cocoa - Format string for NSPredicate with @avg collection operator -


is there way construct nspredicate following array can filtered average score larger than, say, 5?

nsarray *objs = @[ @{@"scores":@[@3, @5, @2]}, @{@"scores":@[@5, @2, @8, @9]}, @{@"scores":@[@7, @1, @4]} ];

i have tried various combinations, of 1 seemed promising (considering key path @avg.self works obtain average value of numbers in array through normal kvc):

nspredicate *pred = [nspredicate predicatewithformat:@"scores.@avg.self > 5"]; nsarray     *filterd = [objs filteredarrayusingpredicate:pred];

the runtime error following:

nsunknownkeyexception', reason: '[<__nsarrayi 0x10011b7c0> valueforundefinedkey:]: class not key value coding-compliant key avg.

this predicate string works: scores.@count > 3, @ least collection operator can used in predicate.

if change scores.@avg.self > 5 scores.@avg.doublevalue > 5 work fine.


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