From: rurban@x-ray.at (Reini Urban)
Newsgroups: comp.cad.autocad,alt.cad.autocad,alt.answers,comp.answers,news.answers
Subject: comp.cad.autocad AutoLISP FAQ (part 1/2) - general
Reply-To: rurban@xarch.tu-graz.ac.at (Reini Urban)
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Keywords: FAQ, AutoLISP, AutoCAD
Summary: AutoLISP is a scripting language for AutoCAD, a wellknown CAD 
  package. This AutoLISP FAQ is posted to comp.cad.autocad, alt.cad.autocad 
  and *.answers monthly.
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Posted-By: auto-faq 3.2.1.5
Archive-name: CAD/autolisp-faq/part1
URL: http://xarch.tu-graz.ac.at/autocad/news/faq/autolisp.html
Version: 2.28
Last-modified: 2002-06-25
Posted-By: Reini Urban <rurban@x-ray.at>
Posting-Frequency: monthly
Copyright: see Appendix [A]

        Welcome to the comp.cad.autocad AutoLISP FAQ
          by Reini Urban <rurban@x-ray.at>

Autolisp is a scripting language for AutoCAD, a well known CAD package. 
This AutoLISP FAQ is posted to comp.cad.autocad, alt.cad.autocad and
the *.answers groups monthly. Some AutoCAD FAQ's are at
http://www.autodesk.com/support/autocad/ but not posted to
comp.cad.autocad. The contents and the samples apply to all
releases of AutoLISP since Release 10, including Visual Lisp, Vital Lisp
and ACOMP. There's no special AutoLISP newsgroup.
Best are comp.cad.autocad and autodesk.autocad.customization,
but please don't bother comp.lang.lisp.
Source code of all functions in this FAQ is in FAQ-CODE.LSP
(for location see [A.1]), there's also a Winhelp file.
Thanks to all who have contributed. Corrections and contributions
always welcome. 
Please see http://xarch.tu-graz.ac.at/acadwiki/RulesToLiveBy

This is part 1/2 of the AutoLISP FAQ v2.28, which consists of:

    AutoLISP FAQ (part 1/2) - General
    AutoLISP FAQ (part 2/2) - Samples, code

| changes, + new in items from this version to the last posted version,
intermediate personal comments and uncertainties in <..>

  -----------------
  Table of Contents
  -----------------
  part 1:   General
     [0] The Future of AutoLISP? Should I learn it or VB instead?
       [0.1] What changed with AutoCAD 2000?
       [0.2] We cannot create ARX anymore?
     [1] Where can I find AutoLISP routines on the Internet?
       [1.1] Are the comp.cad.autocad articles stored somewhere?
       [1.2] Autodesk's SDK
     [2] What are the best books to learn AutoLISP?
       [2.1] Online AutoLISP documents, Winhelp [deleted]
       [2.2] AutoLISP Coding Style
     [3] How do I debug AutoLISP programs?
        [3.1] Native AutoLISP debuggers
        [3.2] Modular style, TRACE
        [3.3] BREAK function, debug-print
     [4] How can I protect my AutoLISP programs? Security
       [4.1] Kelvinate
       [4.2] Protect
       [4.3] Kelvinate and Protect
       [4.4] Convert
       [4.5] ACOMP
       [4.7] Lisp2C
       [4.6] Vital LISP Professional
       [4.8] Visual Lisp by Autodesk
     [5] AutoLISP compilers
       [5.1] ACOMP
       [5.2] Vital LISP Professional
       [5.3] Visual Lisp by Autodesk
       [5.4] Better ones: Common Lisp and Scheme
     [6] AutoLISP editors and other tools
       [6.1] AutoLISP editors
       [6.2] Analyzers, Packager and Parenthesis checkers
       [6.3] Pretty Printers
     [7] AutoLISP problems and bugs
     [8] Sorting with AutoLISP
     [9] Recursion
     [10] Iteration with MAPCAR,...
+    [11] S::STARTUP, My LISPs aren't loading at startup anymore
     [12] How to AUTOLOAD my programs?
     [13] How can I pass a variable number of
          arguments to a LISP function?
     [14] How can I avoid stack overflows?
     [15] (command "ROTATE3D") does not work! Why?
     [16] Lisp programs operating over multiple drawings
     [17] How to export Visual Lisp functions to AutoLISP/AutoCAD?
     --
     [A] Disclaimer, Notes from the authors
       [A.1] FAQ Locations

  part 2:   Samples, code
     [20] General Helper functions
       [20.1] List manipulation
       [20.2] String manipulation
       [20.3] symbol->string
       [20.4] AutoCAD entity access
     [21] Sample Lisp programs
       [21.1] Globally change text, polylines, layer utils, date stamp
       [21.2] Plot dialog from within LISP. Using DDE or ActiveX
       [21.3] (entmod),(entmake) Layers, without (command "_LAYER"...)
       [21.4] How to select multiple files in LISP? (as in FILES-Unlock)
       [21.5] Replace multiple blocks
       [21.6] (vports), VIEWPORT entity, pixel conversion
       [21.7] Select all visible objects: zoom coordinates
       [21.8] How to write XYZ data of selected objects to a file?
     [22] Block Attributes
       [22.1] How to access block attributes?
       [22.2] How to MODIFY block attributes? DATESTAMP.LSP
       [22.3] How to UPDATE block attributes?
       [22.4] How to ENTMAKE a Block Complex Entity in AutoLISP
     [23] Polylines
       [23.1] How to access polyline VERTICES?
       [23.2] How to JOIN multiple lines to polylines?
       [23.3] Change WIDTH of multiple polylines
       [23.4] Create a polyline or spline: with (ENTMAKE) or (COMMAND)
       [23.5] How to calculate the LENGTH of polylines?
       [23.6] How to revert the polyline direction?
       [23.7] How to get the CENTER of a polyline?
     [24] Circle/Arc Geometry:  BULGE conversion, some trigonometry
     [25] DCL: listboxes with tabs or monotext font
     [26] EED Extended Entity Data: Get and Store
       [26.1] Select objects on their EED with (ssget "X")
       [26.2] Get EED from an object
     [27] How to break a command in LISP?
       [27.1] How to do an unlimited number user prompts?
     [28] How to decode ACIS internal geometry with LISP
     --
     [A] Disclaimer, Notes from the author
+      [A.1] FAQ Locations
     [B] Acknowledgements
     [C] Recent Changes

----------------------------------------------------------------------
Subject: [0] The Future of AutoLISP? Should I learn it or VB instead?

  AutoLISP will be definitely supported in future releases.
  VB was introduced to simplify Office Automation: ACAD <-> Excel/Access
  Both languages have advantages and disadvantages. You should take a look
  at both. VB seems to be more graphical and AutoLISP more logical. The
  object concept of VBA seems to be easier to learn, but you cannot run
  commands like in AutoLISP. The new VBA (>= R14.01) is extremely fast.
  See also [5.2]
  The future of AutoLISP already is Visual Lisp. For VLISP see [5.3]
  URL's: http://www.autodesk.com/vlisp, 
  http://www.autodesk.com/develop/devres/visual/faq.htm, also [0.1] below.

