How to check something that "is not yet implemented" in Swift 3 Linux

How to grep "XXXX is not yet implemented" in Swift 3 Linux
cd $(HOME) git clone --depth=1 https://github.com/apple/swift-corelibs-foundation
cd $(HOME)/swift-corelibs-foundation/Foundation
grep -r "NSUnimplemented() }"



How to grep func or init in Swift 3 Linux
cd $(HOME)/swift-corelibs-foundation/Foundation
grep -r "open func \|public init"