I want to write a function that deletes all vowels from a string. I thought of defining a function that detects the vowels, something similar to symbolp, zerop and so on and if it is a vowel, delete it. How can I do this? I would appreciate any input on this. Thanks
(defun deletevowels (string)
(go through the list
(if vowel-p deletevowels )
)
)
Nevertheless, I have the problem that deletes a vowel if it's the last, how can I modify this to meet what I want to do, to delete all vowels in a string? In the code below there's this function I was mentioning, vowel-p one.
(defun strip-vowel (word)
"Strip off a trailing vowel from a string."
(let* ((str (string word))
(end (- (length str) 1)))
(if (vowel-p (char str end))
(subseq str 0 end)
str)))
(defun vowel-p (char) (find char "aeiou" :test #'char-equal))
Moreover, is it easier if I would use the function below to turn the string into a list and then loop in the list instead of the string to look for the vowel and remove it?
(defun string-to-list (string)
(loop for char across string collect char))
CL-USER 27 > (defun vowel-p (char)
(find char "aeiou" :test #'char-equal))
VOWEL-P
CL-USER 28 > (remove-if #'vowel-p "abcdef")
"bcdf"
See: Common Lisp Hyperspec, REMOVE-IF.
CL-USER 29 > (defun deletevowels (string)
(remove-if #'vowel-p string))
DELETEVOWELS
CL-USER 30 > (deletevowels "spectacular")
"spctclr"
I'm trying to take user input and storing it in a list, only instead of a list consisting of a single string, I want each word scanned in to be its own string.
Example:
> (input)
This is my input. Hopefully this works
would return:
("this" "is" "my" "input" "hopefully" "this" "works")
Taking note that I don't want any spaces or punctuation in my final list.
Any input would be greatly appreciated.
split-sequence is the off-the-shelf solution.
you can also roll your own:
(defun my-split (string &key (delimiterp #'delimiterp))
(loop :for beg = (position-if-not delimiterp string)
:then (position-if-not delimiterp string :start (1+ end))
:for end = (and beg (position-if delimiterp string :start beg))
:when beg :collect (subseq string beg end)
:while end))
where delimiterp checks whether you want to split on this character, e.g.
(defun delimiterp (c) (or (char= c #\Space) (char= c #\,)))
or
(defun delimiterp (c) (position c " ,.;/"))
PS. looking at your expected return value, you seem to want to call string-downcase before my-split.
PPS. you can easily modify my-split to accept :start, :end, :delimiterp &c.
PPPS. Sorry about bugs in the first two versions of my-split. Please consider that an indicator that one should not roll one's own version of this function, but use the off-the-shelf solution.
For that task in Common-Lisp I found useful (uiop:split-string str :separator " ") and the package uiop, in general, has a lot of utilities, take a look at the docs https://common-lisp.net/project/asdf/uiop.html#index-split_002dstring.
There's cl-ppcre:split:
* (split "\\s+" "foo bar baz
frob")
("foo" "bar" "baz" "frob")
* (split "\\s*" "foo bar baz")
("f" "o" "o" "b" "a" "r" "b" "a" "z")
* (split "(\\s+)" "foo bar baz")
("foo" "bar" "baz")
* (split "(\\s+)" "foo bar baz" :with-registers-p t)
("foo" " " "bar" " " "baz")
* (split "(\\s)(\\s*)" "foo bar baz" :with-registers-p t)
("foo" " " "" "bar" " " " " "baz")
* (split "(,)|(;)" "foo,bar;baz" :with-registers-p t)
("foo" "," NIL "bar" NIL ";" "baz")
* (split "(,)|(;)" "foo,bar;baz" :with-registers-p t :omit-unmatched-p t)
("foo" "," "bar" ";" "baz")
* (split ":" "a:b:c:d:e:f:g::")
("a" "b" "c" "d" "e" "f" "g")
* (split ":" "a:b:c:d:e:f:g::" :limit 1)
("a:b:c:d:e:f:g::")
* (split ":" "a:b:c:d:e:f:g::" :limit 2)
("a" "b:c:d:e:f:g::")
* (split ":" "a:b:c:d:e:f:g::" :limit 3)
("a" "b" "c:d:e:f:g::")
* (split ":" "a:b:c:d:e:f:g::" :limit 1000)
("a" "b" "c" "d" "e" "f" "g" "" "")
http://weitz.de/cl-ppcre/#split
For common cases there is the (new, "modern and consistent") cl-str string manipulation library:
(str:words "a sentence with spaces") ; cut with spaces, returns words
(str:replace-all "," "sentence") ; to easily replace characters, and not treat them as regexps (cl-ppcr treats them as regexps)
You have cl-slug to remove non-ascii characters and also punctuation:
(asciify "Eu André!") ; => "Eu Andre!"
as well as str:remove-punctuation (that uses cl-change-case:no-case).
