migrating dfs to swift3

Depth-First Search/DepthFirstSearch.playground/Pages/Simple Example.xcplaygroundpage/Contents.swift

@@ -1,4 +1,4 @@
-func depthFirstSearch(graph: Graph, source: Node) -> [String] {
+func depthFirstSearch(_ graph: Graph, source: Node) -> [String] {
   var nodesExplored = [source.label]
   source.visited = true
 

Depth-First Search/DepthFirstSearch.playground/Sources/Edge.swift

@@ -1,11 +1,11 @@
 public class Edge: Equatable {
   public var neighbor: Node
 
-  public init(neighbor: Node) {
+  public init(_ neighbor: Node) {
     self.neighbor = neighbor
   }
 }
 
-public func == (lhs: Edge, rhs: Edge) -> Bool {
+public func == (_ lhs: Edge, rhs: Edge) -> Bool {
   return lhs.neighbor == rhs.neighbor
 }

Depth-First Search/DepthFirstSearch.playground/Sources/Graph.swift

@@ -5,14 +5,14 @@ public class Graph: CustomStringConvertible, Equatable {
     self.nodes = []
   }
 
-  public func addNode(label: String) -> Node {
-    let node = Node(label: label)
+  public func addNode(_ label: String) -> Node {
+    let node = Node(label)
     nodes.append(node)
     return node
   }
 
-  public func addEdge(source: Node, neighbor: Node) {
-    let edge = Edge(neighbor: neighbor)
+  public func addEdge(_ source: Node, neighbor: Node) {
+    let edge = Edge(neighbor)
     source.neighbors.append(edge)
   }
 
@@ -27,7 +27,7 @@ public class Graph: CustomStringConvertible, Equatable {
     return description
   }
 
-  public func findNodeWithLabel(label: String) -> Node {
+  public func findNodeWithLabel(_ label: String) -> Node {
     return nodes.filter { $0.label == label }.first!
   }
 
@@ -50,6 +50,6 @@ public class Graph: CustomStringConvertible, Equatable {
   }
 }
 
-public func == (lhs: Graph, rhs: Graph) -> Bool {
+public func == (_ lhs: Graph, rhs: Graph) -> Bool {
   return lhs.nodes == rhs.nodes
 }

Depth-First Search/DepthFirstSearch.playground/Sources/Node.swift

@@ -5,7 +5,7 @@ public class Node: CustomStringConvertible, Equatable {
   public var distance: Int?
   public var visited: Bool
 
-  public init(label: String) {
+  public init(_ label: String) {
     self.label = label
     neighbors = []
     visited = false
@@ -22,11 +22,11 @@ public class Node: CustomStringConvertible, Equatable {
     return distance != nil
   }
 
-  public func remove(edge: Edge) {
-    neighbors.removeAtIndex(neighbors.indexOf { $0 === edge }!)
+  public func remove(_ edge: Edge) {
+    neighbors.remove(at: neighbors.index { $0 === edge }!)
   }
 }
 
-public func == (lhs: Node, rhs: Node) -> Bool {
+public func == (_ lhs: Node, rhs: Node) -> Bool {
   return lhs.label == rhs.label && lhs.neighbors == rhs.neighbors
 }

Depth-First Search/DepthFirstSearch.swift

@@ -1,4 +1,4 @@
-func depthFirstSearch(graph: Graph, source: Node) -> [String] {
+func depthFirstSearch(_ graph: Graph, source: Node) -> [String] {
   var nodesExplored = [source.label]
   source.visited = true
 

Depth-First Search/README.markdown

@@ -27,7 +27,7 @@ The parent of a node is the one that "discovered" that node. The root of the tre
 Simple recursive implementation of depth-first search:
 
 ```swift
-func depthFirstSearch(graph: Graph, source: Node) -> [String] {
+func depthFirstSearch(_ graph: Graph, source: Node) -> [String] {
   var nodesExplored = [source.label]
   source.visited = true