hagen.pearl

/*
  Hagen in PEARL90
  English docs used: https://www.real-time.de/misc/PEARL90-LanguageReport-V2.2-GI-1998-eng.pdf
*/
MODULE (HAGEN);

SYSTEM; /* declare what system components we are using
           in this case, STDOUT with a log level of 2
           as the constant "TERMINAL" */
  TERMINAL:STDOUT;

PROBLEM; /* declare the algorithm to solve this automation problem
            which, descibes we will be using the constant TERMINAL
            externally, allowing us to use it in TASK */
  SPC TERMINAL DATION OUT ALPHIC DIM(,) TFU MAX FORWARD CONTROL (ALL);
  /* i've written these commands out as we would see them in english:
     SPC : specify TERMINAL as
     DATION : standard device/file i/o
     OUT : using standard output
     ALPHIC : only using alphanumeric characters
     DIM (,) : length of characters ("," meaning whatever given)
     TFU MAX : declare that each PUT should result in a new line (linefeed)
     FORWARD : only the following (forward) commands can access the device
     CONTROL (ALL) : iirc, checks to see if this device is still active and usable every 10 seconds */

  PROCEDURE;
    DECLARE true FIXED; ! declare the type of our variable "true"
    true := 1;          ! set it to the value of 1
  END;

  MAIN:TASK;
    WHILE true EQ 1            ! do booleans exist?
    REPEAT
      OPEN TERMINAL;           ! open writing
      PUT 'hagen' TO TERMINAL; ! print hagen
      CLOSE TERMINAL;          ! finish writing
    END;
  END;

MODEND;