Re: [racket-users] a minor regexp question (and a how-could-I-answer-it-myself? question)
Thanks, Jens, much appreciated. I suspect I even knew this once and had since forgotten it. (I even glanced at the docs, saw the two kinds, but didn’t pause long enough to wonder if it mattered to me.) -- You received this message because you are subscribed to the Google Groups "Racket Users" group. To unsubscribe from this group and stop receiving emails from it, send an email to racket-users+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/racket-users/69320674-8272-4751-a6ce-40c140a7358c%40googlegroups.com.
[racket-users] a minor regexp question (and a how-could-I-answer-it-myself? question)
hi, just now I'm debugging a regular expression and trying to understand why
this:
> (regexp-match-positions #rx"[-+][0-9]+" "-0500")
'((0 . 5))
works as I expect, whereas this:
> (regexp-match-positions #rx"[-+][0-9]{4}" "-0500")
#f
doesn't. (My naive opinion is the second expression should return the same
answer as the first.)
Wondering whether I could discover for myself whether this is a known issue, I
found directly:
https://github.com/racket/racket/search?q=regexp=Issues
or perhaps something like this:
https://github.com/racket/racket/search?q=regexp+type%3Aissue_q=regexp+type%3Aissue
is better, but either way I'm quickly pretty lost in terms of deciding whether
this relates to a known issue.
I'd appreciate advice on either question.
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Re: [racket-users] a question or two regarding Gregor
very helpful that you linked to the issue, thank you. I now understand there are non-trivial problem domain issues (for example, “CDT” is ambiguous, probably even with locale specified.) I will think about how to tackle my specific problem and whether I can help with issues like these. -- You received this message because you are subscribed to the Google Groups "Racket Users" group. To unsubscribe from this group and stop receiving emails from it, send an email to racket-users+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/racket-users/3cdc53af-be4f-48c3-9901-72b15751023d%40googlegroups.com.
Re: [racket-users] a question or two regarding Gregor
Thanks for the quick reply, Jon! OK, good to know. Maybe I can add the ones I need (if I can figure out how...). :) -- You received this message because you are subscribed to the Google Groups "Racket Users" group. To unsubscribe from this group and stop receiving emails from it, send an email to racket-users+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/racket-users/71a39eaa-7714-47fb-9d24-0d151ae93060%40googlegroups.com.
Re: [racket-users] a question or two regarding Gregor
p.s. I'm stuck on parsing one pattern that comes up in my data. Here's a corresponding test: (parameterize ([current-locale "en"]) (check-equal? (parse-datetime "Sun, 21 Jun 2015 17:50:44 -0500 (CDT)" "EEE, dd MMM HH:mm:ss ()") (datetime 2015 6 21 17 50 44))) that fails with ../../../../../Library/Racket/7.6/pkgs/gregor-lib/gregor/private/pattern/ast/zone.rkt:40:2: match: no matching clause for (Zone ... 'offset-name 'long) I'm looking at the source code but am not quite sure. Are zone descriptors such as CDT supported? (I also tried (zzz), but it also fails with no matching clause for (Zone ... 'offset-name 'short).) In https://unicode.org/reports/tr35/tr35-dates.html#Date_Format_Patterns I find an example: Pattern Result (in a particular locale) .MM.dd G 'at' HH:mm:ss zzz 1996.07.10 AD at 15:08:56 PDT which makes me think it should perhaps work. -- You received this message because you are subscribed to the Google Groups "Racket Users" group. To unsubscribe from this group and stop receiving emails from it, send an email to racket-users+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/racket-users/10f6f25d-6da8-4bbb-9459-ce63ae071c34%40googlegroups.com.
Re: [racket-users] a question or two regarding Gregor
Thanks, Jon! I agree with your analysis and thoughts about which cases should always raise exceptions. (I can't recall whether you scan patterns that include semi-redundant information such as day-of-week; wondered just now whether a contradictory day of week would be another category of exception -- or whether you just ignore it.) I guess I will try an approach like the one Ben posted for now, just to find out how many patterns turn up. Later I'd be interested in an elegant way to pre-test "parse-ability", though I have a healthy respect for the effort involved. (And you've done a great job, I think, of keeping just what is needed and hiding lots of details in the "private" sections. One doesn't want to add more than is needed.) -- You received this message because you are subscribed to the Google Groups "Racket Users" group. To unsubscribe from this group and stop receiving emails from it, send an email to racket-users+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/racket-users/b3120b5f-1c5b-4e34-b342-6cd12ef27aba%40googlegroups.com.
