Vital LISP was a superset of the existing AutoLISP language that added VBA-like access to the AutoCAD object model, reactors (event handling for AutoCAD objects), general ActiveX support, and some other general Lisp functions. Vital-LISP, a considerably enhanced version of AutoLISP including an integrated development environment (IDE), debugger, compiler, and ActiveX support, was developed and sold by third party developer Basis Software. However, it has remained AutoCAD's main user customizing language. After that, its development was neglected by Autodesk in favor of more fashionable development environments like Visual Basic for Applications (VBA). The language was introduced in AutoCAD Version 2.18 in January 1986, and continued to be enhanced in successive releases up to release 13 in February 1995. History ĪutoLISP was derived from an early version of XLISP, which was created by David Betz. AutoLisp also has a built-in graphical user interface (GUI) mini- or domain-specific language (DSL), the Dialog Control Language, for creating modal dialog boxes with automated layout, within AutoCAD.

ĪutoLISP code can interact with the user through AutoCAD's graphical editor by use of primitive functions that allow the user to pick points, choose objects on screen, and input numbers and other data. The properties of these graphical entities are revealed to AutoLISP as association lists in which values are paired with AutoCAD group codes that indicate properties such as definitional points, radii, colors, layers, linetypes, etc.

Aside from the core language, most of the primitive functions are for geometry, accessing AutoCAD's internal DWG database, or manipulation of graphical entities in AutoCAD. AutoLISP is a small, dynamically scoped, dynamically typed Lisp language dialect with garbage collection, immutable list structure, and settable symbols, lacking in such regular Lisp features as macro system, records definition facilities, arrays, functions with variable number of arguments or let bindings.

Autocad lisp command