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[R-pkg-devel] Should a package run without calling library?

2 messages · Richel Bilderbeek, Uwe Ligges

Original
Richel Bilderbeek
# 
Dear fellow R package maintainers,

I would enjoy your advice to clarify a CRAN policy issue.

The question is: should a package be able to work, when calling its exported functions using the scope operator? Or, in the example code below, should #1 work?



```
# 1. Scope operator: should this always work?
mypackage::myfunction()

# Possible error message:
# Error in myfunction() :
# object 'myhiddenfunction' of mode 'function' was not found


# 2. Calling library first
library(mypackage)
myfunction()
```

I feel the answer is 'yes, #1 should work', as I feel this is only indirectly a CRAN repository policy [1] , the IMHO relevant one which I quote: 'Packages should not modify the global environment (user?s workspace).'. This means that if I have a function that calls `mypackage::myfunction`, it will call `library`:


```
#' Function in another package, that depends on my package
do_something <- function() {
library(mypackage)
myfunction()
}
```

So, should a package be able to work, when calling its exported functions using the scope operator?

Thanks for your advice/pointers, Richel Bilderbeek


* [1] <https://mirror.las.iastate.edu/CRAN/web/packages/policies.html>
Uwe Ligges
#
On 01.09.2020 09:43, Richel Bilderbeek wrote:
Yes.
Yes.
No, it can import from the namespace, i.e. it loads the package, but 
does not modify the search path (i.e. does not attach the package).

Also note the workspace (=.GlobalEnv) is not the search path.

Best,
Uwe Ligges