1 files changed, 147 insertions, 0 deletions
diff --git a/Sources/SwiftChessNeo/Rank.swift b/Sources/SwiftChessNeo/Rank.swift
new file mode 100644
index 0000000..9998e41
--- /dev/null
+++ b/Sources/SwiftChessNeo/Rank.swift
@@ -0,0 +1,147 @@
+//
+//  Rank.swift
+//  Sage
+//
+//  Copyright 2016-2017 Nikolai Vazquez
+//  Modified by SuperGeroy
+//
+//  Licensed under the Apache License, Version 2.0 (the "License");
+//  you may not use this file except in compliance with the License.
+//  You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+//  Unless required by applicable law or agreed to in writing, software
+//  distributed under the License is distributed on an "AS IS" BASIS,
+//  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+//  See the License for the specific language governing permissions and
+//  limitations under the License.
+//
+
+/// A chess board rank.
+///
+/// `Rank`s refer to the eight rows of a chess board, beginning with 1 at the bottom and ending with 8 at the top.
+public enum Rank: Int, Comparable, CustomStringConvertible {
+
+    /// A direction in rank.
+    public enum Direction {
+
+        /// Up direction.
+        case up
+
+        /// Down direction.
+        case down
+
+    }
+
+    /// Rank 1.
+    case one = 1
+
+    /// Rank 2.
+    case two = 2
+
+    /// Rank 3.
+    case three = 3
+
+    /// Rank 4.
+    case four = 4
+
+    /// Rank 5.
+    case five = 5
+
+    /// Rank 6.
+    case six = 6
+
+    /// Rank 7.
+    case seven = 7
+
+    /// Rank 8.
+    case eight = 8
+
+}
+
+extension Rank {
+
+    /// An array of all ranks.
+    public static let all: [Rank] = [1, 2, 3, 4, 5, 6, 7, 8]
+
+    /// The row index of `self`.
+    public var index: Int {
+        return rawValue - 1
+    }
+
+    /// A textual representation of `self`.
+    public var description: String {
+        return String(rawValue)
+    }
+
+    /// Create an instance from an integer value.
+    public init?(_ value: Int) {
+        self.init(rawValue: value)
+    }
+
+    /// Create a `Rank` from a zero-based row index.
+    public init?(index: Int) {
+        self.init(rawValue: index + 1)
+    }
+
+    /// Creates the starting `Rank` for the color.
+    public init(startFor color: Color) {
+        self = color.isWhite ? 1 : 8
+    }
+
+    /// Creates the ending `Rank` for the color.
+    public init(endFor color: Color) {
+        self = color.isWhite ? 8 : 1
+    }
+
+    /// Returns a rank from advancing `self` by `value` with respect to `color`.
+    public func advanced(by value: Int, for color: Color = .white) -> Rank? {
+        return Rank(rawValue: rawValue + (color.isWhite ? value : -value))
+    }
+
+    /// The next rank after `self`.
+    public func next() -> Rank? {
+        return Rank(rawValue: (rawValue + 1))
+    }
+
+    /// The previous rank to `self`.
+    public func previous() -> Rank? {
+        return Rank(rawValue: (rawValue - 1))
+    }
+
+    /// The opposite rank of `self`.
+    public func opposite() -> Rank {
+        return Rank(rawValue: 9 - rawValue)!
+    }
+
+    /// The files from `self` to `other`.
+    public func to(_ other: Rank) -> [Rank] {
+        return _to(other)
+    }
+
+    /// The files between `self` and `other`.
+    public func between(_ other: Rank) -> [Rank] {
+        return _between(other)
+    }
+
+}
+
+extension Rank: ExpressibleByIntegerLiteral { }
+
+extension Rank {
+
+    /// Create an instance initialized to `value`.
+    public init(integerLiteral value: Int) {
+        guard let rank = Rank(rawValue: value) else {
+            fatalError("Rank value not within 1 and 8, inclusive")
+        }
+        self = rank
+    }
+
+}
+
+/// Returns `true` if one rank is higher than the other.
+public func < (lhs: Rank, rhs: Rank) -> Bool {
+    return lhs.rawValue < rhs.rawValue
+}