Refactored Hash List implementation to generic model..

Source/Factories/Graph.swift

@@ -59,19 +59,19 @@ public class SwiftGraph {
 
 
         //check condition for an undirected graph
-        if (isDirected == false) {
+        if isDirected == false {
 
 
-            //create a new reversed edge
-            let reverseEdge = Edge()
+           //create a new reversed edge
+           let reverseEdge = Edge()
 
 
-            //establish the reversed properties
-            reverseEdge.neighbor = source
-            reverseEdge.weight = weight
-            neighbor.neighbors.append(reverseEdge)
+           //establish the reversed properties
+           reverseEdge.neighbor = source
+           reverseEdge.weight = weight
+           neighbor.neighbors.append(reverseEdge)
 
-            print("The neighbor of vertex: \(neighbor.key as String!) is \(source.key as String!)..")
+           print("The neighbor of vertex: \(neighbor.key as String!) is \(source.key as String!)..")
 
         }
 

Source/Factories/HashList.swift

@@ -23,22 +23,31 @@ class HashList<T> {
     }
 
 
+
     //add element to list
-    func append(_ element: T, key: String) -> HashResults {
+    func append(_ element: T) -> HashResults {
 
 
         let results: HashResults
+        var hashIndex = 0
 
 
-        //determine hash
-        let hashIndex = self.createHash(key)
+
+        //test list types
+        if let elementKey = model(with: element) {
+            hashIndex = self.createHash(elementKey)
+        }
+        else {
+            return HashResults.NotSupported
+        }
 
 
         //placeholder elements
-        let childToUse = HashElement<T>(withKey: key)
+        let childToUse = HashElement<T>()
         var head: HashElement<T>?
 
 
+
         childToUse.element = element
 
 
@@ -93,24 +102,75 @@ class HashList<T> {
         //check chained list for key
         while current != nil {
 
-            if current?.key == key {
-                print("element found..")
-                return (current, HashResults.Success)
+
+            //test model - compare element keys
+            if let elementKey = model(with: (current?.element)!) {
+
+                if elementKey == key {
+                    print("element found..")
+                    return (current, HashResults.Success)
+                }                
             }
 
             print("searching through chained list..")
             current = current?.next
+
         }
 
-
         return (nil, HashResults.Fail)
 
     }
 
+
+
+
+    //MARK: Helper Functions
 
 
-    //MARK: Helper Function
 
+    //determine supported list types
+    func model(with element: T) -> String? {
+
+
+        /*
+         note: since various structures will manage key data differently, 
+         this model can be extended to support different types.
+        */
+
+        switch element {
+
+
+        //string type
+        case is String:
+            return String(element)
+
+
+
+        //int type
+        case is Int:
+            let stringElement = String(element)
+            return stringElement
+
+
+
+        //vertex type
+        case is Vertex:
+            if let eVertex = element as? Vertex {
+                return eVertex.key
+            }
+            else {
+                return nil
+            }
+
+
+        default:
+            return nil
+        }
+
+
+    }
+
+
 
 
     //hash based on string
@@ -131,7 +191,7 @@ class HashList<T> {
 
         remainder = divisor % buckets.count
 
-        return remainder - 1
+        return remainder
     }
 
 

Source/Factories/PathHeap.swift

@@ -28,20 +28,21 @@ public class PathHeap {
     //obtain the minimum path
     func peek() -> Path! {
 
-        if (heap.count > 0) {
-            return heap[0] //the shortest path
+        if heap.count > 0 {
+           return heap[0] //the shortest path
         }
         else {
             return nil
         }
+
     }
 
 
 
     //remove the minimum path
     func deQueue() {
 
-        if (heap.count > 0) {
+        if heap.count > 0 {
             heap.remove(at: 0)
         }
 

Source/Structures/HashElement.swift

@@ -13,13 +13,6 @@ import Foundation
 
 class HashElement<T> {
 
-    var key: String
     var element: T?
     var next: HashElement<T>?
-
-
-    init(withKey key: String) {
-        self.key = key
-    }
-
 }

Source/Structures/enums.swift

@@ -29,6 +29,7 @@ enum HashResults {
     case Success
     case Collision
     case NotFound
+    case NotSupported
     case Fail
 }
 

