what I am trying to do is trying to convert multiple entities into VLA-OBJECTS in prder to use the Vlisp functions available for them. What I am trying to do is:
(while (<= masa masas)
(set (read (strcat "off" (itoa masa) )) (cdr (assoc -1 (eval (read (strcat "offset" (itoa masa)))))))
(set (read (strcat "obj" (itoa masa) )) (vlax-ename->vla-object (read (strcat "off" (itoa masa) ))))
(setq masa (+ masa 1))
)
where masa is a counter that allows to go out of the while loop and masas is the variable limit. in wy code the first and the third line inside the while loop is working perfectly but the second one where I am trying to convert each ename into VLA object gives me the error bad argument type: lentityp OFF1 because in this case off starts in 1, I think the problem is not the uppercase result of read because lisp is not case-sensitive but rather than that a type problem that I can not solve. I also tried with eval or using directly assoc -1 but I have not been lucky.
The error message means OFF1 is not an ENAME (it's a symbol).
You need to evaluate the symbol value with (eval ...).
(while (<= masa masas)
(set (read (strcat "off" (itoa masa)))
(cdr (assoc -1 (eval (read (strcat "offset" (itoa masa))))))
)
(set (read (strcat "obj" (itoa masa)))
(vlax-ename->vla-object (eval (read (strcat "off" (itoa masa)))))
)
(setq masa (1+ masa))
)
IMO, you should rather use lists, instead of assigning all these incremented variables.
To use these variables, you'll need to loop through them with while or repeat as you could do with list and foreach.
Assuming offsetList is the list of the dxf lists (all your offset(n) values), you can simply build a list of enameS and a list of vla-objectS.
(setq offList (mapcar '(lambda (x) (cdr (assoc -1 x))) offsetList))
(setq objList (mapcar 'vlax-ename->vla-object offList))
Related
I started learning LISP last night and I am currently writing a text-based Hotel Room Bookings system in common LISP. These are the lines where I have initialized my lists and vars :
(defparameter *rooms* (list 0))
(defvar counter 0)
(defvar room-num 0)
The following is the piece of code where I am manipulating these to search through my list :
(loop
(setq room-num(read))
(if (and
(> counter 0)(equal t (find room-num '(*room*)))
)
(progn
(print "Room already exists:")
(return 1)
)
)
(push room-num (cdr (last *rooms*)))
(setq counter (+ counter 1))
)
The above code is appending room-num to the room list if it does not already exist in the list.
The problem I have is with finding room-num in room list.
Following is what I have tried (Sorry if the code pretty sloppy. As I said I started working with LISP just yesterday) :
(if (and (> counter 0)(equal (member room-num *room*)))
Also tried :
(if ((if (member room-num '(rooms)) t nil))
(print "Room already exists")
)
Any help would be appreciated.
also, in addition to #coredump 's answer, you could also use some existing common lisp facilities, like this (employing the loop macro):
(loop for counter from 0
for room = (read)
until (find room rooms)
collect room into rooms
finally (progn (format t "room ~a already exists in ~a~%" room rooms)
(return (values rooms counter))))
or this (employing do):
(let ((rooms))
(do ((counter 0 (1+ counter))
(room (read) (read)))
((find room rooms)
(format t "room ~a already exists in ~a~%" room rooms)
(values rooms counter))
(push room rooms)))
although it is not an answer, approaching to a problem using high level facilities can save plenty of debugging time.
This declaration is fine:
(defparameter *rooms* (list 0))
The following ones are not great:
(defvar counter 0)
(defvar room-num 0)
Special variables declared with defvar should be named with earmuffs, ie. a pair of asterisks, just like you did for the previous variable.
It is helpful when reading code to know that some variables are globals.
Also, you are writing a script that manipulates global state, instead of defining a function that only modifies a local state. For a small example this is ok, but a good exercise would be to encapsulate this script in a function.
(loop
(setq room-num(read))
(if (and
(> counter 0)(equal t (find room-num '(*room*)))
)
(progn
(print "Room already exists:")
(return 1)
)
)
(push room-num (cdr (last *rooms*)))
(setq counter (+ counter 1))
)
The formatting is unconventional, please follow an idiomatic style.
Here is your code reformatted:
(loop
(setq room-num (read))
(when (and (> counter 0)
(equal t (find room-num '(*room*))))
(print "Room already exists:")
(return 1))
(push room-num (cdr (last *rooms*)))
(setq counter (+ counter 1)))
I replaced (if A (progn B C)) by (when A B C), which is simpler to read.
Now, your problem is here:
(equal t (find room-num '(*room*)))
You are trying to find room-num in a list that literally contains the symbol *room*, and not the value of the variable named *room*.
