The use of ":" and "->" in AutoLISP

Question

;;----------------=={ Add Objects to Block }==----------------;;
;;                                                            ;;
;;  Adds all objects in the provided SelectionSet to the      ;;
;;  definition of the specified block.                        ;;
;;------------------------------------------------------------;;
;;  Author: Lee Mac, Copyright © 2011 - www.lee-mac.com       ;;
;;------------------------------------------------------------;;

(defun LM:AddObjectstoBlock ( doc block ss / lst mat )

    (setq lst (LM:ss->vla ss)
          mat (LM:Ref->Def block)
          mat (vlax-tmatrix (append (mapcar 'append (car mat) (mapcar 'list (cadr mat))) '((0. 0. 0. 1.))))
    )
    (foreach obj lst (vla-transformby obj mat))

    (vla-CopyObjects doc (LM:SafearrayVariant vlax-vbobject lst)
        (vla-item (vla-get-Blocks doc) (cdr (assoc 2 (entget block))))
    )
    (foreach obj lst (vla-delete obj))
    (vla-regen doc acAllViewports)

This is the first time I have seen this type of syntax being used in AutoLISP.

I am trying to get some explanation of what "LM:" actually means.

The use of "Ref->" is also a question for me. "Ref" does not seem to be defined so it seems it must be part of the system somehow although I could not pull out any documentation describing such use of "Ref->".

Why is the local variable ss being accessed with "LM:ss->"?

Thank you.

Answer 1

This type of syntax is not construction of AutoLISP/Visual LISP. it's Lee Mac's standard. I understand it in this way:

"LM:" actually means shortcut of "Lee Mac" ;)

(LM:ss->vla ss) shound switch datatype from selection set to list of vla-objects where selection set is something simmilar to list of selected elements, but defined as type entity, not vla-object. Maybe get by (ssget) or (ssgetfirst)

(LM:Ref->Def block) get block definition based on it's reference. where "LM:Ref->Def" is only full name of function. "Ref" is not any kind of variable, it's part of function name.

"LM:ss->" not means that we use ss defined as parameter of function, but "LM:ss->vla" is name of function.