CODEWITHSUNDEEP
iosarraysswiftgenerics
János
János

Reputation: 35050

Complements / intersection of two generic array filled with NSIndexPath

ipsToReload.filter { !contains(self.ipsToInsert, {$0.row == $1.row}) }

I want to get this expression work. I need complements of the two generic array: ipsToReload \ ipsToInsert. Any idea what I am doing wrong?

This is the definition:

var ipsToInsert = [NSIndexPath]()
var ipsToDelete = [NSIndexPath]()

enter image description here

Upvotes: 1

Views: 70

Answers (1)

Airspeed Velocity
Airspeed Velocity

Reputation: 40965

The trouble is that you have two nested closure expressions (the one to filter, and the one to contains). But within a closure expression, $0 and $1 refer to arguments local to that closure expression – so in this case, you are writing an expression for contains that takes two arguments ($0 and $1), and then the closure argument to filter looks as if it takes no arguments (hence Swift is complaining that you can't pass a ()->_ argument into filter).

Try naming the arguments, like so:

ipsToReload.filter { reload in 
    !contains(ipsToInsert) { insert in 
        reload.row == insert.row 
    } 
}

Upvotes: 2

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