Amiga ISO Collection/AmigaUtilCD2.iso/Misc/YADME10.LHA/YADME10/ARexx_docs/dmeARexxMac.doc

Text File | 1994-08-18 | 9.1 KB | 218 lines

This is the first general release (vX.29c), of Matt Dillon's DME editor
with an interface to Bill Hawes' ARexx REXX language interpreter, and is
functionally identical to Matt's v1.29c release (excepting the ARexx
interface, of course).

ARexx/REXX provides a powerful macro control language capability that can be
added to just about any application ... pretty easily, as it turns out.

I chose to add it's macro facilities to my favorite editor for a couple of
reasons.  First, as an exercise, to find out just how to interface ARexx to
an application, and second to make true named macros available to DME.

I think I've managed to do both, and would now like for other people to have
a bash at it, and see what I've overlooked.

With that in mind, here are a few, uh, implementation notes.  I solicit your
feedback.  Thanks!


     0 - The following included ARexx macros actually do something useful
     (though relatively simple).  They work, and are setup to process
     any ARexx generated or DME generated error conditions (such as
     not having enough room to save a file to).  At this time, some
         of the error messages that DME puts in the titlebar, may get
         overwritten by an "OK" message.  This is due to the limited number
         of changes that were made to the DME code, and should improve in
         subsequent releases.  See further remarks on error handling below.

     The useful macros are: save.dme, put.dme, putd.dme, get.dme, and
     bot.dme.  They are implementations of the VM/CMS XEDIT functions
     of the similar names.

     Any other included macros (.dme files) are mostly nonsense as far
     as functionallity.  They were used in helping be to help debug the
     interface, and are included only to illustrate some of the things
     one might do (like nested macro calls, etc).  So be kind about
     them :-)!


     1 - ARexx macros for DME must be named the same as the command string
     that will be be used to invoke them.


     2 - ARexx macros for DME should be given the filename extension ".dme".


     3 - ARexx macros for DME must reside in the current directory, or the
     directory "rexx:" is assigned to.  The current directory is searched
     first, followed by the "rexx:" directory.


     4 - ARexx macros for DME may be invoked in three ways:

     a - Explicitly, using one of the DME "rx" commands (e.g., "rx macname",
         "rx1 macname arg", or "rx2 macname arg1 arg2").

         The "rx" command is used to call an ARexx command without passing
         it any arguments; the "rx1" and "rx2" commands are used to pass
         the ARexx macro one or two arguments respectively.  If more args
         need to be passed to the ARexx macro, rx1 (or rx2) may be used by
         quoting them  E.g., to pass a macro 5 args, you might use the
         command: "rx2 macname (arg1 arg2) `arg3 arg4 arg5'", or possibly:
         "rx1 macname (arg1 arg2 arg3 arg4 arg5)".  The "args.dme" macro
         is included for you to experiment with.

         These forms may be embedded in a DME command string (e.g.,
         "bottom rx macname find foo" works), unlike the implicit form of
         invocation below.


     b - Implicitly, by specifying the name of a macro on DME's command
         line, followed by any arguments to be passed to the macro.

         The macro name must be the first (or only) token in the command
         string (e.g., "macname huey dewey louie"), and must NOT be the
         same as an internal DME command.

         Note that the entire command string is passed to the ARexx
         interperter "as is", with the case of any arguments, special
         characters, etc. being preserved.


     c - By keystroke.  The implicit form of a macro command line, with
         any arguments, may be mapped to a key just as a DME command is.
         Currently however, partial bindings are not supported.  That is,
         "escimm" cannot be used to bind the macro name to a key, leaving
         the argument(s), if any, to added in the command line.  This
         will be fixed in a future release.

         The explicit forms ("rx macname", etc.) may be bound in any
         command sequence.


     5 - Macro files may contain DME commands, or other macro names.  There
     is currently no "depth checking", nor checking for circular calls
     (A calls B, with B calling A).  If you create such things, you will
     probably get what you deserve :-)!

     Also, I think there is a problem in getting arguments for a second
     macro that are specified in the first macro passed back thru DME and
     on to the second macro.  I'm investigating this.

