>dealing with immutable data in OO languages is tedious and error prone I don't think this is a problem ingrained in OO. You could very easily conceive of an "

>dealing with immutable data in OO languages is tedious and error prone I don't think this is a problem ingrained in OO. You could very easily conceive of an "OO" language that has separate constructs for objects (mutable) and data (immutable) and there would be no problem at all. Immutable data just happens to be common in functional languages but there's no reason you couldn't introduce it to an "OO" language.