; in AutoLisp usage (splitStr "get off of my cloud" " ") returns (get off of my cloud)
(defun splitStr (src delim / word letter)
(setq wordlist (list))
(setq cnt 1)
(while (<= cnt (strlen src))
(setq word "")
(setq letter (substr src cnt 1))
(while (and (/= letter delim) (<= cnt (strlen src)) ) ; endless loop if hits NUL
(setq word (strcat word letter))
(setq cnt (+ cnt 1))
(setq letter (substr src cnt 1))
) ; while
(setq cnt (+ cnt 1))
(setq wordlist (append wordlist (list word)))
)
(princ wordlist)
(princ)
) ;defun
(defun splitStr (src pat /)
(setq wordlist (list))
(setq len (strlen pat))
(setq cnt 0)
(setq letter cnt)
(while (setq cnt (vl-string-search pat src letter))
(setq word (substr src (1+ letter) (- cnt letter)))
(setq letter (+ cnt len))
(setq wordlist (append wordlist (list word)))
)
(setq wordlist (append wordlist (list (substr src (1+ letter)))))
)
In Emacs or Vim, what's a smooth way to join strings as in this example:
Transform from:
(alpha, beta, gamma) blah (123, 456, 789)
To:
(alpha=123, beta=456, gamma=789)
It would need to scale to:
many lines of these
many elements in the parentheses
I have recently found myself needing this kind of transformation often.
I use Evil in Emacs which is why a Vim answer would likely also help.
UPDATE:
The solutions were not as general as I had hoped. For example, I'd like the solution to also work when I have a list of strings and wish to distribute them into a large XML document. eg:
<item foo="" bar="barval1"/>
<item foo="" bar="barval2"/>
<item foo="" bar="barval3"/>
<item foo="" bar="barval4"/>
fooval1
fooval2
fooval3
fooval4
I formulated a solution and have added it as an answer.
%s/(\(\S\{-}\), \(\S\{-}\), \(\S\{-}\)).\{-}(\(\S\{-}\), \(\S\{-}\), \(\S\{-}\))/(\1=\4, \2=\5, \3=\6)
%s: global search and replace
\(\S{-}\),: non greedy search for non-whitespace characters up to the next comma, enclosed by "(" for backreferencing
\1=\4 : prints out the first match, an "=" sign, then the fourth match
for such text transformation, I would go with awk:
this one-liner may help:
awk -F'\\(|\\)' '{split($2,t,",");split($4,v,",");printf "( "; for(x in t)s=s""sprintf("%s=%s, ", t[x],v[x]);sub(", $","",s);printf s")\n";s=""}' file
little test:
kent$ cat test
(alpha, beta, gamma) blah (123, 456, 789)
(a, b, c) foo (1, 2, 3)
(x, y, z, m, n) bar (100, 200, 300, 400, 500)
kent$ awk -F'\\(|\\)' '{split($2,t,",");split($4,v,",");printf "( "; for(x in t)s=s""sprintf("%s=%s, ", t[x],v[x]);sub(", $","",s);printf s")\n";s=""}' test
( alpha=123, beta= 456, gamma= 789)
( a=1, b= 2, c= 3)
( m= 400, n= 500, x=100, y= 200, z= 300)
Emacs Lisp version of Prince Goulash answer
(require 'cl)
(defun split-and-trim (str separator)
(let ((strs (split-string str separator)))
(mapcar (lambda (s)
(replace-regexp-in-string "^\\s-+" "" s))
(mapcar (lambda (s)
(replace-regexp-in-string "\\s-$" "" s)) strs))))
(defun my/merge-list (beg end)
(interactive "r")
(goto-char beg)
(let ((endmark (set-mark end))
(regexp "(\\([^)]+\\))[^(]+(\\([^)]+\\))"))
(while (re-search-forward regexp end t)
(let ((replace-start (match-beginning 0))
(replace-end (match-end 0))
(keys-str (match-string-no-properties 1))
(values-str (match-string-no-properties 2)))
(let* ((keys (split-and-trim keys-str ","))
(values (split-and-trim values-str ",")))
(while (> (length keys) (length values))
(setq values (append values '(""))))
(let* ((pairs (mapcar* (lambda (k v)
(format "%s=%s" k v)) keys values))
(transformed (format "(%s)" (mapconcat #'identity pairs ", "))))
(goto-char replace-start)
