[R] modify the imported version of a function

Benjamin Tyner btyner at gmail.com
Sat Dec 17 00:06:12 CET 2016


I saw on the assignInNamespace help page, that it changes "the copy in 
the namespace, but not any copies already exported from the namespace, 
in particular an object of that name in the package (if already 
attached) and any copies already imported into other namespaces."

So now I'm wondering, whether there is a way to modify such copies 
already imported into other namespaces? For a concrete example, consider 
the lint package (now archived on CRAN) which includes a function 
check_pattern, which calls stringr:::perl, which has been deprecated in 
newer versions:

    > stringr:::perl
    function (pattern)
        message("perl is deprecated. Please use regexp instead")
    <environment: namespace:stringr>

so, what if I wanted to directly replace stringr:::perl with 
stringr:::regex, in such a way that lint::check_pattern sees the 
replacement? Is there a way, preferably without having to attach stringr 
to the search path?

(I'm mostly just interested in learning about how namespace imports 
actually work; of course in this toy example one could use 
suppressMessages to hide that deprecation message).


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