  [0.1] What changed with AutoCAD 2000?

  The name :) No, there's much more, but you may call it Release 2000, R15
  (though 15 is the version number and not the release number),  A2000 or
  abbrevated A2K.
  The new Visual Lisp kernel (formerly "Vital Lisp") replaced the old 
  xlisp-based AutoLISP kernel.

  What problems should you expect with Visual Lisp in R2000? (only the bad
  news). At http://xarch.tu-graz.ac.at/autocad/docs/r2000-news.txt
  I compiled a white paper. The major points are:
  Stricter error checking on loading, ACAD.LSP vs ACADDOC.LSP,
  You cannot/need not compile to ARX anymore, Incompatibilities
  AutoLISP - Visual LISP: Lisp functions are atoms no lists anymore,
  Protected symbols,
  Better exception handling, Pathname of the loaded VLX?,
  vl-export-symbol -> vl-doc-set, long acad symbol table names: EXTNAMES
  ActiveX automation, Variants and SAFEARRAYs, FAS4 cannot be loaded on R14.

  [0.2] Why cannot I create ARX anymore?

  With AutoCAD 2000 you cannot do that anymore as with ViLL or VLISP 4.
  Instead you compile to VLX (Visual Lisp Extension), which has basically
  the same functionality as the old Visual Lisp/Vital Lisp ARX, with the
  following differences:

* You'll have to (load) the app. Before you had to (arxload) it.
- Pro: Initialization is easier. The VLX doesn't abort completely on any
  error while loading. Before the whole ARX crashed with mysterious
  errors.
- Pro: VLX are much smaller because they don't carry the whole Lisp
  environment, the VLRTS, along. Instead there's only one environment,
  VL.ARX, distributed with acad itself. So you can ship much smaller
  applications.
- Contra: With loaded VLX there's no easy way to get the pathname of the
  app. Before it was possible with (arx) or (vl-exe-filename)

* VLX has the option of seperate or common namespaces. With seperate
  ARX you had only the option of seperate namespaces (in fact completely
  seperate lisp environments).
- Pro: This means that you can now choose the fastest and most secure
  compilation mode (LINK, DROP) and still keep common namespaces. (most of
  my apps benefit from this. I seperated my apps into one main module and
  several smaller ones)
- Pro: ARX is only compatible per release, thus completely incompatible!
  VLX is new and therefore compatible only to newer releases (R16,...) but
  as lisp application it is by far more compatible than a ARX app.

* Loaded ARX apps with (arx) return the pathname, loaded VLX apps with
  (vl-list-loaded-vlx) only a symbol, no path. This is a design flaw.

  You don't need ARX modules anymore. This is a feature, no bug.

------------------------------

Subject: [1] Where can I find AutoLISP routines on the Internet?

  The big AutoCAD tools sites with LISPs are:

  "AutoCAD Plugin Store" by beyond.com
     http://www.cadplugins.com/
     This is the by AutoDESK "officially recommended" tools site.
  "CADalog" - The AutoCAD Shareware Clearinghouse (Mike Clark)
    http://www.cadalog.com/
  "The CAD Depot", formerly known as "cadsyst" or "Rolling Stock Software",
    (David Whynot) recently bought by TenLinks.com 
    http://www.caddepot.com/

  They are specialized in AutoCAD related software and have a very
  good AutoLISP collection. Other professional AutoLISP shareware
  sites post their URL's to the newsgroup too. 

  Other relevant sites are:
  TenLinks (www.tenlinks.com) and the UpFront (www.upfrontezine.com) ezine
  are the best CAD news services. Autodesk also started their portal site 
  "Point A" at http://www.autodesk.com/pointa

  Some more sites with AutoLISP collections are:

  The CAD Users Webring
    http://nav.webring.org/hub?ring=caduser&list
  xarch AutoCAD Info & Tools (Reini Urban)
    http://xarch.tu-graz.ac.at/autocad/    (with search)
  CADalyst magazine code (compiled by "Hot Tip Harry" Art Liddle)
    http://www.cadonline.com/code/   (with search)
  Owen Wengerd
    http://www.manusoft.com/
  Terry Dotson
    http://www.dotsoft.com/
+ AcadX
+   http://www.acadx.com/
+ Paul Turvill
+   http://www.turvill.com/t2/
  Vladimir Nesterovsky
|   http://vnestr.tripod.com/
  Theo L.A. Groenenberg
    http://members.xoom.com/acadvice/autolisp.htm
  The CADshack (Jeff Foster)
|   http://www.cadshack.com/
  Lisp Factory (Jay Garnett)
    http://www.enteract.com/~jgarnett/
  Rakesh Rao - AutoCAD Tech Center
    http://www.4d-technologies.com/techcenter

  Older or broken links:
  AutoCAD Tech Journal code (Peter Sheerin)
    http://www.atj.com/ (old)
  CADENCE magazine code (Peter Sheerin)
|   http://www.cadence-mag.com/ (fixed)
  UCCB AutoCAD and AutoLISP page (Paul Standing)
    http://ucad1.uccb.ns.ca/acad/cad.htm (broken)
  McNeel's old lisp archive 
|   ftp://ftp.mcneel.com/pub/lisp/ (fixed)
  Dr.Lisp Utilities (Alexander Medwedew)
    http://idt.net/~compvent/ (fixed)
  SimTel - Coast To Coast - Archive (fixed, really very old stuff)
|   http://www.simtel.net/pub/msdos/autocad.html

| At http://support.autodesk.com/ (moved) were documents from the 
  Autodesk Product Support answering technical questions. (Their FAQ's)
+ The ASA (Support Assistance, some kind of FAQ) was once at 
+ http://www.autodesk.com/support/autocad/asa2000.htm, an improved but 
+ slow tool is now at http://support.autodesk.com/KnowledgeBase.asp.

[1.1] Are the comp.cad.autocad articles stored somewhere?

  There is no comp.cad.autocad archive or such a thing, but there
  are some search machines which store news articles. In
  particular:

| * http://groups.google.com/       - The biggest news archive
|     formerly known as http://deja.com/usenet
  * http://www.altavista.com/
      http://www.altavista.com/cgi-bin/query?pg=aq&what=news
  * http://www.excite.com/
      http://www.excite.com/search.gw?collection=news
  * Phoaks - People Helping One Another Know Stuff - Automatic Links Extractor
      http://www.phoaks.com/phoaks2/newsgroups/comp/cad/autocad/index.html

  The Autodesk discussion forums have also a search feature at
| http://discussion.autodesk.com

  Some specific older news postings are also stored at
  http://xarch.tu-graz.ac.at/autocad/news/contents.html

[1.2] Autodesk's SDK

  Up to Release 12 a Software Development Kit was available directly
  at Autodesk. The SDK1-2 was shipped with the international R12 for
  free. It included a lot of ADS and AutoLISP source code and libraries.

  From R13 on Autodesk provides a special developers network, comparable
  to Microsoft's, the ADN. The CD's are comparable to the old SDK but
  are more targeted to ObjectARX developers.
  Contact your nearest Autodesk headquarter for becoming a member.

