Re: [Rd] Restrict access to variables in parent environment
This isn't like a local variable though, since any function above the
baseenv() in the search path will also not be found.
f
function(a) { rnorm(b) }
environment: base
f()
Error in f() : could not find function rnorm
Jeff
On Fri, May 14, 2010 at 9:20 AM, Hadley Wickham had...@rice.edu wrote:
Hello All,
By default, a reference of a variable in a function cause R to look
for the variable in the parent environment if it is not available in
the current environment (without generating any errors or warnings).
I'm wondering if there is a way to revert this behaviors, such that it
will not look for the parent environment and will generate an error if
the variable is not available in the current environment. Is this
tuning has to be done at the C level?
Try this:
b - 1
f - function(a) {
b
}
environment(f) - baseenv()
f()
Hadley
--
Assistant Professor / Dobelman Family Junior Chair
Department of Statistics / Rice University
http://had.co.nz/
__
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Jeffrey Ryan
jeffrey.r...@insightalgo.com
ia: insight algorithmics
www.insightalgo.com
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Re: [Rd] Restrict access to variables in parent environment
You can get around that by using this instead:
environment(f) - as.environment(2)
provided it is done after you have loaded all your packages.
On Fri, May 14, 2010 at 10:29 AM, Jeff Ryan jeff.a.r...@gmail.com wrote:
This isn't like a local variable though, since any function above the
baseenv() in the search path will also not be found.
f
function(a) { rnorm(b) }
environment: base
f()
Error in f() : could not find function rnorm
Jeff
On Fri, May 14, 2010 at 9:20 AM, Hadley Wickham had...@rice.edu wrote:
Hello All,
By default, a reference of a variable in a function cause R to look
for the variable in the parent environment if it is not available in
the current environment (without generating any errors or warnings).
I'm wondering if there is a way to revert this behaviors, such that it
will not look for the parent environment and will generate an error if
the variable is not available in the current environment. Is this
tuning has to be done at the C level?
Try this:
b - 1
f - function(a) {
b
}
environment(f) - baseenv()
f()
Hadley
--
Assistant Professor / Dobelman Family Junior Chair
Department of Statistics / Rice University
http://had.co.nz/
__
R-devel@r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-devel
--
Jeffrey Ryan
jeffrey.r...@insightalgo.com
ia: insight algorithmics
www.insightalgo.com
[[alternative HTML version deleted]]
__
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Re: [Rd] Restrict access to variables in parent environment
On Fri, May 14, 2010 at 10:10 AM, Gabor Grothendieck ggrothendi...@gmail.com wrote: You can get around that by using this instead: environment(f) - as.environment(2) provided it is done after you have loaded all your packages. Another approach is to inspect function by function: library(codetools) findGlobals(f, F)$variables Hadley -- Assistant Professor / Dobelman Family Junior Chair Department of Statistics / Rice University http://had.co.nz/ __ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel
Re: [Rd] Restrict access to variables in parent environment
On May 14, 2010, at 10:29 AM, Jeff Ryan wrote:
This isn't like a local variable though, since any function above the
baseenv() in the search path will also not be found.
Yes, but that is a consequence of the request and hence intended. You can
always either specify the full path to the function or assign locally any
functions you'll need:
f = function(a) stats::rnorm(b)
environment(f) - baseenv()
f()
Error in stats::rnorm(b) : object 'b' not found
f = function(a) { rnorm=stats::rnorm; rnorm(b) }
environment(f) - baseenv()
f()
Error in rnorm(b) : object 'b' not found
Alternatively you can use any environment up the search path hoping that those
won't define further variables.
But back to the original question -- if taken literally, it's quite useless
since it corresponds to using emptyenv() instead of baseenv() which means that
you can't do anything:
local(1+1,emptyenv())
Error in eval(expr, envir, enclos) : could not find function +
So likely the only useful(?) distinction would be to allow function lookup the
regular way but change only the variable lookup to not look beyond the current
environment. That is stretching it, though...
Cheers,
Simon
f
function(a) { rnorm(b) }
environment: base
f()
Error in f() : could not find function rnorm
Jeff
On Fri, May 14, 2010 at 9:20 AM, Hadley Wickham had...@rice.edu wrote:
Hello All,
By default, a reference of a variable in a function cause R to look
for the variable in the parent environment if it is not available in
the current environment (without generating any errors or warnings).
I'm wondering if there is a way to revert this behaviors, such that it
will not look for the parent environment and will generate an error if
the variable is not available in the current environment. Is this
tuning has to be done at the C level?
Try this:
b - 1
f - function(a) {
b
}
environment(f) - baseenv()
f()
Hadley
--
Assistant Professor / Dobelman Family Junior Chair
Department of Statistics / Rice University
http://had.co.nz/
__
R-devel@r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-devel
--
Jeffrey Ryan
jeffrey.r...@insightalgo.com
ia: insight algorithmics
www.insightalgo.com
[[alternative HTML version deleted]]
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Re: [Rd] Restrict access to variables in parent environment
On Fri, May 14, 2010 at 10:13 AM, Simon Urbanek
simon.urba...@r-project.org wrote:
On May 14, 2010, at 10:29 AM, Jeff Ryan wrote:
This isn't like a local variable though, since any function above the
baseenv() in the search path will also not be found.
Yes, but that is a consequence of the request and hence intended. You can
always either specify the full path to the function or assign locally any
functions you'll need:
f = function(a) stats::rnorm(b)
environment(f) - baseenv()
f()
Error in stats::rnorm(b) : object 'b' not found
f = function(a) { rnorm=stats::rnorm; rnorm(b) }
environment(f) - baseenv()
f()
Error in rnorm(b) : object 'b' not found
Alternatively you can use any environment up the search path hoping that
those won't define further variables.
