Is it possible to use local variables in dwg file and display them in text objects?
For example, I need to numerate objects starting with some value:
value0 = 5
value1 = value0 + 1
value2 = value0 + 2
etc...
Can I put value1 and value2 into some text object on my drawing?
User variables will certainly work. Be aware that they are limited in number and other programs may also set them without your knowing.
If you want simple values to be be displayed as text AutoCAD can do that. The scope of variables is up to you and the api you choose. (VB, VBA, AutoLisp, .NET etc.)
There are other data storage options available in the dwg file.
To display an integer in a TEXT or MTEXT (or attribute) object you insert a field, select DieselExpression as the field type and then type your expression. You can do this for other data types as well.
There are various user variables available for the task. To achieve the above, type the following into the AutoCAD command prompt:
setvar useri1 5 (sets the value of user integer1 to 5)
Then you can use the following DieselExpressions in fields inside different text objects:
$(getvar, useri1) (gets the value of useri1)
$(+,$(getvar,useri1),1) (add 1 to the value of useri1)
$(+,$(getvar,useri1),2) (add 2 to the value of useri1)
etc...
It would help to know what language you prefer to use. This is very easy to do using AutoLISP. Suppose you'd like a program to ask the user for a number, then proceed forward to increment that number and put the increments successively into drawing text (say lot numbers).
Here is a working and complete little sample of how you'd do something like this:
(defun c:consecunum ( / entget_in entsel_in value_in value_out)
(setq
value_in (getint "\nFirst number: ")
value_out value_in
)
(while (setq entsel_in (entsel (strcat "\nText to replace with \"" (itoa value_out) "\": ")))
(setq entget_in (entget (car entsel_in)))
(entmod
(subst
(cons 1 (itoa value_out))
(assoc 1 entget_in)
entget_in
)
)
(setq value_out (1+ value_out))
)
)
If you have any questions about how this works, don't hesitate to ask.
Related
So I'm making a simple function in autolisp to count the number of a specific block in a drawing, and it looks like this:
(defun c:contarblocos()
(setq ss (ssget "x" ' ((0. "INSERT") (2. "Nome do bloco"))))
(setq count (sslength ss))
(alert(strcat "Total de blocos no desenho: " (itoa count)))
)
Now, what I really want is to count the number of blocks in a specific area, defined by the user. In other words, the user will call the function, and then the function will ask for a specific area, where it will look for the specific block and count them, not counting any blocks from outside the selected area.
Rather than using the x mode string of the ssget function (which searches the entire drawing database for all entities which fulfil the criteria of the filter list argument), simply omit this argument to permit the user to make a selection using any valid selection method, e.g.:
(defun c:contarblocos ( / sel )
(if (setq sel (ssget '((0 . "INSERT") (2 . "Nome do bloco"))))
(alert (strcat "Total de blocos no desenho: " (itoa (sslength sel))))
)
(princ)
)
There are a few other issues with your current code:
Always declare the variables whose scope is local to your function: in my above example, you will note that the sel symbol is declared in the variable list within the defun expression. For more information on why this is important, you may wish to refer to my tutorial here.
You should test whether ssget returns a valid selection set before calling the sslength function to obtain the number of items in the set, since (sslength nil) will error. You will see that I use an if statement in my code to accomplish this.
The ssget filter list argument should be an association list of dotted pairs, and as such, there should be a space between the key and the value in each list item, hence this:
(0. "INSERT")
Should become:
(0 . "INSERT")
You should include a final (princ) or (prin1) expression within the defun expression so that the function returns a null symbol to the command line, rather than returning the value returned by the last evaluated expression (i.e. the alert expression, which will return nil). Including a (princ) expression per my example will ensure that the function exits 'cleanly'.
I'm writing code where the user picks from a list of choices. I have defined my list in the following:
;contains the options the user can pick
(define choices (list "choice1" "choice2" "choice3" "choice4" "choice5" "choice6" "OPENING VALUE" "HIGHEST VALUE" "LOWEST VALUE" "CLOSING VALUE" "VOLUME OF SHARES" "ADJUSTED CLOSING VALUE"))
My button gets the name from the list from the following code(only showing one example). In this case it takes the third item from the list:
[label (list-ref choices 2)]
and when I want to change the name then I use the line of code:
(send choice-4-9 set-label (list-ref choices 9))
My prof commented that I should bind names to 6 7 etc so your code would be readable. I'm still a little confused on what he meant by that and how I would do so.
He means for each index, define an identifier bound to that index, ideally named after what it means, e.g.:
(define choice1 0)
(define choice2 1)
(define choice3 2)
....
So now you can write [label (list-ref choices choice3)] instead of [label (list-ref choices 2)]. The code is more readable, and easier to change if necessary because you can change the binding of the identifier rather than every place where the number appears in code.