  Some LISPs are at http://xarch.tu-graz.ac.at/autocad/code/adesk/SDK2

  In the US, ADN membership costs $600.00 per year.  The CDs don't include
  any SDK per se, but most of the stuff in the original SDKs is included
  in one form or another. (Owen)

------------------------------

Subject: [2] What are the best books to learn AutoLISP?

  AutoLISP to Visual LISP
    Kevin Standiford, Autodesk Press, ISBN 0-7668-1517
  AutoLISP: Programming for Productivity,
    William Kramer, Autodesk Press, ISBN 0-8273-5832-6
  Essential AutoLISP,
    Roy Harkow, Springer-Verlag, ISBN 0-387-94571-7
  AutoLISP in Plain English, A Practical Guide for Non-Programmers,
    George O. Head, Ventana Press, ISBN 1-566-04140-6
  AutoLISP Reference Manual
    Autodesk Press.
    Up to R12 there was a separate AutoLISP Reference book. Then AutoLISP
    became a part of the Customization Guide for R13. From R14 on this
    guide is compiled as Winhelp.
  Maximizing AutoLISP
    Rusty Gesner, Tony and Mark Middlebrook, Tony Tanzillo.
    A new Maximizing AutoLISP R13/R14 will be published hopefully
    sooner or later. But the R12 book is still worth buying, though it's
    difficult to find. More at http://www.group-a.com/~rusty

  There is a lot more AutoLISP books around.
  Recommended general LISP books (not AutoLISP!) are:
  ANSI Common Lisp, (Common Lisp primer)
    Paul Graham, Prentice Hall, ISBN 0-13-370875-6
  Structure and Interpretation of Computer Programs, (high-level Scheme)
    H.Abelson, GJ. Sussman, J. Sussman, MIT Press, ISBN 0-262-01153-0
    "This undoubtedly one of the best general computer books ever written."
  LISP, 3rd Edition,
    Patrick Henry Winston and Berthold Klaus Paul Horn,
    Addison-Wesley Publishing Company, ISBN 0-201-08319-1
  Looking at LISP,
    Tony Hasemer, Addison-Wesley Publishing Company, ISBN 0-201-12080-1


[2.1] Online AutoLISP documents, Winhelp [deleted]

[2.2] AutoLISP Coding Style

  Most of the samples being published by magazines or at various
  websites are written badly making the AutoLISP learning process even
  harder for newbies. LISP is hard to read anyway because of it's
  briefness and countless parentheses. Everybody is enforced to
  write clear, readable code. Autodesk's samples are quite well written
  but sometimes overdone. :)

  Automatic pretty printers, or so called beautifiers (see
  [6.3]) automatically format the code according to some kind of standard.

  On the R12 CD-ROM in the SDK2 ACG.DOC or at
  http://xarch.tu-graz.ac.at/autocad/docs/acg.txt is an excellent
  Autodesk documentation about coding, commenting and intentation standards
  to keep lisp code readable.

  The most important points are:
  * Comment your code using ";;;" at row 1, ";;" inside the code
    (indented) and ";" for trailing comments (at row 39)
  * Follow the indenting standards as given by the pretty printers
    to be able to write better structured code, which is more readable.
      esp. for SETQ, DEFUN, IF, COND, PROGN
  * Try to avoid global variables. If you use them (for efficiency), to
    clarify, place asterics around them in uppercase, i.e: *GLOBAL*
  * Don't forget to localize your variables (behind "/" in the DEFUN
    parameter list). Only for debugging purposes you may want to
    undefine them temporarly.
  * Name protection: Since AutoLISP provides no protected name space,
    it's easy to overwrite even system functions. Use unique
    short prefixes at least when you publish or give away your code.
    I use UR- for functions and UR: for variables. The ADGE and Autodesk
    forces even 4 letter prefixes. Then your names are safe
    from being overwritten by other kamikaze functions.
  * Always use the leading underscore with any string (commands and
    options) given to COMMAND and OSNAP. There are even enough
    commercial programs which do not work on international versions.
    (command "_PEDIT" ss "_J") is better than (command "PEDIT" ss "J")
  * Don't do too much SETQ's: LISP was originally a functional language,
    without any variables. There are enough constructs which work
    efficiently with lists without the need of storing values
    intermediatly in symbols. (see code samples [22]...)
    But for readability and debugging purposes you should always set
    symbols.
  * An old LISP rule is: Any good function is not longer than 6 lines :)
    (LISP is the second oldest computer language, invented by John
    McCarthy at the MIT in 1958)
  * Prefer CONS over APPEND: three CONS and one REVERSE is better than
    one APPEND. For tricks with APPEND (omitting NIL) see esp. Serge's
    samples: i.e. REMOVE at [11] or the style comparison at [23.1])
  * Try to use English symbols and comments
  * Don't use T, MIN, MAX or LAST as symbols! These are system functions!

------------------------------

Subject: [3] How do I debug AutoLISP programs?

[3.1] There are some native AutoLISP debuggers:

  * Visual Lisp by Autodesk and Vital Lisp Professional support
    it in the IDE (the best),
  * ACOMP for R10 had one, (free)
     you can still use it with R12 DOS, but then you've got only the R10
     LISP functions, i.e. no WCMATCH function,
  * Ld, AutoLISP Debugger for R14, R13c4 and R12/DOS from CZ,
    (free) at http://www.cadstudio.cz/ftp.htm

  See "[5] AutoLISP compilers"

[3.2] Modular style, TRACE

  The best support you can have for debugging is write your
  code in a well designed, modular style, pulling out distinct
  tasks into separate functions and then liberally using
  nested function calls. This will allow you to use the
  TRACE function as needed to locate any errors.

[3.3] You may include BREAK functions and debug-print into your source
  code.

  Examples:

  ;;; Debugging functions
  (defun break (s)
    (if *BREAK*
      (progn
        (princ "BREAK>> (stop with <Enter>)\nBREAK>> ")(princ s)
        (while (/= (setq s (getstring "\nBREAK>> ")) "")
          (print (eval (read s)))))))
  (defun dbg-print (s)  ;accepts atoms and lists
    (if *DEBUG*
      (if (listp s)
        (MAPCAR 'print s)
        (print s))))
  (defun C:DEBUG () (setq *DEBUG* (not *DEBUG*)))  ;switch it on and off
  (defun C:BREAK () (setq *BREAK* (not *BREAK*)))
  (defun CONT () (setq *BREAK* nil))    ;cont. without any interruption

  For a usage example see:
    http://xarch.tu-graz.ac.at/autocad/news/break_ex.lsp

------------------------------

Subject: [4] How can I protect my AutoLISP programs?

