Dear help, dear John Chambers,
I'm trying to learn OOP-possibilities in R and I was going through the 
documentation 'ReferenceClasses {methods}'. (great work, by the way...)
Reading associated Examples, something bothers me : it seems to me that there 
are errors in 'edit' and 'undo' methods. I think that :
- 'undo' should update 'edits' field with :
length(edits) <<- length(edits) - 1 #(and not - 2)
- and for coherence, 'edit' should store modifications in an 'append'-style :
edits <<- c(edits,list(backup)) #as opposed to c(list(backup),edits)

I hope I'm not wrong.

As a complementary question, suppose one kept 'c(edits,list(backup))', does 
anyone know how todiscard first element(s) of a list? For a vector :
vedits<<-vedits[-1]
But lists can't be selected that way ( edits<<- edits [[-1]] #wrong )

Bye.

Marc


      
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