Add Package.swift and move files around

Sources/Inheritence.swift

@@ -0,0 +1,114 @@
+class BlockContext {
+  class var contextKey: String { return "block_context" }
+
+  var blocks: [String:BlockNode]
+
+  init(blocks: [String:BlockNode]) {
+    self.blocks = blocks
+  }
+
+  func pop(blockName: String) -> BlockNode? {
+    return blocks.removeValueForKey(blockName)
+  }
+}
+
+
+extension CollectionType {
+  func any(closure: Generator.Element -> Bool) -> Generator.Element? {
+    for element in self {
+      if closure(element) {
+        return element
+      }
+    }
+
+    return nil
+  }
+}
+
+
+class ExtendsNode : NodeType {
+  let templateName: Variable
+  let blocks: [String:BlockNode]
+
+  class func parse(parser: TokenParser, token: Token) throws -> NodeType {
+    let bits = token.components()
+
+    guard bits.count == 2 else {
+      throw TemplateSyntaxError("'extends' takes one argument, the template file to be extended")
+    }
+
+    let parsedNodes = try parser.parse()
+    guard (parsedNodes.any { $0 is ExtendsNode }) == nil else {
+      throw TemplateSyntaxError("'extends' cannot appear more than once in the same template")
+    }
+
+    let blockNodes = parsedNodes.filter { node in node is BlockNode }
+
+    let nodes = blockNodes.reduce([String:BlockNode]()) { (accumulator, node:NodeType) -> [String:BlockNode] in
+      let node = (node as! BlockNode)
+      var dict = accumulator
+      dict[node.name] = node
+      return dict
+    }
+
+    return ExtendsNode(templateName: Variable(bits[1]), blocks: nodes)
+  }
+
+  init(templateName: Variable, blocks: [String: BlockNode]) {
+    self.templateName = templateName
+    self.blocks = blocks
+  }
+
+  func render(context: Context) throws -> String {
+    guard let loader = context["loader"] as? TemplateLoader else {
+      throw TemplateSyntaxError("Template loader not in context")
+    }
+
+    guard let templateName = try self.templateName.resolve(context) as? String else {
+      throw TemplateSyntaxError("'\(self.templateName)' could not be resolved as a string")
+    }
+
+    guard let template = loader.loadTemplate(templateName) else {
+      let paths:String = loader.paths.map { $0.description }.joinWithSeparator(", ")
+      throw TemplateSyntaxError("'\(templateName)' template not found in \(paths)")
+    }
+
+    let blockContext = BlockContext(blocks: blocks)
+    context.push([BlockContext.contextKey: blockContext])
+    let result = try template.render(context)
+    context.pop()
+    return result
+  }
+}
+
+
+class BlockNode : NodeType {
+  let name: String
+  let nodes: [NodeType]
+
+  class func parse(parser: TokenParser, token: Token) throws -> NodeType {
+    let bits = token.components()
+
+    guard bits.count == 2 else {
+      throw TemplateSyntaxError("'block' tag takes one argument, the template file to be included")
+    }
+
+    let blockName = bits[1]
+    let nodes = try parser.parse(until(["endblock"]))
+    parser.nextToken()
+    return BlockNode(name:blockName, nodes:nodes)
+  }
+
+  init(name: String, nodes: [NodeType]) {
+    self.name = name
+    self.nodes = nodes
+  }
+
+  func render(context: Context) throws -> String {
+    if let blockContext = context[BlockContext.contextKey] as? BlockContext, node = blockContext.pop(name) {
+      return try node.render(context)
+    }
+
+    return try renderNodes(nodes, context)
+  }
+}