  "You really have to protect it? If you just want to share routines
  with friends, why not give them the code? Working with others
  can be a great way to get new ideas and lead to a better
  application. Some of the best utilities were improved by my friends
  or I have improved some of my friends utilities." (Dennis)

[4.1] Kelvinate
    with KELV.EXE (on the R12 CD-ROM or at the AutoLISP sites "[1]").
    Free. De-Kelvinate LISP's with any pretty printer, see [6.3].
    Symbol names (functions and variables) will stay garbled and comments
    are lost.
[4.2] Protect
    with PROTECT.EXE (on the R12 CD-ROM or at the AutoLISP sites "[1]")
    Note that unprotectors exist. Free.
[4.3] Kelvinate and Protect
    First kelvinate, to make it unreadable, then protect. Free.
[4.4] Convert
    Shareware LISP En-/Decryptor by Maciej Lukasiewicz, Sweden.
    With Convert encrypted "Protected Lisps" cannot be decrypted by other
    programs, but by Convert it can.
[4.5] ACOMP
    AutoLISP compiler ACOMP.EXE, on the R12 international release or
    at the AutoLISP sites. Free. More docs about ACOMP are at
    http://xarch.tu-graz.ac.at/autocad/bi4/  See also [5.1]
[4.6] Vital LISP Professional
    Formerly at http://www.basissoftware.com/vill.htm [broken]
    Say "ViLL". Outdated. See also [5.2]
[4.7] Lisp2C
    LISP to C converter, for R12/R13/R14 Dos/Win (Watcom, Metaware,
    MSVC Libs). You need to own such a C/C++ compiler. Quite expensive.
    http://www.basic.si
[4.8] Visual Lisp by Autodesk
   say "VLISP". see [5.3]


  FAS Security:
    There was recently a lengthy discussion about FAS security at both
    newsgroups. Apparently FAS can be decompiled to readable source code,
    but this tool is not available on the net yet. Rumors say that MNC
    files can also be decompiled for years now but this doesn't exist the
    net either.
    Linked and dropped FAS/VLX (compiled with Optimized/Internal) is
    similar to Kelvination.
    Symbol names, strings and numbers are more insecure than algorithms.
  Summary:
    Serious encryption is only done with Vital LISP and its successors.
    Kelvinating makes LISP files unreadable and load faster.
    Protected lisp files can be easily decrypted. With
    Convert -e$GUARD encrypted LISPs can be unprotected only with Convert.

------------------------------

Subject: [5] AutoLISP compilers

  There are three AutoLISP compilers, better ones could maybe used in the
  future. Some Lisp and Scheme platforms already do or will support ActiveX
  or just a simple FFI.

[5.1] ACOMP
    ACOMP was supported up to R12 for the international releases only.
    It is free, and doesn't work with R13 nor with domestic R12/Win.
    It produces .BI4 files and needs special ACADL.EXP supplied as
    ACADLC.EXP     See http://xarch.tu-graz.ac.at/autocad/bi4/
[5.2] Vital LISP Professional
    by Basis Software Inc. USA.
    Basis doesn't continue developing Vital Lisp anymore.
    License-free runtime modules for R12/R13/R14 DOS/Windows/NT
      See http://www.basissoftware.com/vill.htm
    Some dealers still have it on stock. The latest version was 3.2. The
    R14 version (ViLL 3.x) includes ActiveX (like VB) and reactor
    support. See also [6.1] and [4.6]
[5.3] Visual Lisp by Autodesk
    VLISP 4 (for R14), the successor of Vital Lisp, is basically the same
    as ViLL 3.2, only the GUI, some function names and the docs changed:
      vill- => vlisp-, the vlx- => vl- prefixes.
      Some vlax- funcs have more hyphens.
    With AutoCAD 2000 VLISP replaced the old AutoLISP engine. See [0.1]
    VLX files are packaged FAS files with optional DCL resources, used
    by R14/R15.
    AutoCAD 2000 FAS/VLX are incompatible with previous releases
    (FAS2 -> FAS4) because of added language features (seperate namespaces)
[5.4] Better ones: Common Lisp and Scheme
    Native ARX exists for Corman Common Lisp (a simple console),
    COM support for Allegro Common Lisp 5, Lisp Works for Windows and in
    the future for GambitC.
    Via a FFI ("Foreign Function Interface") almost every lisp or scheme
    can communicate with AutoCAD.
    See http://xarch.tu-graz.ac.at/autocad/lisp/ffis.html
    Little work is done with Corman Lisp and ACL5, one commercial product
    uses ACL5 ("Design++" by Design Power http://www.dp.com/)
    See http://xarch.tu-graz.ac.at/autocad/bi4/ for more.

  Summary:
    AutoLISP compilers are bytecode compilers needing a runtime system.
    AutoCAD 2000 uses VLISP now, so the runtime system is included.
    You cannot create standalone programs, though ViLL/Vlisp (<=R14)
    creates a stand-alone ARX. The symbols are encrypted.

------------------------------

Subject: [6] AutoLISP editors and other tools

[6.1] AutoLISP editors
  Visual Lisp by Autodesk
    see [5.3]. The best and most recommended tool. With AutoCAD 2000 it
    is included for free.
  Emacs for NT
    Huge editor and quite hard to learn but it's written and
    customizable in LISP. Free, for all platforms. Comes in two flavors,
    www.xemacs.org or the GNU emacs for NT.
    Check out http://xarch.tu-graz.ac.at/autocad/lsp_tools/ntemacs.html
  Vital LISP 
    outdated by Visual Lisp. Not available anymore
  LispLink 2000
    Commercial AutoLISP Editor with Syntax Highlight, Parenthesis 
    Checking, Project Manager, Dialog Preview, and Support for Visual 
    LISP Functions and FAS Compilation. http://www.caelink.com/
  CodeMagic
    Shareware text editor with AutoLISP syntax highlighting.

Old stuff:
  LispPad
    AutoLISP Editor by Tony Tanzillo.
  Visual LISP by WSSW
    Old small Windows LISP Editor, Version 1.0 was even free. See [1]
  WCEDIT 2.02
    Old ADS editor for DOS R12, can evaluate lisp code from within the
    editor, free.  See [1]
  CODEKEY
    Old commercial DOS IDE, internal pretty printer, protect, unprotect,
    kelvinator. Still available?
  ALLY 3.0 and CADET
    Shareware LISP Analyzer and Editor. See [6.2]
  pred
    free, small dos editor which provides parenthesis highlighting.
    At ftp://xarch.tu-graz.ac.at/pub/autocad/lsp_tools/pred.zip
    A similar editor is ADE.
  LSPEDIT from xlisp-stat
    A simple free Windows Lisp editor that supports parenthesis matching and
    code indentation.
    Check out http://www.stat.umn.edu/~luke/xls/xlsinfo/xlsinfo.html

  General customizable programming editors like MultiEdit Pro,
    WinEdit, E!, PFE, TextPad, UltraEdit or PFE are widely used also.
    They usually don't provide Lisp syntax checking or pretty printing,
    but (some even regular expression) multi-file search/replace and
    customizable syntax highlighting.

  There are others not that good (ADE) nor I don't have a description
  yet.

[6.2] Analyzers, Packagers and Parenthesis checkers
  Parenthesis checkers should not be used anymore. Editors should do the
  job. Analyzers generate a function cross-reference, the calling and the
  reverse callers tree. Packagers are used to generate libraries from
  various source files, copying all the needed functions.
  There's currently no code-walker which can internationalize command
  strings, but with R15 came a lisp analyzer (LCA).

