Topic: There's got to be a better way

[nivuahc]

There's got to be a better way

I posted a tiny bit of code in this thread earlier today that I threw together yesterday when my brain took a detour from work for a bit. Anyway, I threw it together because I wanted to refresh my mind a bit when it comes to building lists and processing them (I haven't written any code in forever and I have a framework of an idea for a routine, this being part of it).

Anyway, what I actually wanted to do was build a list of layers that I could parse through and this is what I came up with:

Code: [Select]

;*********************************************************************************
; Function to build a list of available layers - © Copyright 2005 by Chuck Chauvin
;*********************************************************************************
(defun BuildLayerList (/ LayerItem)
  (setq LayerList nil)
  (setq LayerItem (tblnext "LAYER" T))

  (while (/= LayerItem nil)
    (setq LayerList
   (append LayerList
   (list
     (list
       (cdr (assoc 2 LayerItem))  ;; Name
       (cdr (assoc 62 LayerItem)) ;; Color
       (cdr (assoc 6 LayerItem))  ;; Linetype
     ) ;_end list
   ) ;_end list
   ) ;_end append
    ) ;_end setq LayerList
    (setq LayerItem (tblnext "LAYER"))
  ) ;_end while
 
  (princ)
) ;_end defun BuildLayerList
This started out as me thinking "build a list of layers that are in the drawing along with their linetypes". That was simple enough to do but, along the way I thought "well, maybe I'll want to throw the color in there as well" so I added that bit as an afterthought. Anyway, the above code will build a list that looks like this:

Code: [Select]

(("0" 7 "Continuous") ("LAYER_1" 7 "Continuous") ("LAYER_2" 5 "Dashed") ("LAYER_3" 150 "Hidden"))
that I can then use later on, in this skeleton of a routine I've got floating around in my skull.

Anyway, my gut tells me this isn't the most efficient way (with LISP) to do this and I was wondering if anyone had any thoughts or suggestions (using LISP) to make this better.

[Kerry]

Chuck, Thats about as efficient as you'll get .. if you consider return on investment, and if you're not chasing milliseconds.

I have a similar functionality using Vlisp which grabs the Layers Collection and iterates it collecting the properties from each Layer object, including some status info.  I doubt it is much faster or slower than yours.

 

[Jόrg Menzi]

That's what I would use

Code: [Select]

(defun BuildLayerList ( / LayerItem LayerList)
 (while (setq LayerItem (tblnext "LAYER" (not LayerItem)))
  (setq LayerList
   (cons
    (list
      (cdr (assoc 2 LayerItem))  ;; Name
      (cdr (assoc 62 LayerItem)) ;; Color
      (cdr (assoc 6 LayerItem))  ;; Linetype
    ) ;_end list
    LayerList   
   ) ;_end append
  ) ;_end setq LayerList
 ) ;_end while
 (reverse LayerList)
) ;_end defun BuildLayerListUsing 'cons' instead of 'append' is remarkable faster... and 'tblnext' can be controlled by his return value. Note, the LayerList variable isn't anymore global. The function returns the value now, strictly speaking the correct way to program sub's.

Cheers

[MP]

Code: [Select]

(defun ForFun ( / data result )
    (while (setq data (tblnext "layer" (null data)))
        (setq result
            (cons
                (mapcar
                   '(lambda (key) (cdr (assoc key data)))
                   '(2 62 6)
                )
                result
            )
        )
    )
)

[Joe Burke]

One other wrinkle if you work ObjectDBX and this is a toolbox function. It may make sense to pass the document as an argument. This way the function isn't limited to the active document.

This version filters out xref layers. but you get my drift.

Code: [Select]

(defun GetLayers ( doc / layers layname laylst )
  (setq layers (vla-get-Layers doc))
  (vlax-for x layers
    (setq layname (vlax-get x 'Name))
    ;filter out xref layers
    (if (not (vl-string-search "|" layname))
      (setq laylst (cons layname laylst))
    )
  )
  (acad_strlsort laylst)
) ;end


[MP]

If you want the same data via an activex route (including objectdbx) ...

Code: [Select]

(defun ForFun2 ( document / result )
    (vlax-for layer (vla-get-layers document)
        (   (lambda (data)
                (setq result
                    (cons
                        (mapcar
                           '(lambda (key) (cdr (assoc key data)))
                           '(2 62 6)
                        )
                        result
                    )
                )
            )
            (entget (vlax-vla-object->ename layer))
        )   
    )
)

[MP]

OT: It's really good to see you posting again Chuck.