This is because you quoted the list: '(*room*) is the same as (quote (*room*)), which when evaluated just return the form as read by the Lisp reader, i.e. a list of one symbol.
You just need to call (member room-num *room*) to test membership, and you do not have to compare the return value of (member ...) with t, using (equal t ...): if the test succeeds, it will be non-null, ie. true.
Also:
(push room-num (cdr (last *rooms*)))
You do not need to push the room as the last element, just put it in front with:
(push room *rooms*)
Order does not matter in your case anyway, and you avoid one traversal of the list for nothing with last.
In elisp, how can I get a destructuring bind for regex matches?
For example,
;; what is the equivalent of this with destructuring?
(with-temp-buffer
(save-excursion (insert "a b"))
(re-search-forward "\\(a\\) \\(b\\)")
(cons (match-string 1)
(match-string 2)))
;; trying to do something like the following
(with-temp-buffer
(save-excursion (insert "a b"))
(cl-destructuring-bind (a b) (re-search-forward "\\(a\\) \\(b\\)")
(cons a b)))
I was thinking I would have to write a macro to expand matches if there isn't another way.
Here is one way: you first extend pcase to accept a new re-match pattern, with a definition such as:
(pcase-defmacro re-match (re)
"Matches a string if that string matches RE.
RE should be a regular expression (a string).
It can use the special syntax \\(?VAR: to bind a sub-match
to variable VAR. All other subgroups will be treated as shy.
Multiple uses of this macro in a single `pcase' are not optimized
together, so don't expect lex-like performance. But in order for
such optimization to be possible in some distant future, back-references
are not supported."
(let ((start 0)
(last 0)
(new-re '())
(vars '())
(gn 0))
(while (string-match "\\\\(\\(?:\\?\\([-[:alnum:]]*\\):\\)?" re start)
(setq start (match-end 0))
(let ((beg (match-beginning 0))
(name (match-string 1 re)))
;; Skip false positives, either backslash-escaped or within [...].
(when (subregexp-context-p re start last)
(cond
((null name)
(push (concat (substring re last beg) "\\(?:") new-re))
((string-match "\\`[0-9]" name)
(error "Variable can't start with a digit: %S" name))
(t
(let* ((var (intern name))
(id (cdr (assq var vars))))
(unless id
(setq gn (1+ gn))
(setq id gn)
(push (cons var gn) vars))
(push (concat (substring re last beg) (format "\\(?%d:" id))
new-re))))
(setq last start))))
(push (substring re last) new-re)
(setq new-re (mapconcat #'identity (nreverse new-re) ""))
`(and (pred stringp)
(app (lambda (s)
(save-match-data
(when (string-match ,new-re s)
(vector ,#(mapcar (lambda (x) `(match-string ,(cdr x) s))
vars)))))
(,'\` [,#(mapcar (lambda (x) (list '\, (car x))) vars)])))))
and once that is done, you can use it as follows:
(pcase X
((re-match "\\(?var:[[:alpha:]]*\\)=\\(?val:.*\\)")
(cons var val)))
or
(pcase-let
(((re-match "\\(?var:[[:alpha:]]*\\)=\\(?val:.*\\)") X))
(cons var val))
This has not been heavily tested, and as mentioned in the docstring it doesn't work as efficiently as it (c|sh)ould when matching a string against various regexps at the same time. Also you only get the matched substrings, not their position. And finally, it applies the regexp search to a string, whereas in manny/most cases regexps searches are used in a buffer. But you may still find it useful.
I have a file that looks similar to:
AT 4
AT 5.6
AT 7.2
EG 6
EG 6
S 2
OP 3
OP 1.2
OP 40
and I want to compute the average (I've just made these averages up) for each of the titles and output something like:
AT 5.42
EG 6
S 2
OP 32.1
The file is in order, so all headings will be right under each other, but there are a varying amount of headings. eg. AT has three, but S only has one.
How would I sum together each of these lines, divide by the number of lines, and then replace all of the lines in emacs / elisp?
I decided to try to solve this question while still learning elisp myself. There is perhaps more efficient ways to solve this.
After defining the function, you'll want to set the region around the scores. (If the whole file, then M-<, C-SPC, M->) I figured this would be cleanest since your scores may be in the middle of other text. My function will compute the averages and then insert the answer at the end of the region.
