(defun cb:...)

[bartdewilde]

hello

 

i'm starting with autocad lisp

 

i've learnd that you start a routine with

 

(defun c:name ....)

 

 

but now i've found a program that start with

 

(defun cb:hdis (/ld)

 

this comes back with the variables

 

if (= (type cb:ld) 'str

 

i understand the meanig of this code exept what te cb: means

 

can someone tell me what's the difference between defun c: and defun cb:

[VVA]

By analogy to this article, I have written article on use of a code from a forum in Russian, where has a little expanded the description.

As I not so well know English, therefore I will take advantage of machine translation. I hope, it will be clear, and if is not present, me will correct.

 

Command or function?

 

To begin with it is necessary to be defined, that at us: a command or function?

It is a little theory.

In the description practically any code there is such line, as

(defun …

 

 

And then after her something there it is written. And so that there is written and is a function name.

If the first symbols are C:, function is ready to a call from a command line. If such is not present to cause function it is necessary, concluding her name in parentheses.

For example, there is a function

(defun c:test () )

 

 

It to cause since a command line it is possible directly:

 

Command: test

 

Also actions

And here the such:

(defun test () )

 

It will be possible to cause only so:

 

Command: (test)

 

Also actions .

From the point of view of AutoCAD'a it is 2 different modules

 

In your case it is function and it needs to be caused so: (cb:hdis)

[Commandobill]

I believe I've seen that lisp before. "cb:" doesnt actually do anything. That code is just a function. if you were to type in "hdis" as a command it wouldnt do anything. but if you were to use it like this (cb:hdis) it would run. Why they named it that way is unknown to me but im sure they had their reasons.

[Commandobill]

Too little too late it seems. Good description VVA

[Lee Mac]

Nice once VVA, but, yes, I believe its just irresponsible function naming...

[rkmcswain]

Nice once VVA, but, yes, I believe its just irresponsible function naming...

 

I wouldn't bet on it... I do this all the time. Useful for identification.

[David Bethel]

I wouldn't bet on it... I do this all the time. Useful for identification.

 

 

I agree. I use function name prefixes all of the time. My preference is to use an underscore delimiter , but a colon is just as valid. My $0.02 -David

[Lee Mac]

I wouldn't bet on it... I do this all the time. Useful for identification.

 

You mean using the function syntax as a prefix for sub_routines - I suppose its good for reference, but the function begins with a c..: I suppose it could confuse the LISP novice...

[rkmcswain]

Possibly, but still nothing wrong with it. I do this sometimes within the same file. Say my file (and main function is named) CHTXT - i might name my internal functions things like:

(defun chtxt:myfunc () 
 (blah_blah)
)

Of course, like David says, just my 2¢.