[nivuahc]

OT: It's really good to see you posting again Chuck.

thankee

[MP]

And for completeness ...

Code: [Select]

(defun ForFun3 ( document / result )
    (vlax-for layer (vla-get-layers document)
        (setq result
            (cons
                (mapcar
                   '(lambda (property) (vlax-get layer property))
                   '(name color linetype)
                )
                result
            )
        )
    )
)

[Kerry]

.. As I said Chuck, depends if you're chasing milliseconds. Yours is still firmly in the running.

160 cycles per second <256 in 1.6> is pretty good.

Code: [Select]

Benchmarking [M.P. 2005] ...........Elapsed milliseconds for 256 iteration(s)/ relative Timing :

    (FORFUN3 KBSG:ACTIVEDOC)..........2113 / 1.4068 <slowest>
    (GETLAYERS_XX KBSG:ACTIVEDOC).....1913 / 1.2736
    (FORFUN)..........................1742 / 1.1598
    (BUILDLAYERLIST)..................1622 / 1.0799
    (BUILDLAYERLIST_JM)...............1512 / 1.0067
    (FORFUN2 KBSG:ACTIVEDOC)..........1502 / 1 <fastest>

This is a variation on the ActiveX method included.

Code: [Select]

(defun GetLayers_xx (document / laylst) 
  (vlax-for each (vla-get-layers document)
    (setq laylst (cons (list (vlax-get each 'Name)
                             (vlax-get each 'Color)
                             (vlax-get each 'LineType)
                       )
                       laylst
                 )
    )
  )
)
PS:
I've excluded Joe's from the test because the functionality is different

[MP]

... and to put Kerry's comments into perspective ... in a drawing with 1000 layers the delay is imperceptable (~ 60 milliseconds) with the slowest function in the lot; with 10000 layers it's still under 1 second (~ 680 milliseconds). (WXPP, P4, 3GHz, 1 GB RAM).

[CAB]

Nice examples of looping & collecting table data.

Thanks Fellas.

[ElpanovEvgeniy]

Code: [Select]

(defun test6 (i)
 (if (setq i (tblnext "LAYER" (not i)))
  (cons
   (mapcar '(lambda (x) (cdr (assoc x i))) '(2 62 6))
   (test6 t)
  ) ;_  cons
 ) ;_  if
)

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_$
Benchmarking ...............Elapsed milliseconds / relative speed for 4096 iteration(s):

    (TEST6 nil)..............1047 / 14.45 <fastest>
    (GETLAYERS DOC)..........6969 / 2.17
    (FORFUN2 DOC)............7890 / 1.92
    (BUILDLAYERLIST_JM)......8453 / 1.79
    (BUILDLAYERLIST).........8563 / 1.77
    (FORFUN).................8937 / 1.69
    (GETLAYERS_XX DOC)......14546 / 1.04
    (FORFUN3 DOC)...........15125 / 1 <slowest>

 
_$

[MP]

Code: [Select]

(defun test6 (i)
 (if (setq i (tblnext "LAYER" (not i)))
  (cons
   (mapcar '(lambda (x) (cdr (assoc x i))) '(2 62 6))
   (test6 t)
  ) ;_  cons
 ) ;_  if
)
(test6 nil) vs (test6 t) makes a big difference eh?

[ElpanovEvgeniy]

I apologize, I have made a mistake, wanted it to corrected but have made even more!

Code: [Select]

(defun test7 (i)
 (if (setq i (tblnext "LAYER" i))
  (cons
   (list
     (cdadr i)
     (cdr(cadddr i))
     (cdar(cddddr i))
    ) ;_  mapcar
   (test7 nil)
  ) ;_  cons
 ) ;_  if
)

Code: [Select]

Benchmarking .............Elapsed milliseconds / relative speed for 1024 iteration(s):

    (FORFUN2 DOC)...........1797 / 1.98 <fastest>
    (TEST7 T)...............1937 / 1.84
    (BUILDLAYERLIST_JM).....1984 / 1.8
    (BUILDLAYERLIST)........2000 / 1.78
    (FORFUN)................2094 / 1.7
    (GETLAYERS_XX DOC)......3359 / 1.06
    (FORFUN3 DOC)...........3562 / 1 <slowest>