Incidentally, what you're doing now is called using "magic numbers."
The previous answer is good and I have upvoted it. I only want to mention that a common data structure for something like this is an association list, where you associate something like a symbol or number to a value, and then look it up using assq, assv, or assoc depending on the whether your lookup name requires eq?, eqv?, or equal? respectively. Consider:
(define choices
'((shoot . "Shoot!")
(run . "Run away!")
(reload . "Reload")
(appraise . "Search your surroundings")))
(define (get-label choice)
(let ((result (assq choice choices)))
(if (not result)
(error "???") ; handle as you see fit
(cdr result))))
;;;;;;;;;;;;;;;;
Welcome to DrRacket, version 6.4 [3m].
Language: racket/base [custom]; memory limit: 8192 MB.
> (get-label 'shoot)
"Shoot!"
>
I created a function which gets two string parameters. The function simply adds each string length. below is a code.
(defun add_twostring_length (mystr1 mystr2)
(+ (length mystr1) (length mystr2))
)
When I call add_twostring_length function like this,
(add_twostring_length "cpp" "lisp")
output is correct. 7
But, when I call the same function in the manner of using comma,
(add_twostring_length "cpp", "lisp")
I got an error message.
Error: Comma not inside a backquote.
[condition type: READER-ERROR]
I want to call function in the manner of (add_twostring_length "cpp", "lisp").
What is the wrong with the code?
picture showing error message
You might as well ask "why can't I call the function without parentheses?" In lisp, you call functions as an sexpr with the function in the car and the arguments in the cdr. There are no commas involved -- that's the syntax of lisp.
What you want is possible, but I will strongly advice against using it:
(set-macro-character #\,
#'(lambda (stream char)
(read stream t nil t)))
The above code creates the so called "read macro". At read-time common lisp will find all occurrences of , and ignore them. This makes possible calling functions like so:
(+ 1, 2, 3) ; => 6
However this will break escaping in templates:
`(1 2 ,(+ 3 4)) ; => (1 2 (+ 3 4))
Perhaps it is possible to make the read macro more intelligent, but I don't want to delve deeper into this, because I don't like the idea. Sorry.
How to add a common prefix/suffix to a list of strings?
For example:
From ("abc" "123" "xy")
To ("pre_abc" "pre_123" "pre_xy")
Try
(mapcar (lambda (c) (concat "pre_" x)) '("abc" "123" "xy"))
In Emacs without third-party libraries you use mapcar function to apply a function to every element of the list, as #sds have shown. However if you program in Elisp heavily, i recommend installing 2 third-party libraries, dash.el for list manipulation and s.el for string manipulation. These libraries introduce a huge amount of auxiliary functions with a consistent naming scheme. dash.el also have anaphoric versions for many functions, which makes code even less verbose. So to add a prefix for every string in a list you could use --map and s-prepend (s-append for suffixes):
(--map (s-prepend "x" it) '("a" "b" "c")) ;; => ("xa" "xb" "xc")
The operation to prepend is (concatenate 'string <strings ...)
So you could achieve your goal with
(cl-loop
for item in '("abc" "123" "xy")
collect (concatenate 'string "pre_" item))
A more general way to compose/generate strings would be to use format
using format would be
(cl-loop
for item in '("abc" "123" "xy")
collect (format nil "pre_~S" item))
Note using cl-lib package
I'd like to export or replicate a scheme environment in another guile process. The algorithm I'm imagining would do something like this to serialize:
(map (lambda (var val) (display (quasiquote (define ,var ,val))
(newline))
(get-current-environment))
And then I'd read/eval that on the other end.
However, while there are functions that return the current environment, they are in some internal format that I can't just map across. How can I "walk" the environment as the above? Alternatively, how else can I replicate an environment into another process?
you may decompose the so-called "current-environment" like this:
(define (get-current-binding-list)
(let* ((e (current-module)) ;; assume checking current-module
(h (struct-ref e 0)) ;; index 0 is current vars hashtable
)
(hash-map->list cons h) ;; return a vars binding list
))
and you can call (get-current-binding-list) to get variables binding list in current-module.
Please note that each element in this list is a pair of symbol and variable type, say, (symbol-name . variable-type). So you may print it like this:
for a instance ,you got a var binding:
(define abc 5)
then:
(let ((vl (get-current-binding-list)))
(assoc-ref vl 'abc)
)
==> #<variable 9bb5108 value: 5>
This result is a "variable type" of variable "abc". You can get it's value with variable-ref procedure.
So you can trace all the bindings and do something ,in your code ,it's simply print var-name and var-value.
I know my answer is too brief, but I think there's enough information to help you to find more details in the manual.
Hope this will help you.
You can't really serialize Scheme environment. I don't known even it's possible to (portably) serialize continuations. Oh, and don't forget about FFIs. Ports and threads are unserializable too.