clautolisp Extensions

This sub-tree documents host-interaction helpers that are not present in either AutoCAD or BricsCAD. They are clautolisp-specific additions that improve interactive AutoLISP development without colliding with the vendor namespace. To make the distinction obvious at every call site, the entries use a reserved CLAL- prefix; no Autodesk- or Bricsys-documented identifier has ever used that prefix.

A clautolisp-only program that calls a CLAL- function will not run unchanged on AutoCAD or BricsCAD: (boundp 'clal-sysvar-list) returns nil there. Portable code that wants to ride the extension when available should probe with boundp before calling:

(if (boundp 'clal-sysvar-list)
    (clal-sysvar-list)
    ;; vendor fallback — there isn't one; either accept that the
    ;; query is unavailable or shell out to the SETVAR command.
    nil)

• These functions are defined by clautolisp; there is no Autodesk or Bricsys reference page.
• The source of truth is the entries below, the spec-level inventory at autolisp-spec/documentation/system-variables- inventory.sexp, and the host-side implementation under clautolisp/autolisp-builtins-core/source/api.lisp.