Split tags into separate files

Sources/ForTag.swift

@@ -0,0 +1,62 @@
+public class ForNode : NodeType {
+  let variable:Variable
+  let loopVariable:String
+  let nodes:[NodeType]
+  let emptyNodes: [NodeType]
+
+  public class func parse(parser:TokenParser, token:Token) throws -> NodeType {
+    let components = token.components()
+
+    guard components.count == 4 && components[2] == "in" else {
+      throw TemplateSyntaxError("'for' statements should use the following 'for x in y' `\(token.contents)`.")
+    }
+
+    let loopVariable = components[1]
+    let variable = components[3]
+
+    var emptyNodes = [NodeType]()
+
+    let forNodes = try parser.parse(until(["endfor", "empty"]))
+
+    guard let token = parser.nextToken() else {
+      throw TemplateSyntaxError("`endfor` was not found.")
+    }
+
+    if token.contents == "empty" {
+      emptyNodes = try parser.parse(until(["endfor"]))
+      parser.nextToken()
+    }
+
+    return ForNode(variable: variable, loopVariable: loopVariable, nodes: forNodes, emptyNodes:emptyNodes)
+  }
+
+  public init(variable:String, loopVariable:String, nodes:[NodeType], emptyNodes:[NodeType]) {
+    self.variable = Variable(variable)
+    self.loopVariable = loopVariable
+    self.nodes = nodes
+    self.emptyNodes = emptyNodes
+  }
+
+  public func render(context: Context) throws -> String {
+    let values = try variable.resolve(context)
+
+    if let values = values as? [Any] where values.count > 0 {
+      let count = values.count
+      return try values.enumerate().map { index, item in
+        let forContext: [String: Any] = [
+          "first": index == 0,
+          "last": index == (count - 1),
+          "counter": index + 1,
+        ]
+
+        return try context.push([loopVariable: item, "forloop": forContext]) {
+          try renderNodes(nodes, context)
+        }
+      }.joinWithSeparator("")
+    }
+
+    return try context.push {
+      try renderNodes(emptyNodes, context)
+    }
+  }
+}