But back to the original question -- if taken literally, it's quite useless
since it corresponds to using emptyenv() instead of baseenv() which means
that you can't do anything:
local(1+1,emptyenv())
Error in eval(expr, envir, enclos) : could not find function +
So likely the only useful(?) distinction would be to allow function lookup
the regular way but change only the variable lookup to not look beyond the
current environment. That is stretching it, though...
I didn't think of the corner cases. I'm OK with stats::rnorm or
stats:::rnorm. But '{' is not recognized. How to make it be
recognized?
b=1
f=function() {
stats::rnorm(b)
}
f()
#environment(f)=base()
environment(f)=emptyenv()
f()
Cheers,
Simon
f
function(a) { rnorm(b) }
environment: base
f()
Error in f() : could not find function rnorm
Jeff
On Fri, May 14, 2010 at 9:20 AM, Hadley Wickham had...@rice.edu wrote:
Hello All,
By default, a reference of a variable in a function cause R to look
for the variable in the parent environment if it is not available in
the current environment (without generating any errors or warnings).
I'm wondering if there is a way to revert this behaviors, such that it
will not look for the parent environment and will generate an error if
the variable is not available in the current environment. Is this
tuning has to be done at the C level?
Try this:
b - 1
f - function(a) {
b
}
environment(f) - baseenv()
f()
Hadley
--
Assistant Professor / Dobelman Family Junior Chair
Department of Statistics / Rice University
http://had.co.nz/
__
R-devel@r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-devel
--
Jeffrey Ryan
jeffrey.r...@insightalgo.com
ia: insight algorithmics
www.insightalgo.com
[[alternative HTML version deleted]]
__
R-devel@r-project.org mailing list
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__
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Tom
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Re: [Rd] Restrict access to variables in parent environment
On May 14, 2010, at 11:33 AM, thmsfuller...@gmail.com wrote:
On Fri, May 14, 2010 at 10:13 AM, Simon Urbanek
simon.urba...@r-project.org wrote:
On May 14, 2010, at 10:29 AM, Jeff Ryan wrote:
This isn't like a local variable though, since any function above the
baseenv() in the search path will also not be found.
Yes, but that is a consequence of the request and hence intended. You can
always either specify the full path to the function or assign locally any
functions you'll need:
f = function(a) stats::rnorm(b)
environment(f) - baseenv()
f()
Error in stats::rnorm(b) : object 'b' not found
f = function(a) { rnorm=stats::rnorm; rnorm(b) }
environment(f) - baseenv()
f()
Error in rnorm(b) : object 'b' not found
Alternatively you can use any environment up the search path hoping that
those won't define further variables.
But back to the original question -- if taken literally, it's quite useless
since it corresponds to using emptyenv() instead of baseenv() which means
that you can't do anything:
local(1+1,emptyenv())
Error in eval(expr, envir, enclos) : could not find function +
So likely the only useful(?) distinction would be to allow function lookup
the regular way but change only the variable lookup to not look beyond the
current environment. That is stretching it, though...
I didn't think of the corner cases. I'm OK with stats::rnorm or
stats:::rnorm. But '{' is not recognized. How to make it be
recognized?
You either include base or (if you don't want to) you have to create functions
for everything you'll need including `{` so for example:
f=function(a) base::rnorm(b)
environment(f)=mini.env
mini.env=new.env(parent=emptyenv())
import=c({,::,+,rnorm) # add all functions you want to use
for (fn in import) mini.env[[fn]] = get(fn)
f=function(a) rnorm(a+b)
environment(f)=mini.env
f(1)
Error in rnorm(a + b) : object 'b' not found
Cheers,
Simon
b=1
f=function() {
stats::rnorm(b)
}
f()
#environment(f)=base()
environment(f)=emptyenv()
f()
Cheers,
Simon
f
function(a) { rnorm(b) }
environment: base
f()
Error in f() : could not find function rnorm
Jeff
On Fri, May 14, 2010 at 9:20 AM, Hadley Wickham had...@rice.edu wrote:
Hello All,
By default, a reference of a variable in a function cause R to look
for the variable in the parent environment if it is not available in
the current environment (without generating any errors or warnings).
I'm wondering if there is a way to revert this behaviors, such that it
will not look for the parent environment and will generate an error if
the variable is not available in the current environment. Is this
tuning has to be done at the C level?
Try this:
b - 1
f - function(a) {
b
}
environment(f) - baseenv()
f()
Hadley
--
Assistant Professor / Dobelman Family Junior Chair
Department of Statistics / Rice University
http://had.co.nz/
__
R-devel@r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-devel
--
Jeffrey Ryan
jeffrey.r...@insightalgo.com
ia: insight algorithmics
www.insightalgo.com
[[alternative HTML version deleted]]
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Tom
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Re: [Rd] Restrict access to variables in parent environment
On 14/05/2010 10:14 AM, thmsfuller...@gmail.com wrote: Hello All, By default, a reference of a variable in a function cause R to look for the variable in the parent environment if it is not available in the current environment (without generating any errors or warnings). I'm wondering if there is a way to revert this behaviors, such that it will not look for the parent environment and will generate an error if the variable is not available in the current environment. Is this tuning has to be done at the C level? You could do that by setting the environment of the function to emptyenv(), but it will not be pretty. Remember that everything in R is an object, so you won't have access to the base level objects like +, or mean, or any other function. Duncan Murdoch __ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel
