Ordering of keys in encoded map. about swiftcbor HOT 4 CLOSED

Hm, you actually can easily encode the map in-order manually.

Instead of building an outer CBOR enum with dictionaryLiteral, just directly return the bytes for the map.

Encoding a map is simple, you just encode the count, OR the first byte with 0b101_00000, and encode the key-value pairs.

Something like

    public func encode() -> [UInt8] {
        var res: [UInt8] = Int(3).encode() // well, your actual count
        res[0] = res[0] | 0b101_00000
        res.append(contentsOf: 0.encode())
        res.append(contentsOf: 1001.encode())
        res.append(contentsOf: 1.encode())
        res.append(contentsOf: self.some_int32.encode())
        res.append(contentsOf: 2.encode())
        res.append(contentsOf: self.hasSome_int8() ? CBOR(integerLiteral: self.some_int8!) : CBOR(nilLiteral: ())) // CBOR enum itself is encodable
        return res
    }

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would it be possible to get the keys (integerLiteral) ordered in ascending order?

Not currently, our map representation is a Swift map, which doesn't preserve order :(

case map([CBOR : CBOR])

It would make sense to use a list of key-value pairs instead, but that's a breaking change (not that there's been a 1.0 release haha) and I won't be the one making that change (I don't have a Swift dev environment currently), sorry.

How do I get an Int value from a CBOR.unsignedInt ?

You get a UInt64 (or just UInt before recent changes) by pattern matching.

if case let CBOR.unsignedInt(int_val) = cbor_val {
    do_things_with(int_val);
}

I guess I should put a link to a pattern matching tutorial in the readme, since this is a frequently asked question...

from swiftcbor.

Thanks alot for the guide on the ordering of the map! I've managed to implement it.

I'm still relatively new to Swift, so I'm reading up on Swift pattern matching to get the UInt64 value.

Again, thanks alot for the quick replies :)

from swiftcbor.

Thanks alot for your help! I managed to get pattern matching to work for extracting the values from a CBOR object.

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