[Rd] validity testing as part of '@<-'
fparlamis at mac.com
Thu Sep 21 23:29:38 CEST 2006
'methods' package feature request / discussion starter:
perhaps a call to 'validObject' should occur at part of any slot
replacement operation (and the operation not be carried out if it
would invalidate the object)? this may prevent the need for
prophylactic 'validObject' calls in other user-defined functions. in
the example below, the slot assignment occurs even though it
invalidates the object. the 'show' method then fails somewhat deep
in a subsequently-called coercion method.
test <- Matrix(1:4+0.1, nrow = 2, dimnames = list(letters[1:2],
test at Dimnames <- list(1:100)
direct slot access (without a validity check) seems an easily
accessible loophole to S4 object "guarantees".
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