Re: [racket-users] a question or two regarding Gregor
Thanks. Something like that will let me proceed for now. I'd still be curious what folks think about an approach avoiding exceptions. -- You received this message because you are subscribed to the Google Groups "Racket Users" group. To unsubscribe from this group and stop receiving emails from it, send an email to racket-users+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/racket-users/7bf167d1-b96d-42ba-9c53-5401e811eed9%40googlegroups.com.
[racket-users] a question or two regarding Gregor
hi, I've installed and am trying out Gregor: a date and time library for Racket and find it to be very powerful and useful. In my current application (digging through mail headers) I'm wondering whether there is a way to test whether a given date-time format matches without using exceptions. (I assume that would generally be more efficient than catching exceptions.) I've forked https://github.com/97jaz/gregor and successfully added a couple of tests that work to tests/parse.rkt: (test-suite "some datetime particulars" (check-equal? (parse-datetime "2015-03-15T02:02:02-04:00" "-MM-dd'T'HH:mm:ssxxx") (datetime 2015 3 15 2 2 2)) (parameterize ([current-locale "en"]) (check-equal? (parse-datetime "21 Jun 2015 15:45:40" "dd MMM HH:mm:ss") (datetime 2015 6 21 15 45 40))) (check-exn exn:gregor:parse? (lambda () (parse-datetime "21 Jun 2015 15:45:40 -" "-MM-dd'T'HH:mm:ssxxx"))) ) I'd like to add something along these lines: (check-equal? (parsable-as-datetime? "2015-03-15T02:02:02-04:00" "-MM-dd'T'HH:mm:ssxxx") #t) (check-equal? (parsable-as-datetime?"21 Jun 2015 15:45:40 -" "-MM-dd'T'HH:mm:ssxxx") #f) but implementing them would take me longer than I have at the moment. (Maybe using an err lambda that doesn't throw an exception?) I thought I'd check here: - does this seem like a reasonable idea? - is mine an unusual use case and most folks know what format to expect and the exception approach is fine? - is there perhaps an elegant way for me to test with a regular expression first rather than adding this function to Gregor? Cheers, Tim -- You received this message because you are subscribed to the Google Groups "Racket Users" group. To unsubscribe from this group and stop receiving emails from it, send an email to racket-users+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/racket-users/64c02e43-f693-475b-a8f4-05cf8f622c25%40googlegroups.com.
Re: [racket-users] question re downloading a PDF file
Thanks, Dominik, that appears to do the trick! (pdfgrep is immediately happy...). Much appreciated, Tim -- You received this message because you are subscribed to the Google Groups "Racket Users" group. To unsubscribe from this group and stop receiving emails from it, send an email to racket-users+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/racket-users/b117ca57-d32f-44ba-a1fb-1185a23e3442%40googlegroups.com.
[racket-users] question re downloading a PDF file
hi,
I need to fetch a number of PDF documents and wrote a bit of racket to make it
easier. The part that "downloads" is this:
(let ([content
((compose port->string get-pure-port string->url) (url-for-doc year
doc-name))])
(let ([out (open-output-file full-path-of-file-to-write #:mode 'text)])
(write-string content out)
(close-output-port out)
According to the file utility the resulting file is a
PDF document, version 1.7
But I can't open it with preview on a mac ("it may be damaged or use a format
that preview doesn't recognize"); pdfgrep ("cannot open") and pdf2ps (
Error: An error occurred while reading an XREF table.
The file has been damaged. This may have been caused
by a problem while converting or transfering the file.
) also complain.
Using mac file system info (command i) I notice differences when I examine a
file downloaded this way versus one I got using save-as with a browser. The
file I download with racket shows nothing in the "More info" section. The
version downloaded with a browser shows about 10 fields. Is there something
outside the file I need to worry about? (Once upon a time mac files had data
and resource forks -- maybe they still do?)
Should I be using some other method of downloading? (Incidentally I also tried
#:mode 'binary.)
Might I have more luck under gnu linux?
