Duncan,
  That's helpful.  Two follow-up questions:
1. Where would I have found this information?  I had looked at eval and 
model.frame.
2. What stops the following code from falling down the same rabbit hole? Shouldn't it find base::cos first?

   library(survival)
   cos <- lung
   coxph(Surv(time, status) ~ age, data=cos)

Terry T.


On 11/06/2015 07:51 AM, Duncan Murdoch wrote:
On 06/11/2015 7:36 AM, Therneau, Terry M., Ph.D. wrote:
I am currently puzzled by a seach path behavior.  I have a library of a dozen 
routines
getlabs(), getssn(), getecg(), ... that interface to local repositories and 
pull back
patient information.  All have a the first 6 arguments in common, and 
immediately call a
second routine to do initial processing of these 6.  The functions "joe" and 
"fred" below
capture the relevant portion of them.
    My puzzle is this: the last test in the "test" file works fine if these 
routines are
sourced and executed at the command line, it fails if the routines are bundled 
up and
loaded as a library. That test is motivated by a user who called his data set 
"t", and
ended up with a match to base:::t instead of his data, resulting in a strange 
error
message out of model.frame  --- you can always count on the users!  (There are 
a few
hundred.)
     I'm attempting to be careful with envr and enclos arguments -- how does 
base end up
earlier in the search path?   Perhaps this is clearly stated in the docs and 
just not
clear to me?  A working solution to the dilemma is of course more than welcome.

I haven't followed through all the details in fred(), but I can answer the last 
question.
In package code, the search order is:

- the package environment
- the imports to the package (with base being an implicit import)
- the global environment and the rest of the search list.

In code sourced to the global environment, only the third of these is searched. 
 Since
base is in the second one, it is found first in the package version.

Duncan Murdoch

______________________________________________
R-devel@r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-devel

Reply via email to