  VLISP's [5.3] compiler analyses (compile with full messages) and
    checks parens <Ctrl-Alt-C>
  Reini's AutoLISP Packager
    http://xarch.tu-graz.ac.at/autocad/lsp_tools/#Packager
    Browsable function cross-referencer, reverse calling tree, creates a
    library from source files. ("Packaging" or "Function Shaker")
  PEI Findvars
    Similar to the Packager above, but not only functions, additionally
    detects symbols to be localized. http://www.perceptual-eng.com
    I personally use this.
  RapidLisp v1.0c [new]
    Shareware Lisp analyser für R14. http://www.cps.de/cad/rapidlisp/
  AVC - AutoLISP Variable Collector [new]
    Freeware, finds all variables to be declared per function.
    http://users.actcom.co.il/sysoft/vc.htm
  LCA - Autodesk's AutoLISP Compatibility Analyzer
    On the Migration CD. Details AutoCAD 2000 compatibility issues found 
    in specified AutoLISP (LSP) or Menu LISP (MNL) files. (simple "Code Walker")

  ALLY30.ZIP (old)
    Shareware LISP analyser. Checks syntax and prints statistics, function
    dependence tree and used symbols, but no packaging. At [1]
  lck21b.zip (old)
    LCK LISP Checker 2.1b (graphical)
  paran.zip  (old)
    Simple
  PARNCH.ZIP (old)
    Simple
  There are also some AutoLISP programs which count parenthesis.

[6.3] Pretty Printers
  External:
    FMT202S.ZIP
      LISP, DCL and FRM source code formatter. Not checked yet.
    LB.EXE
      Autodesk's source code beautifier.
      In the SDK2 or at [1]. Has problems with longer strings,
      and new-style in-line comments.
    PPRINT.LSP
      In the SDK2, see [1.2], or at [1]
  Internal:
    Visual Lisp, Vital LISP, Emacs and Codekey provide internal
    beautifiers as I'm aware of it.

------------------------------

Subject: [7] AutoLISP problems and bugs

  For AutoCAD 2000 and unexperienced VLISP users see [0.1].
  There are almost no known serious AutoLISP bugs. The language
  interpreter itself (ACADL.EXE/.EXP, VLISP) works undoubtedly well.
  Some restrictions are based on the AutoCAD, ActiveX or the Proteus
  (DCL) engine. Some support LISP programs (i.e. DDMODIFY.LSP) are
  faulty sometimes.
  For Visual Lisp see the README.txt which lists all known bugs and
  limitations. Crashes with reactors are ACAD bugs.

  Two inofficial buglists are at:
  http://www.cadonline.com/exclusive/bugs/bugwatchlist.htm (the big one)
  http://www.dotsoft.com/buglist.htm (a private and short one)

  * LDATA  by Tom Berger     (VLISP for R14 and A2000)
    In short: Don't use LDATA at all. It may destroy DXF and DWG's 
    in A2000. It is also VERY hard to get rid of them.

  * List Arguments with DOTTED PAIRS Passed from AutoLISP to
    Visual LISP or back may loose the outer parens.
    See the Visual Lisp README (undocumented in Vital Lisp)

  * SINGLE ATOM LISTS returned incorrectly from EXTERNAL APPS
    Visual LISP can not distinguish between a LIST of a single
    atom (element), and a single atom returned from an external
    ObjectARX or ADS application.

  * ENTGET used with LWPOLYLINE, HATCH  (R14 only)
    The Z coordinate (caddr (getval 10 ele)) is a random number and
    often causes a floating point exception because it may too low or
    too high. Workaround: see part 2, Subject [23.1]

  * ENTMAKE VERTEX  by Terry Dotson     (R14 only)
    A problem can occur during the process of using (entmake) to create
    polylines, you must assign the layer to each of the VERTEX 
    definitions (which Autodesk has told us), but you must also assign 
    the layer to the ending SEQEND. Absence of this will cause the SEQEND 
    to end up on the current layer, which can be later frozen. Attempts to
    move this piece of geometry will then cause a EREGEN error and crash 
    in R14 (only).

  * ACAD_STRLSORT: Strange sort order in Windows.
    The chars in Windows are not sorted on its ASCII representation!

      Windows: (acad_strlsort '("-1" "+1")) -> ("-1" "+1"),
      DOS:     (acad_strlsort '("-1" "+1")) -> ("+1" "-1")
      Both:    (mapcar 'ascii  ("-" "+"))   -> (45 43)
    More at http://xarch.tu-graz.ac.at/autocad/docs/strlsort-bug.html

  * AI_PROPCHK
    (ai_propchk) was renamed to (C:AI_PROP) in the R13c3 update
    patch. "The AutoLISP function ai_propchk has been changed to c:ai_prop
    so that it behaves similarly to other commands. This allows pressing
    return to bring back DDMODIFY if selected from the toolbar."

  * Faulty action callbacks in R13 DCL code crash AutoCAD
    There is a bug in R13 where AutoCAD crashes with a Fatal Error if
    an error occurs in AutoLISP code during an action callback from a
    scroll bar in a dialog box.  For instance, if you try to evaluate a
    null function during the callback, AutoCAD crashes instantly.
    Technically, this isn't a bug in the AutoLISP interpreter, but we
    would still call it an AutoLISP bug.

  * You cannot rely on bitvalue 64 in flag 70 in symbol tables anymore
    since R13, but in all previous releases. Inserted blocks may have 
    64 not set.

  What else? See the unofficial AutoCAD buglist compiled by Steve
  Johnson for more faulty AutoLISP programs and behaviours, at
  http://www.cadonline.com/exclusive/bugs/bugwatchlist.htm

  * Protected LISP Files
    In pre-c4a R13 protected LISP files didn't stay protected in
    memory. In our opinion, this problem needs to be made known to all, so
    developers don't inadvertently assume their protected code is
    safe from prying eyes. This FAQ topic caused a major problem in
    moderated CompuServe's AutoCAD Forum.

  * Limited number of open selection sets
    They are intermediatly stored in temporary files. Get rid of not
    needed selection sets with setting the symbols to nil and run (gc),
    the garbage collector, which actually closes those files then.
    The maximal number depends on the operating system, i.e. in DOS
    of the FILES= value in CONFIG.SYS. R13 improved the number.

