Lisp In Autocad
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Introduction to Visual LISP Editor Inside AutoCAD (VLISP) 1. Start AutoCAD. In the Tools menu select AutoLISP and then select Visual LISP Editor. AutoLISP is a dialect of Lisp programming language built specifically for use with the full version of AutoCAD and its derivatives, which include AutoCAD Map3D, AutoCAD Architecture and AutoCAD Mechanical. AutoLISP is a programming language designed specifically for use with the full version of AutoCAD (i.e. It does not work with AutoCAD LT). AutoLISP is one of a number of Application Programming Interfaces (APIs) built into AutoCAD but it is probably the easiest to use and therefore the most productive for the beginner.
Lists had been the most important and the primary composite data structure in traditional LISP. Present day's Common LISP provides other data structures like, vector, hash table, classes or structures.
Lists are single linked lists. In LISP, lists are constructed as a chain of a simple record structure named cons linked together.
The cons Record Structure
A cons is a record structure containing two components called the car and the cdr.
Cons cells or cons are objects are pairs of values that are created using the function cons.
The cons function takes two arguments and returns a new cons cell containing the two values. These values can be references to any kind of object.
If the second value is not nil, or another cons cell, then the values are printed as a dotted pair enclosed by parentheses.
The two values in a cons cell are called the car and the cdr. The car function is used to access the first value and the cdr function is used to access the second value.
Example
Create a new source code file named main.lisp and type the following code in it.
When you execute the code, it returns the following result −
Running Lisp In Autocad
The above example shows how the cons structures could be used to create a single linked list, e.g., the list (A B C) consists of three cons cells linked together by their cdrs.
Diagrammatically, it could be expressed as −
Lists in LISP
Although cons cells can be used to create lists, however, constructing a list out of nested cons function calls can't be the best solution. The list function is rather used for creating lists in LISP.
The list function can take any number of arguments and as it is a function, it evaluates its arguments.
The first and rest functions give the first element and the rest part of a list. The following examples demonstrate the concepts.
Example 1
Create a new source code file named main.lisp and type the following code in it.
When you execute the code, it returns the following result −
Example 2
Create a new source code file named main.lisp and type the following code in it.
When you execute the code, it returns the following result −
List Manipulating Functions
The following table provides some commonly used list manipulating functions.
| Sr.No. | Function & Description |
|---|---|
| 1 | car It takes a list as argument, and returns its first element. |
| 2 | cdr It takes a list as argument, and returns a list without the first element |
| 3 | cons It takes two arguments, an element and a list and returns a list with the element inserted at the first place. What makes serial killers one of the most terrifying people on earth is that when wreaking havoc, anybody at all can be a victim. Many of the worst serial killers recorded in history were just. Moses Sithole. Moses Sithole (born 17 November 1964) also known as the “ABC Killer” or “The South African Strangler” has come to be widely known as South Africa’s most evil serial killer. Sithole committed 38 murders and raped 40 women in 1995. To the people around him, Sithole appeared to be a mild-mannered individual. Famous south african serial killers. Dec 22, 2014 There are well documented cases of African-American, Latino, and Asian-American serial killers. African-Americans make up the largest racial minority group among serial killers, representing. As of October 2014, South Africa had 160 recorded serial killers since 1950. A disproportionately large number them were white males, although no racial group were more likely to be victims. A disproportionately large number them were white males, although no. Samuel Sidyno. This South African serial killer went by the name the “Capital Hill Serial Killer” and was convicted of killing 7 people in Pretoria between 1998 and 1999. Described as a sadist and psychopath, Sidyno was sentenced to multiple life terms. |
| 4 | list It takes any number of arguments and returns a list with the arguments as member elements of the list. |
| 5 | 3d mannequin free download. append It merges two or more list into one. |
| 6 | last It takes a list and returns a list containing the last element. |
| 7 | member It takes two arguments of which the second must be a list, if the first argument is a member of the second argument, and then it returns the remainder of the list beginning with the first argument. |
| 8 | reverse It takes a list and returns a list with the top elements in reverse order. |
Please note that all sequence functions are applicable to lists.
Example 3
Lisp In Autocad Lt
Create a new source code file named main.lisp and type the following code in it.
When you execute the code, it returns the following result −
Concatenation of car and cdr Functions
The car and cdr functions and their combination allows extracting any particular element/ member of a list.
However, sequences of car and cdr functions could be abbreviated by concatenating the letter a for car and d for cdr within the letters c and r.
For example we can write cadadr to abbreviate the sequence of function calls - car cdr car cdr.
Thus, (cadadr '(a (c d) (e f g))) will return d
Example 4
Create a new source code file named main.lisp and type the following code in it.
When you execute the code, it returns the following result −
An AutoLISP file must be loaded into the AutoCAD program before it can be ran.
Lisp In Autocad Lt
- Open an AutoLISP (LSP) file and make sure the text editor is active.
- In Visual LISP, do one of the following:
- From the menu bar, click Tools Load.
- From the Run toolbar, click Load Active Edit Window.
A message is displayed in the Console window if the program was loaded successfully.
- Start the AutoLISP function by doing one of the following:
- At the Visual LISP Console window prompt, enter the name of a command or function name in parentheses, and press Enter.
- At the AutoCAD Command prompt, enter the name of a command or function name in parentheses, and press Enter.
If you switch back to Visual LISP before the command or function ends, the mouse pointer will appear as the Visual LISP icon. Switch back to AutoCAD and complete the command or function.
- Respond to any prompts or dialog boxes that are displayed.
Example
This example requires the installation of the Visual LISP Sample files.
- In Visual LISP, click File Open File.
- In the Open File dialog box, browse to the SampleVisualLISP folder, which is located in your AutoCAD installation directory.
- Double-click the drawline.lsp file.
- Make sure the text editor window containing the drawline.lsp program is active. If you are not sure whether the window is active, click anywhere in the window to activate it.
- Click the Load Active Edit Window button from the Run toolbar, or click Tools Load Text in Editor.
Visual LISP responds by displaying a message in the Console window indicating it has loaded the program.
- Run the drawline function from the Console prompt by entering the function name in parentheses, then pressing Enter:
The drawline function will prompt you to specify two points, and will then draw a straight line between those points. When drawline prompts for user input, Visual LISP turns control over to AutoCAD to prompt for the points. What you see next depends on whether or not the AutoCAD windows are currently displayed on your desktop. If AutoCAD is already maximized, you will see the AutoCAD windows. But if AutoCAD is currently minimized, the windows will not automatically be restored and displayed. Instead, Visual LISP remains visible and your mouse pointer changes to a Visual LISP symbol.
This symbol indicates that the Visual LISP window is no longer active. If this is the case, you must manually switch to the AutoCAD window. Click the AutoCAD icon on the Windows task bar to activate AutoCAD.
- Respond to the prompts by specifying points in the drawing area or at the Command prompt.
After you respond to the prompts, control returns to Visual LISP and you will once again see the Visual LISP window.
When you enter commands in the Visual LISP Console window or run a program loaded from the text editor, you may be frequently switching back and forth between the Visual LISP and AutoCAD windows. Aside from using the standard Windows methods of switching between windows, you can activate the AutoCAD window by choosing Window Activate AutoCAD from the Visual LISP menu, or by clicking the Activate AutoCAD button on the Run toolbar. If you are in AutoCAD and want to return to the Visual LISP environment, you can click its icon on the Windows task bar, or enter vlisp at the Command prompt or click Manage tab Applications panel Visual LISP Editor.