R help - Dec 2008 - recursive List extraction question

Dear all,
I've got a list 
L <- list(L1 = list
          (foo = "bar"
           , SL = NULL
           )
          , L2 = list
          (
           foo = "bar"
           , SL = list
           (SSL1 = list
            (DF = data.frame(val = 21, foo = "bar")
             , DFOO = list(foo = "foo", bar = "bar")
             )
            , SSL2 = list
            (DF = data.frame(val = 22, foo = "bar")
             , DFOO = list(foo = "foo", bar = "bar")
             )
            )

           )
          , L3 = list
          (
           foo = "bar"
           , SL = list
           (SSL1 = list
            (DF = data.frame(val=31, foo="bar")
             , DFOO = list(foo="foo", bar="bar")
             )
            )
           )
          )
from which I'ld like to extract the values 21,22 and 31.

lapply(
       lapply(
              lapply(
                     lapply(L, "[[","SL")
                     ,"[[",1)
              ,"[[","DF")
       ,"[[","val") 

gives me 21 and 31. Because of lapply(...,"[[",1), it searches 
through
the first element of each SL, which are the SSL1. It misses SSL2. Is
there a way to replace the ,"[[",1), with a regex or the like to get
the
job done? Does anybody now any other solution? 
Thanks and regards,
Dominik


----------------------------------------------
Andreas Dominik Cullmann
Forstliche Versuchs- und Forschungsanstalt 
Wonnhalde 4 
79100 Freiburg 
Tel. +49 761 4018 204 
Email: dominik.cullmann at forst.bwl.de
<mailto:dominik.cullmann at forst.bwl.de> 
Homepage: www.fva-bw.de <http://www.fva-bw.de>

Try this:

rapply(L, c)[grep("\\.val$", names(rapply(L, c)))]

On Fri, Dec 12, 2008 at 7:55 AM, <Dominik.Cullmann@forst.bwl.de> wrote:
> Dear all,
> I've got a list
> L <- list(L1 = list
>          (foo = "bar"
>           , SL = NULL
>           )
>          , L2 = list
>          (
>           foo = "bar"
>           , SL = list
>           (SSL1 = list
>            (DF = data.frame(val = 21, foo = "bar")
>             , DFOO = list(foo = "foo", bar = "bar")
>             )
>            , SSL2 = list
>            (DF = data.frame(val = 22, foo = "bar")
>             , DFOO = list(foo = "foo", bar = "bar")
>             )
>            )
>
>           )
>          , L3 = list
>          (
>           foo = "bar"
>           , SL = list
>           (SSL1 = list
>            (DF = data.frame(val=31, foo="bar")
>             , DFOO = list(foo="foo", bar="bar")
>             )
>            )
>           )
>          )
> from which I'ld like to extract the values 21,22 and 31.
>
> lapply(
>       lapply(
>              lapply(
>                     lapply(L, "[[","SL")
>                     ,"[[",1)
>              ,"[[","DF")
>       ,"[[","val")
>
> gives me 21 and 31. Because of lapply(...,"[[",1), it searches 
through
> the first element of each SL, which are the SSL1. It misses SSL2. Is
> there a way to replace the ,"[[",1), with a regex or the like to
get the
> job done? Does anybody now any other solution?
> Thanks and regards,
> Dominik
>
>
> ----------------------------------------------
> Andreas Dominik Cullmann
> Forstliche Versuchs- und Forschungsanstalt
> Wonnhalde 4
> 79100 Freiburg
> Tel. +49 761 4018 204
> Email: dominik.cullmann@forst.bwl.de
> <mailto:dominik.cullmann@forst.bwl.de>
> Homepage: www.fva-bw.de <http://www.fva-bw.de>
>
> ______________________________________________
> R-help@r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide
> http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
>


-- 
Henrique Dallazuanna
Curitiba-Paraná-Brasil
25° 25' 40" S 49° 16' 22" O

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