lisp legal

7/31/2019 Lisp Legal

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Objectives

To lay a firm foundation of the basics of VisualLisp.

Prepare you to write your own Visual Lisproutines

Start you down the path to official AutoCADGurudom ( or Nerdom)

Teach you some quick and dirty basics of VisualLisp (dont look too close!).

Discover new ways to torture your coworkers!


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Hold on - we have a lot of information tocover in 80 minutes!


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First and Foremost!Dont let Visual Lisp intimidate you!


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What does LISP stand for?

LISt Processor

(not Lost In Stupid

Parentheses!)


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The Basics

Lists

Functions

Arguments Golden Rules of AutoLISP


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What is a LIST?

Anything inside of parentheses

Examples of LISTS:

(a b c)

(setq x 1)

(princ)


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What is a FUNCTION?

(or subr)The ACTION you want Visual Lisp to do!


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In Visual Lisp the function ALWAYSgo first!!!

Visual Lisp uses Prefix notation

Example: (+ 1 2)(- 5 3)

(inters A B C D)

(setq x 3)


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Visual Lisp as a Calculator

INFIX Notation(1 + 1)

(3 * 4)

(6 / 2)PREFIX Notation

(+ 1 1)

(* 3 4)

(/ 6 2)


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Arguments

Arguments are the values you pass to afunction

(+ 5 6)

+ is the function

5 and 6 are the arguments

(setq x Autodesk)

Setq is the functionX and Autodesk are the

arguments


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The Golden Rules of Visual Lisp

For every open paren, you must have aclosed paren

Example: (setq x (+ a b))

For every open double quote, you must

have a closed double quote.

Example: (prompt How are you?)


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The Key to unlocking complicatedLISP routines:

Visual Lisp works from the Inside Out(+ 5 (* 4 3))

is equal to

(4 * 3) + 5(- (+ 5 2) (* 6 (- 7 6)))

is equal to

(5 + 2) - (6 * (7 - 6))

7 - (6 * 1)


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Quiz Time!

(* 4 (/ (+ 6 3) 3))12

(+ (* (- 5 2) (/ 15 3)) 6)21

(/ (* (- 11 9) (+ 25 5)) (* 3 2))

10


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Some popular Data Types:

Real Numbers 1.5

Integers 5

Strings LINE Lists (8 . DIM)

Subrs (or functions) SETQ


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Real Numbers and Integers

Real Numbers have decimal pointsExample: 1.3 5.0

Integers do not!

Example: 25 11

Real Numbers must have a leading zero.

.5 is incorrect 0.5 is correct

Dotted pair: (0 . CIRCLE)

error: misplaced dot on input


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(/ 7 2) => 3

(/ 7 2.0) => 3.5(+ 1 2 3 4 5 6. ) => 21.0

(+ 1 .5) => invalid dotted pair

(+ 1 0.5) => 1.5

One real number changes the entire pot!


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Basic Arithmetic Functions(for you math-heads):

+ = addition * = multiplication

/ = division - = subtraction

(sqrt x) (sin ang) (atan x)

(expt x y) (cos ang)

(abs x) (log x)

(float x) (fix x)


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btw...

Angles are measured in radians!

(not degrees)

and youll need to remember that.


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Strings

Usually Text (literals)

Always double-quoted

Spaces accepted

Examples: autodesk

line

1.25


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Setting Variables

(SETQ)

(SETQ X 1)

SETQ is the functionX is the variable name

1 is the value

Setting several variables at once:(SETQ A 1 B 2 C 3)


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Variable Names

Alpha-numeric

May not contain spaces

should not replace existing preset valuessuch as T or pi

Note: A variable that hasnt been set isequal to nil


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Using Visual Lisp variables inAutoCAD

(setq X 1 Y 2)

Command: !Xreturns 1

Command: circle

3P/2P/TTR/:

Diameter/:!Y


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Ways to ruin your Visual Lisp life

(setq + -)

(setq * /)

(setq pi 2.5)

Visual Lisp will let you abuseyourself. . .


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Using AutoCAD commandsin Visual Lisp (the good stuff!)

Using the COMMAND function, you canaccess the AutoCAD commands

Example:(command QSAVE)

(command TRIM)

(command ZOOM P)

(command LAYER)

B d f lt Vi l Li d t


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By default, Visual Lisp doesntdisplay dialog boxes

Visual Lisp displays the command line interfacefor commands.