SwiftStructures.xcodeproj/xcuserdata/waynebishop.xcuserdatad/xcdebugger/Breakpoints_v2.xcbkptlist

@@ -145,5 +145,37 @@
             landmarkType = "7">
          </BreakpointContent>
       </BreakpointProxy>
+      <BreakpointProxy
+         BreakpointExtensionID = "Xcode.Breakpoint.FileBreakpoint">
+         <BreakpointContent
+            shouldBeEnabled = "No"
+            ignoreCount = "0"
+            continueAfterRunningActions = "No"
+            filePath = "SwiftTests/ListTest.swift"
+            timestampString = "490838503.068996"
+            startingColumnNumber = "9223372036854775807"
+            endingColumnNumber = "9223372036854775807"
+            startingLineNumber = "51"
+            endingLineNumber = "51"
+            landmarkName = "testStringList()"
+            landmarkType = "7">
+         </BreakpointContent>
+      </BreakpointProxy>
+      <BreakpointProxy
+         BreakpointExtensionID = "Xcode.Breakpoint.FileBreakpoint">
+         <BreakpointContent
+            shouldBeEnabled = "Yes"
+            ignoreCount = "0"
+            continueAfterRunningActions = "No"
+            filePath = "SwiftTests/ListTest.swift"
+            timestampString = "490838496.854884"
+            startingColumnNumber = "9223372036854775807"
+            endingColumnNumber = "9223372036854775807"
+            startingLineNumber = "34"
+            endingLineNumber = "34"
+            landmarkName = "testStringList()"
+            landmarkType = "7">
+         </BreakpointContent>
+      </BreakpointProxy>
    </Breakpoints>
 </Bucket>

SwiftTests/ListTest.swift

@@ -24,28 +24,29 @@ class ListTest: XCTestCase {
 
 
         /*
-         note: each element has its own corresponding "slot" in the
-         hash list with the exception of hash "collisions".
+         note: each element has its own potential 'slot' in the
+         hash list. In this scenario, the hash table algorithm will
+         implement 'separate chaining' to support 'hash collisions'.
          */
 
 
         //new string list
-        let slist = HashList<String>(capacity: 25)
+        let slist = HashList<String>(capacity: 3)
 
 
-        _ = slist.append("Wayne Bishop", key: "Wayne")
-        _ = slist.append("Frank Smith", key: "Frank")
-        _ = slist.append("Jennifer Hobbs", key: "Jennifer")
-        _ = slist.append("Tim Cook", key: "Tim")
-        _ = slist.append("Steve Jobs", key: "Steve")
-        _ = slist.append("Wayne Bishop", key: "Wayne") //should produce collision
-        _ = slist.append("Larry Page", key: "Larry")
-        _ = slist.append("Albert Einstien", key: "Albert")
+        _ = slist.append("Wayne Bishop")
+        _ = slist.append("Frank Smith")
+        _ = slist.append("Jennifer Hobbs")
+        _ = slist.append("Tim Cook")
+        _ = slist.append("Steve Jobs")
+        _ = slist.append("Wayne Bishop") //should produce collision
+        _ = slist.append("Larry Page")
+        _ = slist.append("Albert Einstien")
 
 
 
         //obtain element
-        let element = slist.getElement(with: "Larry")
+        let element = slist.getElement(with: "Frank Smith")
 
         if let results = element.0 {
             let rString: String? = results.element
@@ -74,7 +75,7 @@ class ListTest: XCTestCase {
         testVertex.key = "A"
 
         let vList: HashList = HashList<Vertex>(capacity: 10)
-       _ = vList.append(testVertex, key: testVertex.key!)
+       _ = vList.append(testVertex)
 
 
 
@@ -100,8 +101,8 @@ class ListTest: XCTestCase {
         //new float list
         let fList = HashList<Float>(capacity: 5)
 
-        _ = fList.append(10.2, key: String(10.2))
-        _ = fList.append(8.6, key: String(8.6))
+        _ = fList.append(10.2)
+        _ = fList.append(8.6)
 
 
         //element doesn't exist..