replaceMissingWithTRUE: Replace missing elements with TRUE
Description
When subsetting, missingness stands in for selecting all of the elements of that
dimension. This gets tricky when you are selecting n dimensions and so need to
capture the dimensions with .... This function checks if an element of a list
is missing and replaces that element with TRUE in order to handle this case.
Usage
replaceMissingWithTRUE(l)