Topic: ===[CHALLENGE - hex fractal]===

[gile]

When I replace (command-s) with (vl-cmdf) on A2014 it works, but on A2017 it doesn't... Can you explain?

I can't explain, it seems there's something wrong (bug?) with vl-cmdf. The "hex0" block is not created.

Anyway, why don't you use command-s which is available since AutoCAD 2012 and  should be faster than both command and vl-cmdf?

[gile]

When I replace (command-s) with (vl-cmdf) on A2014 it works, but on A2017 it doesn't... Can you explain?

I got it.

This is due to the fact that vl-cmdf returns T if none of the arguments are nil while command-s always returns nil.
So, in the following expression:

Code - Auto/Visual Lisp: [Select]

1.       (or (tblsearch "BLOCK" "hex0")
2.           (command-s "_.polygon" 6 c "_inscribe" (polar c (/ pi 2) 1))
3.           (command-s "_.block" "hex0" c (entlast) "")
4.       )

both (command-s ...) expressions are executed while with:

Code - Auto/Visual Lisp: [Select]

1.       (or (tblsearch "BLOCK" "hex0")
2.           (vl-cmdf "_.polygon" 6 c "_inscribe" (polar c (/ pi 2) 1))
3.           (vl-cmdf "_.block" "hex0" c (entlast) "")
4.       )

only the first (vl-cmdf ...) expression is executed.

So, if you want to use vl-cmdf, just replace this expression with:

Code - Auto/Visual Lisp: [Select]

1.       (if (not (tblsearch "BLOCK" "hex0"))
2.         (progn
3.           (vl-cmdf "_.polygon" 6 c "_inscribe" (polar c (/ pi 2) 1))
4.           (vl-cmdf "_.block" "hex0" c (entlast) "")
5.         )
6.       )

[ribarm]

Thanks, that explains things...

FYI, (command-s) is just slightly slower than (vl-cmdf)... Test it for yourself :
https://forums.autodesk.com/t5/visual-lisp-autolisp-and-general/fit-arc-lisp-not-working-in-2017/m-p/7401334/highlight/true#M359125

M.R.

[gile]

From the tests I did using MP's Benchmark routine, command-s is slighty faster.

Never mind, if execution speed is an issue, don't use command/vl-cmdf/command-s at all, or better, don't use LISP...