Merge branch 'master' into errors-logs-improvements

Sources/Variable.swift

@@ -48,8 +48,10 @@ public struct Variable : Equatable, Resolvable {
     self.variable = variable
   }
 
-  fileprivate func lookup() -> [String] {
-    return variable.characters.split(separator: ".").map(String.init)
+  // Split the lookup string and resolve references if possible
+  fileprivate func lookup(_ context: Context) throws -> [String] {
+    var keyPath = KeyPath(variable, in: context)
+    return try keyPath.parse()
   }
 
   /// Resolve the variable in the given context
@@ -68,8 +70,12 @@ public struct Variable : Equatable, Resolvable {
     if let number = Number(variable) {
       return number
     }
+    // Boolean literal
+    if let bool = Bool(variable) {
+      return bool
+    }
 
-    for bit in lookup() {
+    for bit in try lookup(context) {
       current = normalize(current)
 
       if let context = current as? Context {
@@ -124,6 +130,42 @@ public func ==(lhs: Variable, rhs: Variable) -> Bool {
   return lhs.variable == rhs.variable
 }
 
+/// A structure used to represet range of two integer values expressed as `from...to`.
+/// Values should be numbers (they will be converted to integers).
+/// Rendering this variable produces array from range `from...to`.
+/// If `from` is more than `to` array will contain values of reversed range.
+public struct RangeVariable: Resolvable {
+  public let from: Resolvable
+  public let to: Resolvable
+
+  public init?(_ token: String, parser: TokenParser) throws {
+    let components = token.components(separatedBy: "...")
+    guard components.count == 2 else {
+      return nil
+    }
+
+    self.from = try parser.compileFilter(components[0])
+    self.to = try parser.compileFilter(components[1])
+  }
+
+  public func resolve(_ context: Context) throws -> Any? {
+    let fromResolved = try from.resolve(context)
+    let toResolved = try to.resolve(context)
+
+    guard let from = fromResolved.flatMap(toNumber(value:)).flatMap(Int.init) else {
+      throw TemplateSyntaxError("'from' value is not an Integer (\(fromResolved ?? "nil"))")
+    }
+
+    guard let to = toResolved.flatMap(toNumber(value:)).flatMap(Int.init) else {
+      throw TemplateSyntaxError("'to' value is not an Integer (\(toResolved ?? "nil") )")
+    }
+
+    let range = min(from, to)...max(from, to)
+    return from > to ? Array(range.reversed()) : Array(range)
+  }
+
+}
+
 
 func normalize(_ current: Any?) -> Any? {
   if let current = current as? Normalizable {
@@ -167,25 +209,47 @@ extension Dictionary : Normalizable {
 
 func parseFilterComponents(token: String) -> (String, [Variable]) {
   var components = token.smartSplit(separator: ":")
-  let name = components.removeFirst()
+  let name = components.removeFirst().trim(character: " ")
   let variables = components
     .joined(separator: ":")
     .smartSplit(separator: ",")
-    .map { Variable($0) }
+    .map { Variable($0.trim(character: " ")) }
   return (name, variables)
 }
 
 extension Mirror {
   func getValue(for key: String) -> Any? {
-    let result = descendant(key)
+    let result = descendant(key) ?? Int(key).flatMap({ descendant($0) })
     if result == nil {
       // go through inheritance chain to reach superclass properties
       return superclassMirror?.getValue(for: key)
-    } else if let result = result, String(describing: result) == "nil" {
-      // mirror returns non-nil value even for nil-containing properties
-      // so we have to check if its value is actually nil or not
-      return nil
+    } else if let result = result {
+      guard String(describing: result) != "nil" else {
+        // mirror returns non-nil value even for nil-containing properties
+        // so we have to check if its value is actually nil or not
+        return nil
+      }
+      if let result = (result as? AnyOptional)?.wrapped {
+        return result
+      } else {
+        return result
+      }
     }
     return result
   }
 }
+
+protocol AnyOptional {
+  var wrapped: Any? { get }
+}
+
+extension Optional: AnyOptional {
+  var wrapped: Any? {
+    switch self {
+    case let .some(value): return value
+    case .none: return nil
+    }
+  }
+}
+
+