MODULE TStrCat;
(* String concatenation `+` (arrays and literals, including a single
   CHAR operand) and string length. Exit 63. *)
VAR ExitCode : INTEGER;
VAR a : ARRAY [0 .. 31] OF CHAR;
VAR b, c : ARRAY [0 .. 7] OF CHAR;
BEGIN
  b[0] := "a"; b[1] := "b"; b[2] := CHR(0);
  c[0] := "c"; c[1] := "d"; c[2] := CHR(0);

  a := b + c;                     (* array + array -> "abcd" *)
  IF a = "abcd" THEN ExitCode := ExitCode + 1 ELSE ExitCode := 100 END;

  a := "xy" + "z";                (* literal + CHAR -> "xyz" *)
  IF a = "xyz" THEN ExitCode := ExitCode + 2 ELSE ExitCode := 100 END;

  a := "hello";                   (* string assignment (was a trap) *)
  IF a = "hello" THEN ExitCode := ExitCode + 4 ELSE ExitCode := 100 END;

  IF LEN(a) = 32 THEN ExitCode := ExitCode + 8 ELSE ExitCode := 100 END;
  IF LEN("hello") = 5 THEN ExitCode := ExitCode + 16 ELSE ExitCode := 100 END;
  IF LENGTH("abc") = 3 THEN ExitCode := ExitCode + 32 ELSE ExitCode := 100 END
END TStrCat.