To force the dialog box use:(initdia)

Before the command:

(initdia)

(command layer)


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pause allow for user input

(command) cancel

enter


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(Command ZOOM A)

(Command ERASE L )

(Command INSERT DESK pause 1 1 pause)

(Command LINE A B C C)

(Command TEXT pause .5 0 Visual Lisp)

(Command LAYER S pause )(Command)


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Creating your own AutoCAD

Commands(DEFUN)DEFUN binds a set of expressions to a

variable.

(DEFUN C:ZAP ( )

Command: zap


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DEFUN

is the function

C:indicates the function will be an

AutoCAD command

( )indicates no local variables and noarguments (well get to that another

time!)

Anatomy of DEFUN


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DEFUN examples

(DEFUN C:ZA ( )

(Command ZOOM A)

)

(DEFUN C:SQ ( )(Command POLYGON 4 E pause pause)

)

(DEFUN C:ZAP ( )

(Command erase all ))

S O S


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SHORT.LSP(defun c:ls ( )(command layer M pause )

)

(defun c:ZO ( )

(command ZOOM O)

)

(defun c:ttr ( )(command circle ttr pause pause pause)

)

(defun c:Jellydonut ( )(command donut 0 pause )

)


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Loading Visual Lisp routines

APPLOAD - used to load one or more VisualLisp routines

(load short)


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Opening a dialog to a specific tab

(command +dialogname X)

(command +options 7)will open the Options dialog to tab #8

(command +customize 0)


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Whats wrong with this picture?

(defun c:door

(insert door pause 1 1 45)

)(defun c:fun ())

(prompt are we having fun yet?)

)


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PPurge.LSP

(Defun c:ppurge ( )

(command purge all * N))

Lets create a command that


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Lets create a command thatbreaks an object in the same

spot twice(defun c:crack ()


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Clean up your ACT!

PRINC (get rid of the nils!)


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PPurge.LSP

(Defun c:ppurge ( )

(command purge all * N)(princ)

)

Just for fun!


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Just for fun!

ALERT

ALERT sends an ALERT box to the screenwith the indicated text

Example:

(ALERT Formatting the hard drive)


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ACAD.LSP or ACADDOC.LSPAutomatic Visual Lisp Loading

Put frequently used Visual Lisp routines.

Undefine those AutoCAD commands youwant to automatically replace with VisualLisp routines.

Place partial menu loading instructions


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ACAD.LSP

(defun c:ZA ( )(command Zoom All)(princ))

(defun c:DT ( )

(setvar clayer TEXT)(command Dtext)(princ))

(defun c:bolt ( )(command insert bolt pause pause pause)(princ))


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Automatic loading LISP files

ACAD.LSP 2

ACADDOC.LSP 4

ACAD.MNL 5-------------

ACAD200X.LSP 1

ACAD200XDOC.LSP 3


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Undefine and Redefine

Permits undefining and redefining theinternal AutoCAD commands

Note: AutoCAD commands can always beexecuted with a leading period.

S STARTUP


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S::STARTUPa special section of ACAD.LSP

(defun C:LINE ( )(prompt Shouldnt you be using Polylines?)

(command PLINE))

(defun S::STARTUP ( )(command undefine line)

)

Note: s::startup is the last file to be loaded beforecontrol is handed over to the user.


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Ways to torture your coworkers:

ACAD.LSP

(defun c:qsave ( )(command undo b y)

(command .qsave .qsave)(defun s::startup ()

(command undefine save)(command undefine qsave)(command undefine saveas)

)


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one more means of torture:

(defun c:zoom ( )

(command erase L )

(command .zoom)

(princ)

)(defun c:redo ( )

(prompt You goofed - deal with it!)

)

(defun c:undo ( )(alert Get it right the first time!)


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(defun c:regen ()

(setvar cmdecho 0)

(command donut 0 300000000000 10,10)

(command regen)

(command cmdecho 1)

)(defun s::startup ( )

(command undefine zoom)

(command undefine undo)(command undefine redo)

(command undefine regen)

)

Other evil things to put in


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Other evil things to put ins::startup!

S::STARTUP

(setvar angbase 180)

OR

(setvar snapang 0.000001)

OR

(command vpoint 0,0,-1)(command ucsicon off)


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Whats wrong with this picture?

(1 + 1)(* 5 .25)

(/ 9 2)

(setq x (+ 1 2)

(defun d:dimwit

(command text .5 90 pause)

(alert hit cancel to exit dialog box)

(defun s:startup ( )


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Review

LISP stands for. . .

List

Function

Command pause

DEFUN

(princ) ( )

undefine

Acad.lsp

s::startup

string


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Lynn Allen

[email protected]

Lynns Blog

www.autodesk.com/blog
mailto:[email protected]://www.autodesk.com/bloghttp://www.autodesk.com/blogmailto:[email protected]

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