(delete-region replace-start replace-end)
(insert transformed)))))
(goto-char (marker-position endmark))))
For example, you select region as following
(alpha, beta, gamma) blah (123, 456, 789)
(alpha, beta, gamma, delta) blah (123, 456, 789, aaa)
After M-x my/merge-list
(alpha=123, beta=456, gamma=789)
(alpha=123, beta=456, gamma=789, delta=aaa)
This method I'm going to describe is a bit wacky, but it involves the minimum amount of Elisp code I could manage. It's only applicable if the lists to be joined can be interpreted as Lisp lists once the commas in them are removed. Numbers and sequences of alphabetic characters, as in your example, would be fine.
First, make sure that the Common Lisp library is loaded: M-:(require 'cl)RET.
Now, starting with the cursor at the start of the first list:
M-C-k ; kill-forward-sexp
C-e ; move-end-of-line
M-C-b ; backward-sexp
M-C-k ; kill-forward-sexp
C-a ; move-beginning-of-line
C-k ; kill-line
Now blah (or whatever) is the first entry in the kill ring, the second list is the second entry, and the first list is the third entry.
Type (, then M-: (eval-expression), take a deep breath, and type this:
(loop with (a b) = (mapcar (lambda (x) (car (read-from-string (remove ?, x))))
(subseq kill-ring 1 3))
for x in a for y in b do (insert (format "%s=%s, " y x)))
(I've broken it up for presentation purposes, but you can type it all on one line.)
Then finally DELDEL), and you're done! You could turn it into a macro, if you wanted.
Here is a Vimscript solution. It is nowhere near as elegant as ash's answer, but it works with lists of any length.
function! ListMerge()
" Get line, remove text between lists, split lists at parentheses:
let curline = getline('.')
let curline = substitute(curline,')\zs.*\ze(','','g')
let curline = substitute(curline,'(','','g')
let lists = map(split(curline,')'),'split(v:val,",")')
" Return if we don't have two lists of equal length:
if len(lists) != 2 || len(lists[0]) != len(lists[1])
return
endif
" Loop over the lists, remove whitespace, build the replacement string:
let i=0
let string = '('
while i<len(lists[0])
let string .= substitute(lists[0][i],'^ *','','')
let string .= '='
let string .= substitute(lists[1][i],'^ *','','')
let string .= ', '
let i+=1
endwhile
" Add the concluding bracket:
let string = substitute(string,', $',')','')
" Replace the current line with the string:
execute "normal! S" . string
endfunction
You can then call this function on all lines like this:
:%call ListMerge()
My approach is to create one command to set a match-list, then use replace-regexp as the second command to distribute match-list, leveraging replace-regexp's existing \, facility.
Evaluate Elisp, such as in the .emacs file:
(defvar match-list nil
"A list of matches, as set through the set-match-list and consumed by the cycle-match-list function. ")
(defvar match-list-iter nil
"Iterator through the global match-list variable. ")
(defun reset-match-list-iter ()
"Set match-list-iter to the beginning of match-list and return it. "
(interactive)
(setq match-list-iter match-list))
(defun make-match-list (match-regexp use-regexp beg end)
"Set the match-list variable as described in the documentation for set-match-list. "
;; Starts at the beginning of region, searches forward and builds match-list.
;; For efficiency, matches are appended to the front of match-list and then reversed
;; at the end.
;;
;; Note that the behavior of re-search-backward is such that the same match-list
;; is not created by starting at the end of the region and searching backward.
