MODULE Showcase11;
(* Standard-library tour: SysIO, TextIO, WholeIO, Strings, Math,
   Files. Reads one CARDINAL from stdin (e.g. 42).
   Prints: Modula-2 / 8 / 42 / 12 / 42 ; exit 80. *)

IMPORT Files;
FROM Files IMPORT File;
FROM Math IMPORT sqrt, Pi;
FROM Strings IMPORT Assign, Concat, Length;
FROM SysIO IMPORT Write, WriteInt, WriteLn;
FROM TextIO IMPORT WriteCard;
FROM WholeIO IMPORT ReadCard;

VAR ExitCode : INTEGER;
VAR s, t, u : ARRAY [0..31] OF CHAR;
VAR r : REAL;
VAR f : File;
VAR n : INTEGER;
VAR card : CARDINAL;

BEGIN
  (* Strings: build "Modula-2" and report its length. *)
  Assign("Modula", s);
  Assign("-2", t);
  Concat(s, t, u);
  Write(u);
  WriteLn;
  WriteInt(Length(u));           (* 8 *)
  WriteLn;

  (* WholeIO input + TextIO output: echo the read card. *)
  ReadCard(card);
  WriteCard(card);               (* 42 *)
  WriteLn;

  (* Math: sqrt(144) = 12. *)
  r := sqrt(144.0) + Pi - Pi;
  IF r > 11.9 THEN n := 12 ELSE n := 0 END;
  WriteInt(n);                   (* 12 *)
  WriteLn;

  (* Files: write two chars, read the integer back. *)
  f := Files.OpenWrite("gen_ssa/_showcase11.txt");
  Files.WriteChar(f, '4');
  Files.WriteChar(f, '2');
  Files.Close(f);
  f := Files.OpenRead("gen_ssa/_showcase11.txt");
  n := Files.ReadInt(f);
  Files.Close(f);
  WriteInt(n);                   (* 42 *)
  WriteLn;

  ExitCode := n - 12 + Length(u) + card
END Showcase11.