfInput.
  *)

PROCEDURE ReadString (cid: IOChan.ChanId; VAR s: ARRAY OF CHAR);
  (* Removes only those characters from the input stream cid before the next line mark that
     can be accommodated in s as a string value, and copies them to s.  The read result is
     set to the value allRight, endOfLine, or endOfInput.
  *)

PROCEDURE ReadToken (cid: IOChan.ChanId; VAR s: ARRAY OF CHAR);
  (* Skips leading spaces, and then removes characters from the input stream cid before the
     next space or line mark, copying to s as many as can be accommodated as a string value.
     The read result is set to the value allRight, outOfRange, endOfLine, or endOfInput.
  *)

  (* The following procedure reads past the next line mark *)

PROCEDURE SkipLine (cid: IOChan.ChanId);
  (* Removes successive items from the input stream cid up to and including the next line
     mark, or until the end of input is reached.  The read result is set to the value
     allRight, or endOfInput.
  *)

  (* Output procedures *)

PROCEDURE WriteChar (cid: IOChan.ChanId; ch: CHAR);
  (* Writes the value of ch to the output stream cid. *)

PROCEDURE WriteLn (cid: IOChan.ChanId);
  (* Writes a line mark to the output stream cid. *)

PROCEDURE WriteString (cid: IOChan.ChanId; s: ARRAY OF CHAR);
  (* Writes the string value in s to the output stream cid. *)

END TextIO.

