On Tue, 15 Apr 2014 23:09:46 -0400
"David T. Pierson" wrote:
> On Tue, Apr 15, 2014 at 09:09:00PM +0200, Manfred Lotz wrote:
> > -> (count-substring "[\\[]" "a[rts[a3]")
> > 2
> > -> (count-substring "[a-z\\[]" "a[rts[a3]")
> > 7
> > -> (count-substring "[\\]]" "a[rts[a3]")
> > 0
> >
> > The fir
On Tue, Apr 15, 2014 at 09:09:00PM +0200, Manfred Lotz wrote:
> -> (count-substring "[\\[]" "a[rts[a3]")
> 2
> -> (count-substring "[a-z\\[]" "a[rts[a3]")
> 7
> -> (count-substring "[\\]]" "a[rts[a3]")
> 0
>
> The first two seem to work fine, the last one doesn't.
Those backslashes are not escapi
On Tue, 15 Apr 2014 21:39:24 +0200
Jens Axel Søgaard
wrote:
> If you need a literal ] you can use (regexp-quote "]")
>
> > (count-substring (regexp-quote "]") "a[rts[a3")
> 4
>
Didn't know this. It is not so bad. But I might want to match more than
one character.
For example the following
If you need a literal ] you can use (regexp-quote "]")
> (count-substring (regexp-quote "]") "a[rts[a3")
4
--
Jens Axel Søgaard
2014-04-15 21:09 GMT+02:00 Manfred Lotz :
> On Rosetta code in "Count occurrences of a substring" I found this for
> Racket:
>
> (define count-substring
> (com
I've taken to using `match` for this. Your example:
(regexp-match #rx"\"(.*)" "a\"b")
I would write as:
(match "a\"b"
[(regexp "\"(.*)" (list _ x)) x])
; "b"
Handling the no-match case by returning #f:
(match "ab"
[(regexp "\"(.*)" (list _ x)) x]
[_ #f])
; #f
Laurent's approach of defin
No, regexp-match is designed to return first the entire match followed by
the matched parenthesized expressions.
You can always write a wrapper that returns the parenthesized expressions
if you want:
#lang racket
(define (regexp-match-sub-matches rx str)
(cdr (or (regexp-match rx str) '(a . #f)
>
> ;This I understand:
> ;To return pattern and everything to left of first instance of pattern,
> use: [^]* ;where ^ means 'not'; example:
> (car (regexp-match* #rx"[^/]*/" "12/4/6")) ; => "12/"
>
A caveat for this. in the first instance isn't quite right. [...]
defines a single character. [abc
On May 8, 2013, at 11:54 AM, Eli Barzilay wrote:
> An hour ago, John Clements wrote:
>>
>> The traditional way to do this would be to match a sequence of
>> non-x's followed by an x, like this:
>>
>> #lang racket
>>
>> (regexp-match #rx"[^x]*x" "12x4x6") ; => '("12x")
>>
>> Things get a bit m
An hour ago, John Clements wrote:
>
> The traditional way to do this would be to match a sequence of
> non-x's followed by an x, like this:
>
> #lang racket
>
> (regexp-match #rx"[^x]*x" "12x4x6") ; => '("12x")
>
> Things get a bit more interesting if you put a more complex pattern
> in place o
Don, hello.
On 2013 May 8, at 18:25, Don Green wrote:
> (regexp-match #rx"___" "12x4x6") ; => '("12x") ;returns everything to left
> of first pattern x
Orthogonally to John's answer (which is all about matching the thing you want),
you can aim to match the pattern you want to terminate the th
On May 8, 2013, at 10:25 AM, Don Green wrote:
> Regexp question: Is there a pattern that can match everything to left of
> first pattern?
>
> (regexp-match #rx"x.*" "12x4x6") ; => '("x4x6") ;returns everything to right
> of first pattern x
>
> (regexp-match #rx"___" "12x4x6") ; => '("12x") ;r
On Tue, May 7, 2013 at 3:08 PM, Don Green wrote:
> Trying to use regexp-match to return a line containing a specified string...
>
>
> ;Create fn: find-string.ss.
>
> ;Given a file and a find-string.
>
> ;Returns a line-string with first find.
>
> ;The input file has a lot of lines.
In this case,
(regexp-match #rx"c\"d" "abc\"def")
and
(regexp-match #rx"c\\\"d" "abc\"def")
seems to work.
On Mon, 22 Oct 2012 16:30:15 +0200, Nadeem Abdul Hamid
wrote:
When I insert \\" in the pattern, the double quote is interpreted as the
end of the pattern.
You have to escape the quote too...