(defun my/averages (beg end)
(interactive "r")
(let ((avgs (make-hash-table :test 'equal))
(answer "")
(curval nil)
(key nil)
(val nil))
; Process each line in region
(save-excursion
(goto-char beg)
(while (< (point) end)
; split line
(let ((split-line
(split-string
(buffer-substring-no-properties
(line-beginning-position) (line-end-position)))))
(setq
key (car split-line)
val (string-to-number (cadr split-line))
curval (gethash key avgs '(0 . 0)))
(puthash key (cons (+ (car curval) 1) (+ (cdr curval) val )) avgs))
; Advance to next line
(forward-line))
; Accumulate answer string
(maphash
(lambda (k v)
(setq answer
(concat answer "\n" k " "
(number-to-string (/ (cdr v) (car v))))))
avgs)
(end-of-line)
(insert answer))))
As a warning, I have zero error checking for lines that do not strictly meet your formatting.
You need libraries dash, s, f, and their functions -map, -sum, -group-by, s-split, f-read-text.
;; average
(defun avg (values)
(/ (-sum values) (length values)))
(-map (lambda (item)
(list (car item)
(avg (-map (lambda (x)
(string-to-number (cadr x)))
(cdr item)))))
(-group-by (lambda (item)
(car item))
(-map (lambda (line)
(s-split " " line t))
(s-split "[\n\r]"
(f-read-text "file.txt")
t))))
Presuming your file is called "file.txt", the code above returns (("AT" 5.6000000000000005) ("EG" 6) ("S" 2) ("OP" 14.733333333333334)).
After that you can convert that into text:
(s-join "\n"
(-map (lambda (item)
(s-join " "
(list (car item)
(number-to-string (cadr item)))))
This string you can write into file using f-write-text. Don't forget you can format ugly floating-point numbers like that:
(format "%.2f" 3.33333333) ; => "3.33"
I programmed some months ago some code with a lot of if statements. If region-active-p, if beginning-of-line, those kind of things.
Having learned about the cond lisp, I was wondering if I could improve my code a lot.
The problem is that this cond is only doing things when "true" as far as I see it, while I actually need the move back-to-indentation in between these checks.
In order to properly skip the last clause, I even have to set variable values.
(defun uncomment-mode-specific ()
"Uncomment region OR uncomment beginning of line comment OR uncomment end"
(interactive)
(let ((scvar 0) (scskipvar 0))
(save-excursion
(if (region-active-p)
(progn (uncomment-region (region-beginning) (region-end))
(setq scskipvar 1))
(back-to-indentation)) ; this is that "else" part that doesn't fit in cond
(while (string= (byte-to-string (following-char)) comment-start)
(delete-char 1)
(setq scskipvar 1))
(indent-for-tab-command)
(when (= scskipvar 0)
(search-forward comment-start nil t)
(backward-char 1)
(kill-line))
)))
)
So basically my question is, I would kind of like to have some consequences of not giving "true" to a clause, before the check of another clause. Is this possible? If not, what would be the best thing to do?
EDIT: Since we are using this as the example case for a solution, I wrote it down so it is easier to understand.
If region is active, remove comments from region. If not, move point to intendation.
For as long as the following character is a comment character, delete it. Afterwards, indent this line.
If it didn't do any of the above, search forward for a comment character, and kill that line.
(defun delete-on-this-line (regex)
(replace-regexp regex "" nil (line-beginning-position) (line-end-position)))
(defun delete-leading-comment-chars ()
(delete-on-this-line (eval `(rx bol (* space) (group (+ ,comment-start))))))
(defun delete-trailing-comment-chars ()
(delete-on-this-line (eval `(rx (group (+ ,comment-end)) (* space) eol))))
(defun delete-trailing-comment ()
(delete-on-this-line (eval `(rx (group (+ ,comment-start) (* anything) eol)))))
(defun uncomment-dwim ()
(interactive)
(save-excursion
(if (region-active-p)
(uncomment-region (region-beginning) (region-end))
(or (delete-leading-comment-chars)
(delete-trailing-comment-chars)
(delete-trailing-comment)))))
Edit: A little explanation:
It's a lot easier to do regex replacements than manage loops to do deletion, so that gets rid of the state. And the steps are all mutually exclusive, so you can just use or for each option.
The rx macro is a little DSL that compiles down to valid regexes, and it's also amenable to lispy syntax transforms, so I can dynamically build a regex using the comment chars for the current mode.