  * Numbers: range, accuracy, numerical precision
    Integer numbers are internal long fixnums (signed, 32-bit), but the
    communication from AutoLISP to AutoCAD accepts only 16-bit short
    fixnums, in the range -32768 .. +32767, because AutoCAD needs only
    short fixnums.
    Floating point numbers are doubles (64-bit IEEE). All internal
    AutoLISP and AutoCAD numerical calculations work with this double
    format, which should be sufficient. At least the first 14 decimal
    places are exact.
    A common problem is the confusion betwen the actual number (exact)
    and the rounded string representation. The number which is shown on
    the command-line is always the rounded string which takes care of
    LUPREC and DIMZIN.
    However with geometric comparisons there often occur round off errors,
    so that it's wise to compare points with a small fuzz factor 
    [1e-12..1e-6].
      (equal pt1 pt2 1e-6)      ; 0.000001 rounding error tolerance
    instead of (equal pt1 pt2), esp. with angles.
    See also http://www.autodesk.com/support/techdocs/td30/td301207.htm

    VB: It was also reported lately, that with certain automation
    controllers loaded, numerical accuracy and locale issues (`,´ vs `.´)
    had undesirable sideeffects. A solution and explanation of this 
    problem is pending. (Mostly in `,´ as decimal delimiter countries 
    such as Germany)

  * ACOMP's (EQ) strictness
    With [5.1] ACOMP's compiled code you have to take care that the
    (EQ) behaviour in BI4's is much stricter than in plain AutoLISP. In
    AutoLISP (eq "1" "1") is T where in ACOMP's compiled code it's nil.

  The following are not real bugs, that make AutoLISP crash or return
  false results. They are just bad language implementations.

  * AND and OR should return the value of the not-NIL argument
    instead of T. See http://xarch.tu-graz.ac.at/autocad/docs/and-bug.html
  * MAX and MIN should handle string types too, because < and >
    accept and process strings types too.
  * see ACAD_STRLSORT above.
  * for stack overflow errors see [14]

------------------------------

Subject: [8] Sorting with AutoLISP

  In short: use VL-SORT (generic) or ACAD_STRLSORT (strings only),
  but beware: VL-SORT removes duplicate entries (which are EQ)!
  
  I've set up a AutoLISP sort overview at
    http://xarch.tu-graz.ac.at/autocad/lisp/#sort
  In LISP the mostly used sort method is merge sort (also used in
  (str-sort) in AutoDesk's TABLES.LSP sample) because that's a natural
  method for linked lists. Normally (e.g. in C) you use heap sort (for 
  any data) or qsort (for random data) and insertion sort for the small
  lists (< 7) or sublists within the algorithm.

  There is a LISP code for shell-sort, bubble-sort, insertion-sort,
  quick-sort available for any data, lists of lists and indeces to
  lists. In LISP you can pass the predicate function to sort which is
  evaluated at run-time (here called 'method'). That's why you need
  only one sort function for multiple data types (i.e. numbers,
  points on x or y, strings, ...)

  (sort data method)    ;method: less-than-predicate
                        ;default for numbers: '<

  Some sample timings from
  http://xarch.tu-graz.ac.at/autocad/lisp/sort/ur_sort.lsp
  sorting 100 elements:
    bubble sort   : 13.639008 sec/ 30.08%
    insertion sort: 13.368042 sec/ 29.48%  (fast for sorted lists)
    shell sort    : 13.478973 sec/ 29.73%  (poor implementation)
    merge sort    :  2.232971 sec/  4.92%
    quick sort    :  2.433960 sec/  5.37%
    vl-sort       :  0.099976 sec/  0.22%  (Visual/Vital LISP internal)
    acad_strlsort :  0.089996 sec/  0.20%  (AutoLISP internal, strings)

------------------------------

Subject: [9] Recursion

  This is not an often asked question but a very interesting one,
  because LISP itself is defined recursively and it's often the
  easiest way to articulate hard problems.

  There some fine documents about recursion at
  http://xarch.tu-graz.ac.at/autocad/lisp/ especially the
  http://xarch.tu-graz.ac.at/autocad/lisp/recursive.html tutorial by
  Dennis Shinn.

  It explains in great detail:

  (defun fact (n)
    (cond
      ((zerop n) 1)
      (T (* n (fact (1- n))))))

  Note: There's also a self-modifying example of this function
  explained at http://xarch.tu-graz.ac.at/autocad/lisp/self-mod.lsp

------------------------------

Subject: [10] Iteration with MAPCAR,...

  Same as with recursion this is not a often asked question, but it's
  quite hard to understand too.
  Iterative statements in AutoLISP are: WHILE, REPEAT, FOREACH and
  MAPCAR. We use them widely in this FAQ code because they allow
  brief code.

  There's a short course in LAMBDA, QUOTE, MAPCAR... by Vladimir
  Nesterowsky:

  >>         "There are 14 paths and 12 pigs.
  >>         How can there be 24 ducks?"
  >> Is there a lisp command that will allow me to pick these
  >> lines of text, and recognize the number(s) in each line,
  >> in order to, say, raise each number by two?
  >> Leaving the sentence structure, etc, intact?
  This is one way. (I am sure there are many other ways)

  (defun mult2 (strng)          ; by Vladimir Nesterowsky
    (strlgather
      (mapcar
       '(lambda (s / n)
          (if (zerop (setq n (atof s)))
            s
            (rtos (* n 2))))
        (strlparse strng " "))  ; parse by spaces
      " "))                     ; gather back with spaces

 is explained at http://members.tripod.com/~vnestr/mapcar.txt

  ;;; flip rows and columns in a matrix
  (defun transpose(l)           ; by Doug Wilson
    (apply 'mapcar (cons 'list l)))

is explained at http://xarch.tu-graz.ac.at/autocad/lisp/transpose.002.html

------------------------------

Subject: [11] S::STARTUP, My LISPs aren't loaded at startup anymore

  LISP files can be loaded at the startup using LOAD in ACAD.LSP.
  Some LISPs, required with a menu to work, should be loaded from
  the corresponding <menu>.MNL file. The <menu>.MNL file - if different -
  should load ACAD.MNL

  LISP functions calling commands at the startup should be defined in
  S::STARTUP of ACAD.LSP. This function is called at the startup
  after the initialization automatically. Otherwise you'll get the
  "Command list interruption (6 . 2)" errors.
  Note: (command) may be safely called from within MNL files. 
  (S::STARTUP) is mainly used to check for partial menus now.

  If the file name was provided without an extension the LOAD function
  assumes .LSP. If - without a path prefix, the usual AutoCAD library path
  is used, which is
    1) The current directory
    2) The directory containing the current drawing file
    3) The directories defined in the ACAD environment variable
       (setup in the Preferences box, SUPPORT paths)
    4) The acad.exe directory
  If your program isn't loaded anymore automatically, check your AutoCAD
  library path settings.

  With ACADLC (of ACOMP) and the domestic release of AutoCAD R12 ACAD.LSP
  is not loaded automatically. Therefore you must append (load "ACAD" -1)
  to your ACAD.MNL.

  Sample ACAD.LSP:
  ;;;ACAD.LSP
  ;;; Fred the Beaver, 12/12/94
  (load "init" -1)                ; this loads some tools of mine
  (defun S::STARTUP ()
    (load "new-end" -1)           ; this redefines the END command
  )

  The -1 argument provides LOAD from interrupting the startup process, if
  any LOAD failure (causing an AutoLISP error). If a failure at the
  load-time occurs, -1 is returned, but the evaluation does not stop.
  -1 can be any expression as well.

