>> Is it possible to "recursively" parse srcrefs to match the recursive
>> structure of the underlying code? I'm interested in this because it's
>
> I don't understand what you mean by that. It is certainly possible to walk
> through nested srcrefs, to zoom in on a particular location; that's what
> findLineNum() does.
Does the example below not help? Given the whole function, I want to
be able to walk down the call tree, finding the matching src refs as I
go. i.e. given f, how do I get f_inside?
f <- function(x = T) {
# This is a comment
if (x) return(4)
if (emergency_status()) return(T)
}
f_inside <- parse(text = "
# This is a comment
if (x) return(4)
if (emergency_status()) return(T)
")
findLineNum doesn't quite do what I want - it works on the text of the
srcref, not on the parse tree.
Here's another go at explaining what I want:
h <- quote(
1 # one
+ # plus
2 # two
)
h[[1]] extracts +. What can I do to extract "+ # plus" (on an object
created in the appropriate manner to keep the srcref)? Is that even
possible?
My eventual goal is something like
f <- function(x) {
# This is my function
T
}
g <- fix_logical_abbreviations(f)
which would be equivalent to
g <- function(x) {
# This is my function
TRUE
}
> That last display looks like a bug indeed. I'll take a look.
The key seems to be a leading newline:
parse(text = "\nx")
parse(text = "x")
Hadley
--
Assistant Professor / Dobelman Family Junior Chair
Department of Statistics / Rice University
http://had.co.nz/
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