(defmacro fcond (&rest body)
(labels ((%substitute-last-or-fail
(new old seq)
(loop for elt on seq
nconc
(if (eql (car elt) old)
(when (cdr elt)
(error "`%S' must be the last experssion in the clause"
(car elt)))
(list new)
(list (car elt))))))
(loop with matched = (gensym)
with catcher = (gensym)
for (head . rest) in body
collect
`(when (or ,head ,matched)
(setq ,matched t)
,#(%substitute-last-or-fail `(throw ',catcher nil) 'return rest))
into clauses
finally
(return `(let (,matched) (catch ',catcher ,#clauses))))))
(macroexpand '(fcond
((= 1 2) (message "1 = 2"))
((= 1 1) (message "1 = 1"))
((= 1 3) (message "1 = 3") return)
((= 1 4) (message "1 = 4"))))
(let (G36434)
(catch (quote G36435)
(when (or (= 1 2) G36434)
(setq G36434 t)
(message "1 = 2"))
(when (or (= 1 1) G36434)
(setq G36434 t)
(message "1 = 1"))
(when (or (= 1 3) G36434)
(setq G36434 t)
(message "1 = 3")
(throw (quote G36435) nil))
(when (or (= 1 4) G36434)
(setq G36434 t)
(message "1 = 4"))))
Here's something quick to do, what I think you may be after, i.e. something that would mimic the behaviour switch in C.
The idea is that all clauses are tested sequentially for equality, and if one matches, then all following clauses are executed, until the return keyword (it would be break in C, but Lisp uses return for the similar purpose in the loop, so I thought that return would be better). The code above thus will print:
1 = 1
1 = 3
Technically, this is not how switch works in C, but it will produce the same effect.
One thing I did here for simplicity, which you want to avoid / solve differently - the use of return keyword, you probably want to impose stricter rules on how it should be searched for.
cond
Cond evaluates a series of conditions in a list, each item in a list can be a condition, and then executable instructions.
The example in the Emacs Lisp manual is adequate to demonstrate how it works, I've annotated it here to help you understand how it works.
(cond ((numberp x) x) ;; is x a number? return x
((stringp x) x) ;; is x a string? return x
((bufferp x) ;; is x a buffer?
(setq temporary-hack x) ;; set temporary-hack to buffer x
(buffer-name x)) ;; return the buffer-name for buffer x
((symbolp x) (symbol-value x))) ;; is x a symbol? return the value of x
Each part of the condition can be evaluated any way you like, the fact x above is in each condition is coincidental.
For example:
(cond ((eq 1 2) "Omg equality borked!") ;; Will never be true
(t "default")) ;; always true
So comparisons with switch are a bit limited, it's essentially a list of if statements, that executes/returns the first true condition's body list.
Hopefully this helps you understand cond a bit better.
(cond (condition body ... ) ;; execute body of 1st passing
(condition body ... ) ;; condition and return result
(condition body ... ) ;; of the final evaluation.
;; etc
)
OR
You can do things similar to switch with OR, depending on how you structure the code.
This isn't functional style, because it relies on side-effects to do what you want, then returns a boolean value for flow control, here's an example in pseudo lisp.
(or)
(or
(lambda() (do something)
(evaluate t or nil) ; nil to continue; t to quit.
)
(lambda() (do something)
(evaluate t or nil) ; nil to continue; t to quit.
)
(lambda() (do something)
(evaluate t or nil) ; nil to continue; t to quit.
)
(lambda() (do something)
(evaluate t or nil) ; nil to continue; t to quit.
)
)
Here's working example of a switch like structure using or
(or
(when (= 1 1)
(progn
(insert "hello\n")
nil))
(when (= 1 2) ;; condition fails.
(progn
(insert "hello\n")
nil)) ;; returns false (nil)
(when (= 1 1)
(progn
(insert "hello\n")
t)) ;; returns true, so we bail.
(when (= 1 1)
(progn
(insert "hello\n")
nil))
)
Inserts :
hello
hello
(and)
The and operator (not just in Lisp) is also very useful, instead of evaluating everything until true, it evaluates conditions that are true, until a false is evaluated.
Both or & and can be used to build useful logic trees.
This is how I did it now according to Chris' idea that breaking it down into seperate functions would make it easier.
EDIT: Now also applied the or knowledge gained in this thread gained from Slomojo (no more variables!)
(defun sc-uncomment ()
(interactive)
(or
(if (region-active-p)
(uncomment-region (region-beginning) (region-end))
(back-to-indentation)
nil)
(if (string= (byte-to-string (following-char)) comment-start)
(sc-check-start)
(sc-end))))
(defun sc-check-start ()
(interactive)
(while (string= (byte-to-string (following-char)) comment-start)
(delete-char 1))
)
(defun sc-end ()
(interactive)
(search-forward comment-start nil t)
(backward-char 1)
(kill-line))
)
An mplayer tool (midentify) outputs "shell-ready" lines intended to be evaluated by a bash/sh/whatever interpreter.
How can I assign these var-names to their corresponding values as elisp var-names in emacs?
