Conformed Failable<Collection, T> type to Collection protocol

Sources/Validation/Failable+Helpers/Failable+Collection.swift

@@ -0,0 +1,29 @@
+extension Failable: Collection where T: Collection {
+    
+    /// See [`Collection.SubSequence`](https://developer.apple.com/documentation/swift/collection/1641276-subsequence)
+    public typealias SubSequence = T.SubSequence
+    
+    /// See [`Collection.Index`](https://developer.apple.com/documentation/swift/collection/2943866-index).
+    public typealias Index = T.Index
+    
+    /// See [`Collection.startIndex`](https://developer.apple.com/documentation/swift/collection/2946080-startindex).
+    public var startIndex: T.Index {
+        return self.value.startIndex
+    }
+    
+    /// See [`Collection.endIndex`](https://developer.apple.com/documentation/swift/collection/2944204-endindex).
+    public var endIndex: T.Index {
+        return self.value.endIndex
+    }
+    
+    /// See [`Collection.[]`](https://developer.apple.com/documentation/swift/collection/1641358-subscript).
+    public subscript(position: Index) -> Element {
+        return self.value[position]
+    }
+    
+    /// See [`Collection.index(after:)`](https://developer.apple.com/documentation/swift/collection/2943746-index).
+    public func index(after i: T.Index) -> T.Index {
+        return self.value.index(after: i)
+    }
+}
+

Sources/Validation/Failable+Helpers/Failable+Sequence.swift

@@ -10,4 +10,41 @@ extension Failable: Sequence where T: Sequence {
     public func makeIterator() -> T.Iterator {
         return self.value.makeIterator()
     }
+    
+    /// See [`Sequence.split(separator:maxSplits:omittingEmptySubsequences:)`](https://developer.apple.com/documentation/swift/sequence/2908109-split).
+    public func split(maxSplits: Int, omittingEmptySubsequences: Bool, whereSeparator isSeparator: (T.Element) throws -> Bool) rethrows
+        -> [T.SubSequence]
+    {
+        return try self.value.split(maxSplits: maxSplits, omittingEmptySubsequences: omittingEmptySubsequences, whereSeparator: isSeparator)
+    }
+    
+    /// See [`Sequence.suffix(_:)`](https://developer.apple.com/documentation/swift/sequence/2965540-suffix).
+    public func suffix(_ maxLength: Int) -> T.SubSequence {
+        return self.value.suffix(maxLength)
+    }
+    
+    /// See [`Sequence.prefix(while:)`](https://developer.apple.com/documentation/swift/sequence/2965528-prefix)
+    public func prefix(while predicate: (T.Element) throws -> Bool) rethrows -> T.SubSequence {
+        return try self.value.prefix(while: predicate)
+    }
+    
+    /// See [`Sequence.prefix(_:)`](https://developer.apple.com/documentation/swift/sequence/2965524-prefix).
+    public func prefix(_ maxLength: Int) -> T.SubSequence {
+        return self.value.prefix(maxLength)
+    }
+    
+    /// See [`Sequence.drop(while:)`](https://developer.apple.com/documentation/swift/sequence/2965501-drop).
+    public func drop(while predicate: (T.Element) throws -> Bool) rethrows -> T.SubSequence {
+        return try self.value.drop(while: predicate)
+    }
+    
+    /// See [`Sequence.dropLast`](https://developer.apple.com/documentation/swift/sequence/2965508-droplast).
+    public func dropLast(_ k: Int) -> T.SubSequence {
+        return self.value.dropLast(k)
+    }
+    
+    /// See [`Sequence.dropFirst(_:)`](https://developer.apple.com/documentation/swift/sequence/2965504-dropfirst).
+    public func dropFirst(_ k: Int) -> T.SubSequence {
+        return self.value.dropFirst(k)
+    }
 }