Simtel MSDOS 1992 September/Simtel20_Sept92.cdr/msdos/pascal/mystic.arc/PAS2.DOC

Text File | 1986-02-27 | 12KB | 344 lines

        Mystic Pascal  User Manual                                      12


        3.  Full Screen Editor

             Mystic  Pascal  provides a full screen editor which is  used
        for  entering,  modifying and inspecting Pascal source  programs.
        It is not intended for editing other types of files.

             You can edit your Pascal program as a text file although the
        editor stores the program in a "tokenized" format.   A token is a
        one byte code which can represent an entire Pascal reserved word.
        For  example,  the  reserved word PROCEDURE uses 9 bytes in  text
        format  but only one byte in token format.   Obviously a  typical
        Pascal program can be greatly compressed by using token format.

             The  editor converts all identifiers to upper case  when  it
        stores  them  in  its table.   You can use an  option  switch  to
        control  whether  reserved words,  standard identifiers and  user
        defined identifiers are displayed in lower or upper case.  (Refer
        to   section  4.1  of  this  manual.)    For  example,   the  two
        identifiers "Initialize" and "INITIALIZE" are treated as the same
        identifier.

             Source  programs  must  not contain lines  greater  than  80
        characters, the width of the standard display screen.





























        Section 3:   Full Screen Editor

        Mystic Pascal  User Manual                                      13


        3.1  Loading and Saving Pascal Programs

             When you want to work on a Pascal program which is saved  on
        disk,  you  must load it into Mystic Pascal.   To load a  program
        from  disk,  go  to  the Editor screen.   (F1 is used  to  switch
        between  the different screens.)  If you are in the  Editor,  hit
        F2.  This will display the Editor command menu.  Select command L
        for load.    You will be asked the name of the file to be loaded.
        The 3 character filetype must be keyed in with the filename.   It
        does not assume any default filetype.   A disk letter prefix  may
        be added to access files not on the current disk drive.

             Sample filenames with filetypes:
                  TEST.PAS            c:stock.mdl
                  Startrek.bak        b:Train.set

             If the file is not found or there is some other  error,  the
        error  message  will  be  displayed and you may  then  retry  the
        operation.

             To  save  a  the Pascal program currently  residing  in  the
        editor is a nearly identical process.  Enter F2, then S, then the
        filename.filetype.   The filename need not be the same as in  the
        last Load command.



        3.2  Entering a New Pascal Program

             When  Mystic Pascal is first started the editor is empty and
        a new program may be directly keyed in.  If there is a program in
        the editor and you wish to enter a new program,  key F2,  then N.
        This  command clears out the editor.   Any program in the  editor
        buffer is cleared out of the buffer by the New command.  You  can
        use the Save command to save such a program first.

















        Section 3:   Full Screen Editor

        Mystic Pascal  User Manual                                      14


        3.3  Editing Commands

             Mystic  Pascal  editing commands are used to modify text  on
        the CRT screen for the current Pascal program.   Many people  are
        experienced  with the Wordstar word processing  program.   Mystic
        Pascal's edit commands are similar to those commands.


        3.3.1  Cursor Movement Commands

        right one character           Control D      right arrow
        left one character            Control S      left arrow
        up one line                   Control E      up arrow
        down one line                 Control X      down arrow
        right one word                Control F      Control right arrow
        left one word                 Control A      Control left arrow
        top of file                   Home
        end of file                   End
        tab                           Tab
        reverse tab                   Shift Tab
        next line                     return


        3.3.2  Scroll Commands

        scroll up one line            Control Z
        scroll down one line          Control W
        scroll up one page            Control C      PgUp
        scroll down one page          Control R      PgDn


        3.3.3  Insert and Delete Commands

        insert mode toggle            Control V      Ins
        insert new line               Control N
        delete character              Control G      Del
        destructive backspace         Control H      right arrow key 14
        delete word right             Control T
        delete line                   Control Y













        Section 3:   Full Screen Editor

        Mystic Pascal  User Manual                                      15


        3.4  Compiling a Pascal Program

             To  compile a Pascal program you must first load it into the
        editor.   Generally a program you are working on will already  be
        in the editor.

             Once  your  program  is  loaded and you are  in  the  editor
        screen,  then to compile the program, enter key F2 then letter C.
        If  the  compile has no errors,  a small window will display  the
        elapsed  time of the compile and the compiler speed in lines  per
        second.   The size of the code generated is also displayed.   Hit
        any key to remove the window.