     Note that ARexx capitalizes arguments that are to be passed to DME
     if they are not quoted.  So if you want to give the command: find Foo,
     specify it as: find "Foo".  Otherwise you'll be looking for: FOO.


     6 - Hitting Ctrl-C will result in an "invalid message packet" error
     message from ARexx (code = 10).  This doesn't seem to cause any
     problems, but to avoid it, remap c-c to the new "null" command
     (which does absolutely nothing functional [i.e., map c-c `null'],
     or some other DME command.


     7 - I have not tested to see if explicit ARexx macro calls work inside
     of complex DME macros, nor with the $scanf facility.


     8 - Error handling is not all it should be.  Second level (or lower)
     macro error messages (in the title bar), may be overwritten by
     a higher level "OK" (or other message).

     Not all DME commands return completion codes, and the "sense" of
     them is opposite that of ARexx (in DME, failure = 0, success = 1).
     This makes figuring out who did what, what worked and what didn't,
     and what went wrong, a little difficult.  I'm sure I don't have it
     all "right" (and probably *can't* without alot of work to DME,
     which I explicitely don't want to do ... yet, anyway).

         I have the general definition of an error handling strategy roughed
         out (see the rexx.h file), but am still considering alternatives.
         This is likely to change, so don't count on the proposed method
         just yet.

     The binding to the ARexx ErrorMsg() function isn't working with
     Manx yet (because I need to change the "rexxglue" binding, I think).
     So right now I don't display the actual ARexx error messages, and
     have to give you just the code.

     This whole area needs lots of work ...


     9 - Yes, I know the title bar blinking while a macro is running can be
     distracting.  At least you can sorta see what's happening if *you*
     don't blink :-).


    10 - Compiled using Manx v3.60a (v3.40a/b works too).


    11 - To compile, set AREXX to 1 in defs.h, and "make rexx".  Set AREXX
         to 0, and use "make norexx"  to create a non-ARexx, vanilla version.

     The Makefiles assume you have a precompiled header file in vd0:include
     called "symbols.m" (all of the Amiga .h's).  Also you need to have
     the rexx includes in the "include/rexx" directory, and Matt's sup32lib
         includes in "include/sup32".  His "sup32.lib" should be in the current
     directory, or in the directory with teh Manx libs.

     For linking, the "rexxbind.o" file is needed.  When make processes
     "rexxbind.asm", you'll need to be sure your assembly language .i
         files are available to the assembler.


    12 - The ARexx interface adds about 1.5K to the size of the executable
     right now.

     This can probably be reduced a little, by removing some of the checking
         done in "rexx.c" following some of the calls to the ARexx functions
         that create/initialize the messages sent to ARexx.  They're just in
         there for CYA at the moment (I think).


    13 - This implementation uses the COMMAND interface described in the
     ARexx documentation (as opposed to the FUNCTION interface).


    14 - ARexx is a Copyrighted product by William S. Hawes,  PO Box 308,
     Maynard, MA  01754 (617-568-8695), and is available from him with
     complete documentation for $49.95 U.S. (plus $2 shipping).

     It is a very good product, and well worth the money.  *Please* do
     not pirate it!  I've received written permission from Bill allowing
     the redistribution of his include files with DME, or other example
     code, however please note that these files are still Copyrighted
     by Bill, and that if *you* want to distribute them with *your* own
         application, you should obtain your own permission from Bill to
         do so.


    15 - DME is a Copyrighted, freely redistributable program by Matt
     Dillon, of Berkeley, CA.  It may be distributed for non-profit
     only.    Obviously, I think it's the best editor currently available
     for the Amiga ... otherwise I wouldn't have gone to the trouble to
     add the ARexx interface.

     My code falls under the same distribution restrictions as Matt's;
     you may redistribute it freely, but may not use it for profit, nor
     imbed it in a commercial product without prior written permission
     from me.


    16 - Please report any problems or bugs found in this version to me at
     the address below, and don't bug Matt about them.  He doesn't have
     ARexx (yet), and won't be able to help you out.


Good luck ... I hope you find the ARexx interface a useful enhancement!

/kim   03/31/88


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