Terms unification & copypaste bugfix

Model/Sources/Model/Board.swift

@@ -1,11 +1,11 @@
 public struct Board {
-	var grid: [[Piece?]]
+	private var grid: [[Piece?]]
     
-    public var width: Int { return grid.count }
+    public var columns: Int { return grid.count }
-    public var height: Int { return grid.first!.count }
+    public var rows: Int { return grid.first!.count }
 
-    public init?(width: Int, height: Int) {
+    public init?(columns: Int, rows: Int) {
-        self.init(grid: Array(repeating: Array(repeating: nil, count: height), count: width))
+        self.init(grid: Array(repeating: Array(repeating: nil, count: rows), count: columns))
 	}
 
 	public init?(grid: [[Piece?]]) {
@@ -17,10 +17,10 @@ public struct Board {
 	}
     
     private func checkBounds(_ column: Int, _ row: Int) {
-        precondition(column >= 0 && column < self.width && row >= 0 && row < self.height, "Coordinates out of bounds")
+        precondition(column >= 0 && column < self.columns && row >= 0 && row < self.rows, "Coordinates out of bounds")
     }
     
-    subscript(column: Int, row: Int) -> Piece? {
+    public subscript(column: Int, row: Int) -> Piece? {
         get {
             checkBounds(column, row)
             return grid[column][row]
@@ -60,12 +60,13 @@ public struct Board {
         return count
     }
     
+    @discardableResult
     public mutating func insert(piece: Piece, side: Side = .Top, offset: Int, pushing push: Bool = false) -> Bool {
         precondition(offset >= 0, "Offset out of bounds")
         
         switch side {
         case .Top:
-            precondition(offset < self.width, "Offset (column) out of bounds")
+            precondition(offset < self.columns, "Offset (column) out of bounds")
             
             if self.grid[offset].first! != nil {
                 if (!push) {
@@ -79,21 +80,21 @@ public struct Board {
             
             return true
         case .Left:
-            precondition(offset < self.height, "Offset (row) out of bounds")
+            precondition(offset < self.rows, "Offset (row) out of bounds")
             
             if self.grid.first![offset] != nil {
                 if (!push) {
                     return false
                 }
                 
-                self.shiftLeft(row: offset)
+                self.shiftRight(row: offset)
             }
             
             self.grid[0][offset] = piece
             
             return true
         case .Bottom:
-            precondition(offset < self.width, "Offset (column) out of bounds")
+            precondition(offset < self.columns, "Offset (column) out of bounds")
             
             if self.grid[offset].last! != nil {
                 if (!push) {
@@ -108,7 +109,7 @@ public struct Board {
             
             return true
         case .Right:
-            precondition(offset < self.height, "Offset (row) out of bounds")
+            precondition(offset < self.rows, "Offset (row) out of bounds")
             
             if self.grid.last![offset] != nil {
                 if (!push) {
@@ -118,8 +119,7 @@ public struct Board {
                 self.shiftLeft(row: offset)
             }
             
-            let lastIndex = self.grid[offset].count - 1
+            self.grid[self.columns - 1][offset] = piece
-            self.grid[offset][lastIndex] = piece
             
             return true
         }