  Sample code to enhance S::STARTUP in your code. With Visual LISP
  compiled code this will not work, it must be defined with DEFUN-Q
  instead. Functions are generally no lists anymore! Better than to
  use DEFUN-Q for S::STARTUP is to check for known hooks, a list of
  user-defined functions which are inserted and evaluated at run-time.

  (defun MY::STARTUP ()         ;your startup code goes here
    ;..
    (princ))

  (setq S::STARTUP
    (if (and S::STARTUP (listp S::STARTUP))     ;already defined in
                                                ; ACAD.LSP or elsewhere
      (append S::STARTUP (cdr MY::STARTUP))     ;append your code
      MY:STARTUP))                              ;just your code

  or a simple one:

  (if (and S::STARTUP (listp S::STARTUP))       ;usually called consp
     (setq S::STARTUP (append S::STARTUP (list func '(princ))))
     (setq S::STARTUP (list nil func '(princ))))

+ Vladimir Nesterovsky:
  The main difference now in A2K+ versions is that functions defined 
  with DEFUN are now a new datatype, USUBRs, and not lists as before. 
  But when the function is defined with DEFUN-Q, it is a list still, 
  like in previous versions. 

  Here's the utility function to use that works in both cases: 

  (defun plug-into-startup (funcname) ;by VladimirNesterovsky
    "to be called with quoted function name"
    (eval (list
      'defun 's::startup ()
      (if s::startup (list (list 'quote s::startup)))
      (list funcname))))

  So if you have all your startup code packed into one routine 

  (defun my-startup ()
    (alert "My Startup"))

  You make it work with the call 

  (plug-into-startup 'my-startup)

  Inside your code that is executed on startup, e.g. acaddoc.lsp 
  or whatever.

  See also  "[12] How to Autoload my programs?"

------------------------------

Subject: [12] How to Autoload my programs?

  How to load my programs automatically? You can either load your
  whole program at startup (see  "[11] My LISP doesn't
  load at startup anymore") which needs more time and memory at
  startup time, or you can define them via the autoloading mechanism.
  From R14 on ARX programs use a new autoloading scheme (called
  "demand loading") with some registry settings and not from ACADRxx.LSP
  anymore.

  Look at the end of your ACADRxx.LSP how AutoCAD autoloads its programs.

  ;;;===== AutoLoad LISP Applications =====
  ...
  (autoload "dline" '("dline" "dl"))
  ...

  This defines the commands DLINE and DL in the list to be loaded
  from the file DLINE.LSP when the user first calls the command DLINE
  or DL. Before that the function is simply defined like this one:

  (defun C:DL () (load "DLINE")(C:DL))

  In fact the definition is more complicated because of error
  handling.
  After the first call the function is overwritten with the
  definition in the program.

  Advantages of autoloading:
  * Startup is faster, because you dont have to load all your lisp
    files. You just define the simple *wrapper* definition as above.
    This is done by the (autoload) function.
  * You need less memory.

  Disadvantages:
  * On errors in your program you will fall into a never ending
    loop, which will only stop after a stack overflow or Ctrl-C
    Note: with ACOMP compiled code even Ctrl-C is impossible.
      Insert then a call to an uncompiled (princ) somewhere.
  * You have to define and maintain all command names from your
    program in the autoloader definition. Changes to the lisp
    filename or the command name will cause the above error.

  Where to put your (autoload) definitions?

  * Not to ACADR13.LSP.
  * Well we recommend putting it to an initialization file of yours
    and not to ACAD.LSP because this is often changed by different
    applications and ACAD.LSP should be kept rather small.
      I.e. put it to a AUTOLOAD.LSP or INIT.LSP, which is loaded from
    ACAD.LSP. See "[11] My LISP doesn't load at startup anymore"
  * It should be mentioned that users should *not* modify ACADRxx.LSP.
    Since ACAD.LSP is not overwritten during upgrades, it is guaranteed
    to remain safe. In addition (as we saw with the R13c4a patch) if the
    ACADR13.LSP file has been  modified, then the patch process may
    refuse to update it, thus resulting in program malfunctions.

------------------------------

Subject: [13] How can I pass a variable number of arguments to a lisp
function?

  With plain AutoLISP this is not possible.
  You can either pass all your arguments in a list like this:

  ;;; print a variable number of arguments (of any type)
  (defun my-princ (x)
    ;; simple version, for better stuff look at the SDK2: PRINTF.LLB
    (if (listp x)
      (mapcar 'princ x)
      (princ x)))

  Or you have to define the function in ADS and export it to
  AutoLISP.
  Then you are free to write:
    (ads-print "Hello " "World " 1 2 3)
  or even
    (ads-printf "Hello %s %i %i" "World" 2 3)

  Look at Reini Urban's and Vladimir Nesterovsky's ADS samples at
  http://xarch.tu-graz.ac.at/autocad/ads for implementations of the
  above examples.

  Official wishes were pointed to Autodesk regarding &optional as
  AutoLISP language enhancement, but it was not implemented in R14.

------------------------------
Subject: [14] How can I avoid stack overflows?

  In old AutoLISP the stack size was hardcoded. It couldn't be extended,
  but its size should be sufficient for most purposes. In the Visual
  Lisp IDE the stack overflow is simulated at 984 recursions, on the 
  A2000 commandline or loaded programs outside the IDE there's no 
  overflow anymore. This is dangerous on recursion errors of yours,
  see [9]. Most stack overflow errors occur on a program error of
  yours, preventing the system from falling into an endless loop, or
  from using recursive functions on large lists. Therefore you are
  limited to quite short lists with recursive functions and old versions.

  You cannot decrease your used stack size with using less local
  parameters in your recursive function! However do not use APPLY, EVAL
  or MAPCAR to call your function recursively, because they eat up the
  stack. Using tail recursion doesn't help either.
  You have to convert your recursive function to a iterative one.
  (There is a mathematical theorem that says, that every recursive
  function can be converted to a iterative one, tail-recursive ones
  even automatically.) Iterative versions may use stack-like functions
  like (push) and (pop), but those versions store the stack on the heap
  (autolisp node space), which size is only limited by your amount of
  virtual memory available.

  You can test the stack overflow with this simple function:

  ;;; create a list of n numbers (zero based)
  (defun intlst (l n)
    (cond ((zerop n) l)
          (T (intlst (cons (1- n) l) (1- n)))))
  and try:
  (setq n 100)(while (intlst nil (setq n (+ 10 n)))(print n))

  In AutoLISP of R12/DOS you reach the stack limit with
  (intlst nil 138), in A13/Win with (intlst nil 240), in ACOMP bi4's
  with (intlst nil 1240), in Vital LISP/Visual Lisp IDE with 
  (intlst nil 984). With R10c10, the first dos extended lisp version, 
  you could enhance the lisp stack size with the environment variable 
  LISPSTACK. ACOMP for R10 had COMPSTACK.
  With Vital LISP or Visual LISP RTS or A2000 (outside the IDE) the 
  stack size is unlimited.

  Conversion to an iterative version yields the required results:

  (defun intlst (n / l)
    (repeat n
      (setq l (cons (setq n (1- n)) l)))) ;this looks ugly but it works

------------------------------

Subject: [15] (command "ROTATE3D") does not work! Why?