(let ((match-list nil))
(save-excursion
(goto-char beg)
(while
(let ((old-pos (point)) (new-pos (re-search-forward match-regexp end t)))
(when (equal old-pos new-pos)
(error "re-search-forward makes no progress. old-pos=%s new-pos=%s end=%s match-regexp=%s"
old-pos new-pos end match-regexp))
new-pos)
(setq match-list
(cons (replace-regexp-in-string match-regexp
use-regexp
(match-string 0)
t)
match-list)))
(setq match-list (nreverse match-list)))))
(defun set-match-list (match-regexp use-regexp beg end)
"Set the match-list global variable to a list of regexp matches. MATCH-REGEXP
is used to find matches in the region from BEG to END, and USE-REGEXP is the
regexp to place in the match-list variable.
For example, if the region contains the text: {alpha,beta,gamma}
and MATCH-REGEXP is: \\([a-z]+\\),
and USE-REGEXP is: \\1
then match-list will become the list of strings: (\"alpha\" \"beta\")"
(interactive "sMatch regexp: \nsPlace in match-list: \nr")
(setq match-list (make-match-list match-regexp use-regexp beg end))
(reset-match-list-iter))
(defun cycle-match-list (&optional after-end-string)
"Return the next element of match-list.
If AFTER-END-STRING is nil, cycle back to the beginning of match-list.
Else return AFTER-END-STRING once the end of match-list is reached."
(let ((ret-elm (car match-list-iter)))
(unless ret-elm
(if after-end-string
(setq ret-elm after-end-string)
(reset-match-list-iter)
(setq ret-elm (car match-list-iter))))
(setq match-list-iter (cdr match-list-iter))
ret-elm))
(defadvice replace-regexp (before my-advice-replace-regexp activate)
"Advise replace-regexp to support match-list functionality. "
(reset-match-list-iter))
Then to solve the original problem:
M-x set-match-list
Match regexp: \([0-9]+\)[,)]
Place in match-list: \1
M-x replace-regexp
Replace regexp: \([a-z]+\)\([,)]\)
Replace regexp with: \1=\,(cycle-match-list)\2
And to solve the XML example:
[Select fooval strings.]
M-x set-match-list
Match regexp: .+
Place in match-list: \&
[Select XML tags.]
M-x replace-regexp
Replace regexp: foo=""
Replace regexp with: foo="\,(cycle-match-list)"
Given that:
(define output "")
or that
(define output "goodInput")
When I run those defines in my code, I get:
ERROR: In procedure memoization:
ERROR: Bad define placement (define output "").
Why is that ?
EDIT:
; Formal function of the code
(define (double->sum myString)
(define myVector 0)
(set! myVector (breaking myString))
(define output "")
(define returnValue (checkLegit myVector)) ; check the number of legitimate characters ,they need to be either numbers or "."
(define flag 0)
(if (not(= returnValue (vector-length myVector))) (set! output "Input error") (set! flag (+ flag 1)))
(define i 0) ; the length of the vector
(define count 0) ; the value of all the numbers in the vector
(if
(= flag 1)
(do ()
((= i (vector-length myVector))) ; run until the end of the vector
(cond
((char=? (vector-ref myVector i) #\.) ; check if we found a dot
(set! output (appending output count)) (set! output (appendingStrings output ".")) (set! count 0)
)
(else (set! count (+ count (char->integer(vector-ref myVector i)) )) (set! count (- count 48))
); end of else
) ; end of cond
(set! i (+ i 1)) ; inc "i" by 1
); end of do
) ; end do
; if flag = 1 , then the input is in a correct form
(if (= flag 1) (set! output (appending output count)))
(if (= flag 1)
output
"Input error")
) ; END
The problem is not in the string definition itself (there are no strange characters, or anything like that), it's in the place within the code where that definition is happening: you're inside a procedure, and the last line in a procedure can not be a define. Try returning something after the definition and it should work fine.
I guess that you've just started writing the procedure, just keep going after the define and write the rest of the code. For the time being, use a placeholder value at the end, so the interpreter won't complain:
(define (double->sum myString)
(define myVector 0)
(set! myVector (breaking myString))
(define output "")
'ok)
Also a matter of style - although it's ok to define-and-set a variable like that, it's more idiomatic to use a let expression for defining local variables. This is what I mean:
(define (double->sum myString)
(let ((myVector (breaking myString))
(output ""))
'ok))
In that way, you won't have to use set!, which mutates the variable and goes against the functional-programming style preferred in Scheme.