Displaying 1 result from an estimated 1 matches for "externalcallerenv".
2012 Aug 29
0
"Ambiguous" variation of default environment in `getClasses()` (standard function vs. formal S4 method)
...his was/is quite an interesting and
unexpected behavior which I thought might be worth sharing:
The default value of argument |where|in function |getClasses()|seems to
vary depending on whether |getClasses()|is called inside a *standard R
function*or a *formal S4 method*. It is controlled by
|.externalCallerEnv()|, which seems to be "vulnerable" to /lazy
evaluation/and/or an "altered" /lexical scoping/structure (possible
introduced by the definition of a formals S4 method?) and thus causes
the variation**.
I found it quite hard to understand what's exactly going on as you need...