The data is in a string (via shell-command-to-string)
Here is the data
ID_AUDIO_ID=0
ID_FILENAME=/home/axiom/abc.wav
ID_DEMUXER=audio
ID_AUDIO_FORMAT=1
ID_AUDIO_BITRATE=512000
ID_AUDIO_RATE=0
ID_AUDIO_NCH=1
ID_LENGTH=3207.00
ID_SEEKABLE=1
ID_CHAPTERS=0
ID_AUDIO_BITRATE=512000
ID_AUDIO_RATE=32000
ID_AUDIO_NCH=1
ID_AUDIO_CODEC=pcm
ID_EXIT=EOF
Here's a routine that takes a string containing midentify output, and returns an association list of the key-value pairs (which is safer than setting Emacs variables willy-nilly). It also has the advantage that it parses numeric values into actual numbers:
(require 'cl) ; for "loop"
(defun midentify-output-to-alist (str)
(setq str (replace-regexp-in-string "\n+" "\n" str))
(setq str (replace-regexp-in-string "\n+\\'" "" str))
(loop for index = 0 then (match-end 0)
while (string-match "^\\(?:\\([A-Z_]+\\)=\\(?:\\([0-9]+\\(?:\\.[0-9]+\\)?\\)\\|\\(.*\\)\\)\\|\\(.*\\)\\)\n?" str index)
if (match-string 4 str)
do (error "Invalid line: %s" (match-string 4 str))
collect (cons (match-string 1 str)
(if (match-string 2 str)
(string-to-number (match-string 2 str))
(match-string 3 str)))))
You'd use this function like so:
(setq alist (midentify-output-to-alist my-output))
(if (assoc "ID_LENGTH" alist)
(setq id-length (cdr (assoc "ID_LENGTH" alist)))
(error "Didn't find an ID_LENGTH!"))
EDIT: Modified function to handle blank lines and trailing newlines correctly.
The regexp is indeed a beast; Emacs regexps are not known for their easiness on the eyes. To break it down a bit:
The outermost pattern is ^(?:valid-line)|(.*). It tries to match a valid line, or else matches the entire line (the .*) in match-group 4. If (match-group 4 str) is not nil, that indicates that an invalid line was encountered, and an error is raised.
valid-line is (word)=(?:(number)|(.*)). If this matches, then the name part of the name-value pair is in match-string 1, and if the rest of the line matches a number, then the number is in match-string 2, otherwise the entire rest of the line is in match-string 3.
There's probably a better way but this should do it:
(require 'cl)
(let ((s "ID_AUDIO_ID=0
ID_FILENAME=/home/axiom/abc.wav
ID_DEMUXER=audio
ID_AUDIO_FORMAT=1
ID_AUDIO_BITRATE=512000
ID_AUDIO_RATE=0
ID_AUDIO_NCH=1
ID_LENGTH=3207.00
ID_SEEKABLE=1
ID_CHAPTERS=0
ID_AUDIO_BITRATE=512000
ID_AUDIO_RATE=32000
ID_AUDIO_NCH=1
ID_AUDIO_CODEC=pcm
ID_EXIT=EOF"))
(loop for p in (split-string s "\n")
do
(let* ((elements (split-string p "="))
(key (elt elements 0))
(value (elt elements 1)))
(set (intern key) value))))
Here's a function you can run on the output buffer:
(defun set-variables-from-shell-assignments ()
(goto-char (point-min))
(while (< (point) (point-max))
(and (looking-at "\\([A-Z_]+\\)=\\(.*\\)$")
(set (intern (match-string 1)) (match-string 2)))
(forward-line 1)))
I don't think regexp is what really need. You need to split your string by \n and =, so you just say exactly the same to interpreter.
I think you can also use intern to get symbol from string(and set variables). I use it for the first time, so comment here if i am wrong. Anyways, if list is what you want, just remove top-level mapcar.
(defun set=(str)
(mapcar (lambda(arg)
(set
(intern (car arg))
(cadr arg)))
(mapcar (lambda(arg)
(split-string arg "=" t))
(split-string
str
"\n" t))))
(set=
"ID_AUDIO_ID=0
ID_FILENAME=/home/axiom/abc.wav
ID_DEMUXER=audio
ID_AUDIO_FORMAT=1
ID_AUDIO_BITRATE=512000
ID_AUDIO_RATE=0
ID_AUDIO_NCH=1
ID_LENGTH=3207.00
ID_SEEKABLE=1
ID_CHAPTERS=0
ID_AUDIO_BITRATE=512000
ID_AUDIO_RATE=32000
ID_AUDIO_NCH=1
ID_AUDIO_CODEC=pcm
ID_EXIT=EOF")