Ok, so I'm running some loops to process data stored in list objects. Ever mindful of the infamous fortune admonishment not to use eval(parse(mystring)), I came up with this:
Rgames> bar
$foo
$foo$fast
[1] 1 2 3 4 5
$foo$slow
[1] 6 7 8 9 10
$oof
$oof[[1]]
[1] 6 7 8 9 10
$oof[[2]]
[1] 1 2 3 4 5
Rgames> rab<-'bar'
Rgames> do.call('$',list(as.name(rab),'oof'))
[[1]]
[1] 6 7 8 9 10
[[2]]
[1] 1 2 3 4 5
Typically I'd be selecting a list (of which bar is one such) and then one element of the list (e.g. oof) which contains my data. The code above does the same thing as eval(parse(text=paste(rab,'$','oof',sep=''))) .
I'm doing all this specifically because I want to use the lists' names rather than [[x]] notation as a safety mechanism (because not all list objects have their contents in the same order).
Should I stick with the advice from DWin in R: eval(parse(...)) is often suboptimal ?
Using get and [[:
bar <- list(foo = list(fast = 1:5, slow = 6:10),
oof = list(6:10, 1:5))
rab <- 'bar'
get(rab)[['oof']]
# [[1]]
# [1] 6 7 8 9 10
#
# [[2]]
# [1] 1 2 3 4 5