>
> When I insert \\" in the pattern, the double quote is interpreted as the
> end of the pattern.
>
You have to escape the quote too... " ... \\\" ... "
--- nadeem
Racket Users list:
http://lists.racket-lang.org/users
On 8/27/11 10:04 AM, Neil Van Dyke wrote:
#lang racket/base
(define str "17.4 25.4 15.7 13.7 19.4 20.9 ")
(regexp-split #rx"[ \t]+" str)
or with posix character class:
(regexp-split #px"[[:space:]]+" str)
_
For list-related administrative tasks:
I don't know about ":space:", but you can do regexp character classes
the old-fashioned way:
#lang racket/base
(define str "17.4 25.4 15.7 13.7 19.4 20.9 ")
(regexp-split #rx"[ \t]+" str)
;;==> '("17.4" "25.4" "15.7" "13.7" "19.4" "20.9" "")
I also used "regexp" instead
You could wrap the "\1" with the grouping operator "(?:...)":
> (regexp-match #px"(.*)\\1001" "abcabc001")
bad pregexp string: backreference number is larger than the
highest-numbered cluster
> (regexp-match #px"(.*)(?:\\1)001" "abcabc001")
'("abcabc001" "abc")
At Wed, 22 Jun 2011 09:52:09
The `port-commit-peeked' function (used by `regexp-match-evt') was
deeply broken with respect to `file-position' and `port-next-location'.
I see no workaround for old versions, but the problem is now fixed in
the current development version (in the git repo).
At Sat, 11 Jun 2011 07:19:03 -0700, Ma
Thanks for the report!
I think the bug is more specifically in the implementation of
`port-commit-peeked' for some kinds of ports, since the following
program also has the wrong result:
#lang racket/base
(define-values (in out) (make-pipe))
(display "12345" out)
(peek-bytes 3 0 in)
(port-com
You can use the primitive require, which is #%require IIRC.
HTH,
N.
On Sat, Feb 12, 2011 at 1:34 AM, geb a wrote:
> How do I use regexp with r5rs? I had some difficulty using outside of racket.
>
> Sincerely,
> Dan
>
>
>
> _
> For list-related ad
At Sat, 25 Dec 2010 10:23:54 -0500, Neil Van Dyke wrote:
> When doing a regexp on a character input port, what's the best way to
> get string results out instead of bytes results?
Decode the results of `regexp-match' using `bytes->string/utf-8'.
> For example, this is documented behavior, but no
Yesterday, Todd O'Bryan wrote:
> Is there some equivalent of regexp-match* that returns a list of all
> the (non-overlapping) matches in a string.
>
> I want something like:
>
> > (regexp-match*-clusters #px"(?:^|\\s+)([A-Z])" "This gets Initial CAPS, I
> > hope")
> '(("T" "T") (" I" "I") (" C"
I wrote the following function
(define/contract (regexp-match-all re str)
(regexp? string? . -> . (listof (listof (or/c string? #f
(map (λ (s) (regexp-match re s))
(regexp-match* re str)))
I don't know if it would be worth including among the standard regexp operators.
Todd
On Sa
15 minutes ago, YC wrote:
> On Tue, Dec 7, 2010 at 12:25 AM, Eli Barzilay wrote:
> >
> > Actually, there's a problem -- there is already an optional
> > argument for the prefix, and if an output port is added, it should
> > be added before that for consistency but that will be
> > incompatible.
>
On Tue, Dec 7, 2010 at 12:25 AM, Eli Barzilay wrote:
>
> Actually, there's a problem -- there is already an optional argument
> for the prefix, and if an output port is added, it should be added
> before that for consistency but that will be incompatible.
That's unfortunate. Looking at v4.2.5 I
10 minutes ago, YC wrote:
> On Mon, Dec 6, 2010 at 11:49 PM, Eli Barzilay wrote:
>
> > Well, that would be an obvious issue... It might be possible to
> > do this if they're extended to get an output port too, something
> > like:
> >
> > (regexp-replace* #rx"foo" inp "bar" outp)
> >
> > doing t
On Mon, Dec 6, 2010 at 11:49 PM, Eli Barzilay wrote:
>
> Well, that would be an obvious issue... It might be possible to do
> this if they're extended to get an output port too, something like:
>
> (regexp-replace* #rx"foo" inp "bar" outp)
>
> doing the same thing as the loop that I wrote.
So
The change was not intentional, and I'll fix it soon.
Thanks for the report!
At Sat, 26 Jun 2010 15:38:49 -0700, synx wrote:
>
> Okay what. I've long relied on the behavior of regexp-replace* to single
> out a number of substrings within a big string, and let me mangle those
> substrings in a pr
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