  Some commands are no internal AutoCAD commands, they are simple
  AutoLISP programs beginning with C: even if they are defined in ADS
  programs. Only native Rx applications (or now with vlax-add-cmd)
  export true commands.

  A list of all these commands are found in ACADRxx.LSP in the
  AUTOLOAD section.  (see also "[12]")
  All these commands have to be called with (C:ROTATE3D) instead of
  (command "ROTATE3D").
  However ADS functions may take optional arguments. See the
  customization manual for more.
  i.e. (c:rotate3d ss p1 p2 angle) is also valid, even (rotate3d ...)

------------------------------

Subject: [16] LISP programs operating over multiple drawings

  "I am having trouble getting a lisp file that will open a drawing and
  continue running. Once the new drawing is opened the LISP file ceases
  to exist in the Autocads memory. It has to be reloaded to recognise
  the commands."

  LISP memory is reloaded on a per drawing basis.  There are some
  ways to execute a LISP on multiple drawings:
  1) via a script that executes on multiple files.
     MYSCRIPT.SCR:
     (load "mylisp")
     _QSAVE _OPEN !nextdwg
     (load "mylisp")
     _QSAVE _OPEN !nextdwg
     ...
   2) External 3rd party software such as RunLisp, ScriptPro or DDSCRIPT automate
      step 1.
   3) R14 has a new feature, called 'Persistent LISP'.
      Set it in Preferences-Compatibility-Persistent LISP
   4) Vital LISP has a built-in variable to act as Persistent LISP:
      (setq *VILL-NEW-FULL-INIT* nil)   ;keep symbols between sessions
   5) same with Visual LISP: (setq *VLISP-NEW-FULL-INIT* nil)

------------------------------

Subject: [17] How to export Visual Lisp functions to AutoLISP/AutoCAD?

C: functions are automatically exported to AutoLISP. Plain vlisp/vill
lisp functions must be exported either with (vl-acad-defun funcname) or
their symbols may be exported with a special compiler pragma, defined
either in the LSP file or in the GLD (global declarations) file. Better
use special prefixes for such functions.

.GLD:
(AUTOEXPORT-to-ACAD-PREFIX
  ;| name prefixes for functions to be autoexported to AutoCAD: (strings) |;
  "myx-*"
  )
or one by one
.LSP:
(pragma '((export-to-acad myx-func1 myx-func2)))

Note: There may exist known bugs in vlisp and vill with lists of atomic
symbols and dotted pair lists in such functions arguments and return
values. See [7].

Functions exported by external apps which are used in your application
must be defined via XDF.

Symbols (variables) whose values are updated in Visual Lisp and which
values are also used in AutoLISP or AutoCAD (the menu e.g.), first may
be marked for the compiler to be external with:
  (pragma '((not-localize myx:symbol)))
but the value must be exported with
  (vlisp-export-symbol 'myx:symbol)
each time the value is changed in Visual Lisp and control is returned
to AutoCAD to be able to get the latest value in AutoLISP or in AutoCAD
with !myx:symbol

You may forget this whole chapter with AutoCAD 2000, however you might
need to export your function from the protected namespace then with
VL-DOC-SET.
See also http://www.autodesk.com/support/techdocs/td17/td175363.htm

------------------------------

Subject: [A] Disclaimer, Notes from the authors

  If you think of questions that are appropriate for this FAQ, or
  would like to improve an answer, please send email to Reini Urban
  <rurban@x-ray.at> but don't expect an reply.

  This AutoLISP FAQ is Copyright (c) 1996,97,98,99,2000 by Reini Urban.

  This FAQ may be freely redistributed in its entirety without
  modification provided that this copyright notice is not removed. It
  may not be sold for profit or incorporated in commercial documents
  (e.g. published for sale on CD-ROM, floppy disks, books, magazines,
  or other print form) without the prior written permission of the
  copyright holder. Permission is expressly granted for this document
  to be made available for file transfer from installations offering
  unrestricted anonymous file transfer on the Internet and esp. to be
  included into the official AutoCAD FAQ.

  The sample code is, if not otherwise stated, (c) 1996,97
  by Reini Urban and may be freely used, but not sold.
  The basic functions in [20] are, if not otherwise stated, (c) 1991-97
  by Reini Urban and may/should be freely used.

  If this FAQ is reproduced in offline media (e.g., CD-ROM, print
  form, etc.), a complimentary copy should be sent to Reini Urban,
  X-RAY, Nibelungeng. 3, 8010 Graz, Austria

  This article, the contents and the sample code, is provided AS IS
  without any expressed or implied warranty.

[A.1] FAQ Locations

  Homepage of the HTML'ified version:
    http://xarch.tu-graz.ac.at/autocad/news/faq/autolisp.html
+ Annotated AcadWiki version:
+   http://xarch.tu-graz.ac.at/acadwiki/AutoLispFaq
  The posted ascii versions (and always latest versions) are at
    http://xarch.tu-graz.ac.at/autocad/news/faq/autolisp.1 and
    http://xarch.tu-graz.ac.at/autocad/news/faq/autolisp.2
  The Winhelp version (zipped with faq and code) is at
    ftp://xarch.tu-graz.ac.at/pub/autocad/news/faq/autolisp.zip
  The FAQ usenet archive is at
    http://www.faqs.org/faqs/CAD/autolisp-faq/ resp.
    ftp://rtfm.mit.edu/pub/usenet-by-hierarchy/comp/cad/autocad/
  The LISP code from this FAQ is at
    ftp://xarch.tu-graz.ac.at/pub/autocad/news/faq/FAQ-CODE.LSP
  See also the cca glossary for common abbrevations at
    http://xarch.tu-graz.ac.at/autocad/news/faq/glossary.html
  Submissions for a new AutoCAD FAQ are stored at
    http://xarch.tu-graz.ac.at/autocad/news/faq/new-acad
  A french translation of the FAQ was made by Roger Rosec
    http://www.newz.net/acadplus/page5101.htm
  A japanese translation of the FAQ was made by MASAMI Chikahiro
    http://www.page.sannet.ne.jp/chestnutsburr/autolisp-j.html
  A russian translation by Igor Orellana at
    http://www.cad.dp.ua/stats/alfaq_ru.htm
  A german translation by myself at
    http://xarch.tu-graz.ac.at/autocad/news/faq/autolisp.html.de
+ A new spanish translation by Eduardo Magdalena
+   http://www.peletash.com/mecanicad/articulos/art02_0002.htm

  A greek translation is in progress.
  Relevant AutoDesk FAQ's and TechSupport
    http://www.autodesk.com/support/autocad/
    http://search.autodesk.com/query.html?qt=autocad+faq
    http://www.autodesk.com/support/autocad/asa2000.htm
  AutoDesk news groups
    news://discussion.autodesk.com/autodesk.autocad.customization
    New WebX interface at http://discussion.autodesk.com
    http://groups.google.com/groups?oi=djq&as_ugroup=autodesk.autocad.customization

--
Reini Urban, Jun 25, 2002