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[racket-users] macOSX trick linking drracket in dock to current version via /etc/paths.d/racket ?
hi, I just upgraded to 7.4 and rediscovered (here, thanks for helpful posts!) the best practice for the bash $PATH using /etc/paths.d/racket. Is there an analogous trick to "update" which version I get when I click on the drracket icon in the macOSX dock? (OK, it's only a few clicks to remove it and re-add it from /Applications/...7.4/bin/drracket ...). I also searched roughly "programmatically add adjust macOSX dock icon" but nothing conclusive popped out at me. Sincerely, Lazy but Curious :) -- You received this message because you are subscribed to the Google Groups "Racket Users" group. To unsubscribe from this group and stop receiving emails from it, send an email to racket-users+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/racket-users/aa70ee6f-1f38-4829-a1f4-02d8a40441bf%40googlegroups.com.
Re: [racket-users] go cheney yourself
Sorry! Yes, wrong list; noticed immediately; deleted immediately, butI guess that doesn’t stop the mails. Mea maxima culpa. I’ll try to be more careful in the future. Tim > On Jan 8, 2019, at 10:37 PM, Matthias Felleisen > wrote: > > > This is totally inappropriate. > > >> On Jan 8, 2019, at 4:09 PM, Tim Hanson wrote: >> >> great piece by Michelle Goldberg, imho: >> >> https://www.nytimes.com/2019/01/07/opinion/rashida-tlaib-profanity.html >> >> -- >> You received this message because you are subscribed to the Google Groups >> "Racket Users" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to racket-users+unsubscr...@googlegroups.com. >> For more options, visit https://groups.google.com/d/optout. > -- You received this message because you are subscribed to the Google Groups "Racket Users" group. To unsubscribe from this group and stop receiving emails from it, send an email to racket-users+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
[racket-users] go cheney yourself
great piece by Michelle Goldberg, imho: https://www.nytimes.com/2019/01/07/opinion/rashida-tlaib-profanity.html -- You received this message because you are subscribed to the Google Groups "Racket Users" group. To unsubscribe from this group and stop receiving emails from it, send an email to racket-users+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
Re: [racket-users] a matrix question
Many thanks, Jens Axel! That looks very good and includes several techniques that will help and inspire me, in particular for*/matrix, which I hadn't used yet. I'll try it out the next chance I get. -- You received this message because you are subscribed to the Google Groups "Racket Users" group. To unsubscribe from this group and stop receiving emails from it, send an email to racket-users+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
[racket-users] a matrix question
hi, I'm trying out matrices (without typed racket, though I read the performance caveat -- I'm not worried about performance at the moment) and am trying to find the best idioms for a small function I'd like to build. Q1: is there an elegant away to assemble a matrix column-wise? (my first draft solution is to read one col-matrix and write cell by cell into a destination (mutable) matrix); my preference would be to use immutable items, but that's secondary to elegance at this point. cheers, Tim -- You received this message because you are subscribed to the Google Groups "Racket Users" group. To unsubscribe from this group and stop receiving emails from it, send an email to racket-users+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
Re: [racket-users] "Site not secure"
Thanks for fixing it! -- You received this message because you are subscribed to the Google Groups "Racket Users" group. To unsubscribe from this group and stop receiving emails from it, send an email to racket-users+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
[racket-users] "Site not secure"
Hi, I tried to grab the latest racket version from download.racket-lang.org and chrome and edge tell me the certificate of the site at mirror.racket-lang.org is not yet valid or expired. It's no problem as I found a mirror with a valid certificate, but I guess you'll want to renew the certificate. Cheers, tim -- You received this message because you are subscribed to the Google Groups "Racket Users" group. To unsubscribe from this group and stop receiving emails from it, send an email to racket-users+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
Re: [racket-users] catching a contract violation in a unit test with check-exn
Thanks again. I've tweaked and commented the end of Mathias's example: (module+ test (check-exn exn:fail:contract? (lambda () (f 1))) ; violates contract by returning non-integer (check-exn exn:fail:contract? (lambda () (f 'a ; violates contract by being called with a non-integer and "thunking" makes my example work as I wanted: (check-exn exn:fail:contract? (lambda () (stream-first (pairwise-stream (stream-cons 1 empty-stream) -- You received this message because you are subscribed to the Google Groups "Racket Users" group. To unsubscribe from this group and stop receiving emails from it, send an email to racket-users+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
Re: [racket-users] catching a contract violation in a unit test with check-exn
Beautiful! Thanks to both of you. Can't wait to try it out. Cheers, Tim -- You received this message because you are subscribed to the Google Groups "Racket Users" group. To unsubscribe from this group and stop receiving emails from it, send an email to racket-users+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
[racket-users] catching a contract violation in a unit test with check-exn
Hi, I guess this didn't find the right subject matter expert yet. Would it be better to ask a specific person or use a different channel? Cheers, tbh -- You received this message because you are subscribed to the Google Groups "Racket Users" group. To unsubscribe from this group and stop receiving emails from it, send an email to racket-users+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
[racket-users] catching a contract violation in a unit test with check-exn
hi, As part of something I'm working on I want to convert a stream of values into a stream of pairs of values, e.g. 1 2 3 4 becomes (1 2) (3 4) The following seems to work fine: (define (pairwise-stream astream) (if (stream-empty? astream) empty-stream (stream-cons (cons (stream-first astream) (stream-first (stream-rest astream))) (pairwise-stream (stream-rest (stream-rest astream)) but I'd like my 2nd or 3rd test to detect a problem with a stream of odd length and haven't figured out how yet. Here's my attempt (lengths 0 and 2 work fine, length 1 shows a contract violation, but my test doesn't detect it): (check-equal? (stream->list (pairwise-stream empty-stream)) (stream->list empty-stream)) ; hmmm, how to detect this correctly? ;(check-exn ; exn:fail:contract? ; (stream-first ; (pairwise-stream (stream-cons 1 empty-stream (check-equal? (stream->list (pairwise-stream (stream-cons 1 (stream-cons 2 empty-stream (stream->list (stream-cons (cons 1 2) empty-stream))) I'd be grateful for advice. Cheers, Tim -- You received this message because you are subscribed to the Google Groups "Racket Users" group. To unsubscribe from this group and stop receiving emails from it, send an email to racket-users+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
Re: [racket-users] Hint on opening enclosing directory of current file from DrRacket
Heh, cool, Laurent! This dabbler had missed this until now -- I will read and probably use. Cheers, tim -- You received this message because you are subscribed to the Google Groups "Racket Users" group. To unsubscribe from this group and stop receiving emails from it, send an email to racket-users+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
Re: [racket-users] [Racket-users] IMAP with racket
p.s. I just found this: https://planet.racket-lang.org/package-source/gh/gapi.plt/1/3/planet-docs/manual/Examples.html which leads here: https://github.com/greghendershott/gapi/blob/master/examples/macro/gplus-oauth.rkt and looks promising. (I didn't find any signs of oauth use in sirmail (or for that matter in racket on github, but I probably don't know where to look)). I found this: https://pkgs.racket-lang.org/#(!deprecated)(!main-distribution)(!main-tests)(oauth) Why does google rely on / require a thing which is an emerging standard and still unstable? -- You received this message because you are subscribed to the Google Groups "Racket Users" group. To unsubscribe from this group and stop receiving emails from it, send an email to racket-users+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
Re: [racket-users] [Racket-users] IMAP with racket
Bravo! This parallels my motivation. I'm kind of a beginner in Racket, but it is powerful, portable, elegant, well-documented, and well-supported, so I keep dabbling ... -- You received this message because you are subscribed to the Google Groups "Racket Users" group. To unsubscribe from this group and stop receiving emails from it, send an email to racket-users+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
Re: [racket-users] IMAP with racket
Thanks, all, this rings a bell and I note that: https://docs.racket-lang.org/webapi/oauth2.html says use with caution. I will look around and see if I can figure out how to do imap in conjunction with oauth2. Cheers, Tim -- You received this message because you are subscribed to the Google Groups "Racket Users" group. To unsubscribe from this group and stop receiving emails from it, send an email to racket-users+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
Re: [racket-users] IMAP with racket
Thanks again for several helpful pointers. I've recorded humble beginnings here: https://github.com/tbhanson/imap-with-racket Comments and suggestions very welcome. (I know in particular I'd like to have a handy way to store my credentials somewhere, am using ~/.myImapCreds for now, but am unsure whether to keep server connection details in the same place or a kind of parallel place.) I have successfully connected to two of the mail servers I use this way, but not yet to gmail. Has anyone successfully connected to gmail using either of the approaches tested here? Maybe someone can point out what I'm doing wrong? (I remember gmail was finicky a while back when I tried connecting to it using Thunderbird; at some point it broke, with google warning some insecure app was trying to access my mail (same thing happens with my racket attempts so far). I was later able to connect after sufficiently upgrading Thunderbird. (More at https://support.mozilla.org/t5/Set-up-email/Thunderbird-and-Gmail/ta-p/14181)). -- You received this message because you are subscribed to the Google Groups "Racket Users" group. To unsubscribe from this group and stop receiving emails from it, send an email to racket-users+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
Re: [racket-users] IMAP with racket
Cool, thank you! I had no idea about parameterize. I will try that and continue my investigations. -- You received this message because you are subscribed to the Google Groups "Racket Users" group. To unsubscribe from this group and stop receiving emails from it, send an email to racket-users+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
Re: [racket-users] IMAP with racket
P.s. For that matter couldn't folder also be optional, defaulting to "INBOX"? -- You received this message because you are subscribed to the Google Groups "Racket Users" group. To unsubscribe from this group and stop receiving emails from it, send an email to racket-users+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
Re: [racket-users] IMAP with racket
hi, I'm finally finding time to dig into this a little and have a question about https://docs.racket-lang.org/net/imap.html#%28def._%28%28lib._net%2Fimap..rkt%29._imap-port-number%29%29 Does this make imap-port-number a kind of global variable? My naive view is it would be somewhat friendlier to make it an optional parameter to imap-connect along the lines of [ #:tls? tls? #:try-tls? try-tls?] but defaulting to 143. Does it become an attribute of an open imap-connection or does it remain a global, say if I hypothetically had two imap-connections going at once? I will experiment and maybe learn more, but thought I'd ask about this in the meantime. Cheers, Tim -- You received this message because you are subscribed to the Google Groups "Racket Users" group. To unsubscribe from this group and stop receiving emails from it, send an email to racket-users+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
Re: [racket-users] IMAP with racket
Thanks for both answers! I'll report back when I've made some progress! Cheers, Tim -- You received this message because you are subscribed to the Google Groups "Racket Users" group. To unsubscribe from this group and stop receiving emails from it, send an email to racket-users+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
[racket-users] IMAP with racket
Hi, I think I'd like to try using racket as a way to explore relatively simple ways of getting a grip on some mail accounts that have gotten out of hand. Specifically I'd like to be able to - compute some statistics, such as number of mails from various addresses - reorganize / clean-up, say by moving mails into folders according to rules or deleting mails from specific senders older than a given amount I have done similar things in the past using built-in functions in mail clients such as outlook or entourage. (If thunderbird supports such functions I could use that now, but I haven't found clues that it does; I even looked at AppleScript and began using it to explore, but quickly got pretty frustrated with the language and its documentation.) I like racket, though, and it would seem to be great to be able to try out functions interactively in the REPL. My impression on first glance though, was that the built-in IMAP support would require quite a bit of assembly and additions. I also found SirMail, which looks like more than what I need, though presumably I could make use of its foundation parts if I could figure out which and how. Might it be appropriate to build something between the IMAP basics and SirMail? Alternatively, is there a brief how-to for SirMail? I found the sources on github and they seemed to work immediately, but I have some questions about set-up. Perhaps I could even help write a brief "how to" with input from the authors? (Maybe there are more appropriate, "easier" ways of doing what I want to do that others think of immediately, in which case clues would be appreciated.) -- You received this message because you are subscribed to the Google Groups "Racket Users" group. To unsubscribe from this group and stop receiving emails from it, send an email to racket-users+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
[racket-users] reading UTF-16 from a file
hi, I was hoping yesterday to read UTF-16 characters from a file using, e.g., a small snippet such as the following: (for ([c (in-port read-char (open-input-file "myfile.txt"))] [counter naturals] #:break (>= counter 100)) (printf "(~a [~a]) " c (char->integer c))) For a UFT-16 file (that came from windows and perhaps for that reason has a byte order mark -- not sure) that be begins "11 Nov" I got: (� [65533]) (� [65533]) (1 [49]) ( [0]) (1 [49]) ( [0]) ( [32]) ( [0]) (N [78]) ( [0]) (o [111]) ( [0]) (v [118]) ( [0]) I suspect I need to do something with encodings, but I wasn't able to figure it out with a quick scan through documentation and searches in this group. Perhaps someone could give me a quick nudge in the right direction? Cheers, Tim p.s. maybe there's an easier way to get an arbitrary counter than what i did here? (define (integers-starting-from n) (stream-cons n (integers-starting-from (+ n 1 (define naturals (integers-starting-from 1)) This worked fine for me, so I didn't worry about it... -- You received this message because you are subscribed to the Google Groups "Racket Users" group. To unsubscribe from this group and stop receiving emails from it, send an email to racket-users+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
[racket-users] Re: regexp question
On Friday, October 30, 2015 at 10:35:19 PM UTC+1, Matthew Butterick wrote:
> [[:space:]] and similar matchers also require #px.
