In the long run this is probably better than what I wanted. Thank you
On Friday, February 2, 2018 at 12:23:48 PM UTC-6, johnbclements wrote:
>
> Not sure if this gets you as far as you want, but you could use a macro to
> associate names with paren-wrapped items:
>
> #lang racket
>
> (define-syntax re-match
> (syntax-rules ()
> [(_ str re name ...)
> (match str
> [(regexp re (list _ name ...))
> (list (list (quote name) name) ...)])]))
>
> (define msg "2018-02-02T11:26:34 someuser some-computername01
> 233.194.20.110 something broke")
>
> (re-match msg
> #px"^([-\\dT:]+)\\s(\\w+)\\s([-\\w\\d]+)\\s([\\d\\.]+)\\s(.+)$"
> date username hostname ip message)
>
> … produces:
>
> '((date "2018-02-02T11:26:34")
> (username "someuser")
> (hostname "some-computername01")
> (ip "233.194.20.110")
> (message "something broke”))
>
>
> This macro gets the names in much closer to the corresponding patterns
> than matching by index, but it doesn’t actually embed the names into the
> regexp.
>
> John Clements
>
>
> > On Feb 2, 2018, at 10:01 AM, noch...@gmail.com <javascript:> wrote:
> >
> > Sorry if I've missed this in the documentation, but I don't see it, and
> it is starting to bother me.
> >
> > In Powershell. Python, and Splunk I'm able to perform automatic field
> extraction on strings and access the values of fields by name. Is there a
> way to do this in Racket? Of course, pairing matches with field names by
> index is an option, but not as convenient in some situations.
> >
> > Take string "2018-02-02T11:26:34 someuser some-computername01
> 233.194.20.110 something broke" as a trivial example.
> >
> > Powershell:
> > "2018-02-02T11:26:34 someuser some-computername01 233.194.20.110
> something broke" -match
> "^(?<Date>[\d\-T:]+)\s(?<Username>\w+)\s(?<Hostname>[\w\-\d]+)\s(?<IP>[\d\.]+)\s(?<Message>.+)$"
>
> | Out-Null
> >
> > $matches.date
> > $matches.username
> > $matches.hostname
> > $matches.IP
> > $matches.message
> >
> > Python:
> > m =
> re.match("^(?P<Date>[\d\-T:]+)\s(?P<Username>\w+)\s(?P<Hostname>[\w\-\d]+)\s(?P<IP>[\d\.]+)\s(?P<Message>.+)$",
>
> "2018-02-02T11:26:34 someuser some-computername01 233.194.20.110 something
> broke")
> >
> > m['Date']
> > m['Username']
> > m['Hostname']
> > m['IP']
> > m['Message']
> >
> > Both output:
> >
> > 2018-02-02T11:26:34
> > someuser
> > some-computername01
> > 233.194.20.110
> > something broke
> >
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>
>
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