             To compile, enter

                  F2   then    C

             If  there  is an error during the  compile,  the  cursor  is
        positioned  at the location of the error (or just past it) in the
        source program.  An error message is displayed in a small window.
        Hit any key to remove the window and resume editing.  Correct the
        error and you can then recompile.



        Technical Notes

              Mystic  Pascal  uses an advanced compiler  architecture  to
        achieve very high compile speed.  The "Lines per second" value is
        intended  to show the effective compilation speed for  comparison
        with other compilers.

             The  compiler  elapsed time is measured using  the  Personal
        Computer's  timer tick interrupt which occurs every 0.055  second
        (18.2  times per second).   If,  by chance,  no timer ticks occur
        between the start and finish of the compilation,  then the actual
        time must have been between 0.0 and 0.055 second.   In this case,
        the elapsed time is adjusted to 0.030 second,  a middle value, to
        avoid division by zero in computing the lines per second.



        3.5  EXE File Create                                ** 1.6 **

             After   a  Pascal  program  has  successfully  compiled,   a
        standalone  EXE file version of the program may be  created  with
        the 'E' command on the F2 menu.





        Section 3:   Full Screen Editor

        Mystic Pascal  User Manual                                      16


        4.  Direct Mode

             In the Direct Mode screen,  Pascal statements may be entered
        directly.   They are instantly compiled, executed and any results
        displayed.

             The  statements are compiled at the global level.   You  can
        access  all  global variables,  procedures and functions but  not
        those  declared within a procedure or function.   Each  statement
        must fit on one line.   Multiple statements may be entered on one
        line.

             The backslash "\" is the prompt character.

             To run the entire program,  type the program's name which is
        declared in the program header.

             Since  many  Direct Mode statements will use  the  procedure
        WRITE  to display the value of variables,  an abbreviated form is
        provided.

             .X, Y, Z       is equivalent to
             WRITE(X, Y, Z)

             When using the dot print command,  no other statements  must
        appear on the line and the dot must be the first character.



        4.1  Case Control

             The  #CASE  command controls the display of upper and  lower
        case in the editor screen and for the Save command.   Three types
        of  words  - reserved words,  predefined  identifiers  and  user-
        declared  identifiers - may be displayed in either upper or lower
        case.  The #CASE command is keyed into the Direct Mode screen.

             The format is:

                  #CASE=abc

             a,  b and c may be either 'U' or 'L'.   No spaces or  commas
        are allowed in this command.

             a = reserved word case
             b = predefined identifiers case
             c = user-declared identifiers case

             The initial setting is  #CASE=ULL.



        Section 4:   Direct Mode

        Mystic Pascal  User Manual                                      17



        4.2  Video Snow

             The IBM Color Adapter may produce video noise or "snow" when
        the video memory is directly updated.   Mystic Pascal does access
        the  video memory directly because this is many times faster than
        operating  through DOS.   Mystic Pascal is able to  suppress  the
        snow  effect,  but  this may greatly slow down the display  speed
        since screen updates may only be done during vertical retrace.

             Snow suppression is automatically turned on when running  on
        the  Color  card.   Snow  suppression may be  suppressed  by  the
        Mysticin installation program,  because some IBM compatible color
        cards  do  not produce snow and should not be forced to  pay  the
        speed penalty.

             Snow  suppression  may also be toggled on and off  with  the
        #SNOW command in Direct Mode.  Do not use this command if a color
        card is not present!   Color card users can easily see the effect
        of snow suppression by trying this command and then examining the
        System Display screen.


        4.3  Intermediate Code Listing

             The  Mystic  Pascal  compiler  parser  outputs  intermediate
        codes.  The code generator then converts these "icodes" into 8086
        object code.  Mystic's first optimizer operates on the icodes and
        the second optimizer operates on the 8086 code.

             The  #LIST  command produces a listing of the icodes on  the
        printer.   This  listing is only for informational  purposes  for
        hackers and other curious people.

             The formats are:

             #LIST = 1      Turn on Icode listing
             #LIST = 0      Turn off Icode listing

             Warning!   The Icode listing for a large program can be VERY
        long and may not be interrupted once begun.


        4.4  Clear Screen Command

             In  Direct  Mode the screen may be cleared by  entering  '#'
        followed by a return.





        Section 4:   Direct Mode