R help - Sep 2001 - R package & namespace questions

Hi,

i'm unclear on ".Internal" functions in R.
Do ".Internal" functions mean:
1) functions (to be) used only inside a package (like private methods)
or
2) do they mean functions that call upon the R - C interface?


Related to this, how are namespaces handled in R?
It seems that i could write a function read.table(), place it in my own file,
source the file and there would be *no warning* that it interferes with the base
package's read.table() function? This seems quite unsafe to me coming from a
Java background where namespaces are very controlled.

I guess my question boils down to asking if the object manager in R maintains
function names as: functionname or as pkg::functionname

Finally, a function i wrote, placed in a file.R and sourc'ed:
misc.expand_table <- function(vec, n)
{
# something
}

seems to redefine the base function "table".


Thanks for any suggestions or comments.

ken



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On Mon, 17 Sep 2001 18:47:36 -0400, you wrote:
>Hi,
>
>i'm unclear on ".Internal" functions in R.
>Do ".Internal" functions mean:
>1) functions (to be) used only inside a package (like private methods)
>or
>2) do they mean functions that call upon the R - C interface?
They're functions that are written in C as part of the R source code.
>Related to this, how are namespaces handled in R?
They aren't, but I believe I heard they are being planned.  No idea
when they'll arrive.
 
>It seems that i could write a function read.table(), place it in my own
file, source the file and there would be *no warning* that it interferes with
the base package's read.table() function?  This seems quite unsafe to me
coming from a Java background where namespaces are very controlled.
Yes, it is dangerous.  Note though that if you did the same thing in a
package, you would get a warning about it.  Packages are a good idea.
>Finally, a function i wrote, placed in a file.R and sourc'ed:
>misc.expand_table <- function(vec, n)
>{
># something
>}
>
>seems to redefine the base function "table".
That's because the underscore is a synonym for the assignment operator
<-.  Your first line is equivalent to 

 misc.expand <- table <- function(vec,n)

Duncan Murdoch
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Send "info", "help", or "[un]subscribe"
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