>
> As for the difference between #rx and #px:
>
> "The pregexp ... procedures produce a regexp value using a slightly different
> syntax of regular expressions that is more compatible with Perl."
>
> That must be the only thing in Racket influenced by Perl.
>
>
>
>
> On Friday, October 30, 2015 at 11:46:27 AM UTC-7, Tim Hanson wrote:
> > On Friday, October 30, 2015 at 7:21:58 PM UTC+1, Matthew Butterick wrote:
> > > To use \s as a matcher, you need #px not #rx:
> > >
> > > (define rx-empty-or-all-blank-string
> > > ;#rx"^[[:space:]]*$")
> > > #px"^\\s*$")
> > >
> > > See
> > > http://docs.racket-lang.org/reference/regexp.html?q=pregexp#%28elem._%28rxex._25%29%29
> > >
> > >
> > > On Friday, October 30, 2015 at 11:15:08 AM UTC-7, Tim Hanson wrote:
> > > > hi,
> > > >
> > > > I must be overlooking something basic, but can't figure out why the
> > > > second and third tests here fail. (Makes no difference whether I spell
> > > > {space-character} the [[:space:]] or the \\s way.)
> > > >
> > > > I'd be grateful for enlightenment. :)
> > > >
> > > > Cheers,
> > > >
> > > > Tim
> > > >
> > > > (define rx-empty-or-all-blank-string
> > > > ;#rx"^[[:space:]]*$")
> > > > #rx"^\\s*$")
> > > >
> > > > (check-equal? (regexp-match? rx-empty-or-all-blank-string "") #t)
> > > >
> > > > (check-equal? (regexp-match? rx-empty-or-all-blank-string " \t ") #t)
> > > >
> > > > (check-equal? (regexp-match? rx-empty-or-all-blank-string " \t\n") #t)
> >
> > ok, thx muchly. saw #px but didn't see the explanation / distinction.
> >
> > if it's easy to explain, why does the other one also fail?
> >
> > cheers,
> >
> > Tim
Ok, thanks, much. The examples were quite dense and I didn't read them
completely (I have quite a bit of regexp experience in other settings), but now
I see the helpful comments re #px on the right. All my tests went green the
moment I switched to #px (not just these), so I am a happy camper.
Cheers,
Tim
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[racket-users] Re: regexp question
On Friday, October 30, 2015 at 7:21:58 PM UTC+1, Matthew Butterick wrote:
> To use \s as a matcher, you need #px not #rx:
>
> (define rx-empty-or-all-blank-string
> ;#rx"^[[:space:]]*$")
> #px"^\\s*$")
>
> See
> http://docs.racket-lang.org/reference/regexp.html?q=pregexp#%28elem._%28rxex._25%29%29
>
>
> On Friday, October 30, 2015 at 11:15:08 AM UTC-7, Tim Hanson wrote:
> > hi,
> >
> > I must be overlooking something basic, but can't figure out why the second
> > and third tests here fail. (Makes no difference whether I spell
> > {space-character} the [[:space:]] or the \\s way.)
> >
> > I'd be grateful for enlightenment. :)
> >
> > Cheers,
> >
> > Tim
> >
> > (define rx-empty-or-all-blank-string
> > ;#rx"^[[:space:]]*$")
> > #rx"^\\s*$")
> >
> > (check-equal? (regexp-match? rx-empty-or-all-blank-string "") #t)
> >
> > (check-equal? (regexp-match? rx-empty-or-all-blank-string " \t ") #t)
> >
> > (check-equal? (regexp-match? rx-empty-or-all-blank-string " \t\n") #t)
ok, thx muchly. saw #px but didn't see the explanation / distinction.
if it's easy to explain, why does the other one also fail?
cheers,
Tim
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[racket-users] regexp question
hi,
I must be overlooking something basic, but can't figure out why the second and
third tests here fail. (Makes no difference whether I spell {space-character}
the [[:space:]] or the \\s way.)
I'd be grateful for enlightenment. :)
Cheers,
Tim
(define rx-empty-or-all-blank-string
;#rx"^[[:space:]]*$")
#rx"^\\s*$")
(check-equal? (regexp-match? rx-empty-or-all-blank-string "") #t)
(check-equal? (regexp-match? rx-empty-or-all-blank-string " \t ") #t)
(check-equal? (regexp-match? rx-empty-or-all-blank-string " \t\n") #t)
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