chore: Release 0.7.0

Closes #70

.swift-version

@@ -1 +1 @@
-DEVELOPMENT-SNAPSHOT-2016-01-25-a
+3.0.1

.travis.yml

@@ -1,11 +1,11 @@
 os:
-  - osx
-  - linux
+- osx
+- linux
 language: generic
 sudo: required
 dist: trusty
-osx_image: xcode7.2
+osx_image: xcode8
 install:
-  - eval "$(curl -sL https://gist.githubusercontent.com/kylef/5c0475ff02b7c7671d2a/raw/02090c7ede5a637b76e6df1710e83cd0bbe7dcdf/swiftenv-install.sh)"
+- eval "$(curl -sL https://gist.githubusercontent.com/kylef/5c0475ff02b7c7671d2a/raw/9f442512a46d7a2af7b850d65a7e9bd31edfb09b/swiftenv-install.sh)"
 script:
-- make test
+- swift test

CHANGELOG.md

@@ -0,0 +1,67 @@
+# Stencil Changelog
+
+## 0.7.0
+
+### Breaking
+
+- `TemplateLoader` has been renamed to `FileSystemLoader`. The
+  `loadTemplate(s)` methods are now throwing and now take labels for the `name`
+  and `names` arguments.
+
+- Many internal classes are no longer public. Some APIs were previously
+  accessible due to earlier versions of Swift requiring the types to be public
+  to be able to test. Now we have access to `@testable` these can correctly be
+  private.
+
+- `{% ifnot %}` tag is now deprecated, please use `{% if not %}` instead.
+
+### Enhancements
+
+- Variable lookup now supports introspection of Swift types. You can now lookup
+  values of Swift structures and classes inside a Context.
+
+- If tags can now use prefix and infix operators such as `not`, `and`, `or`,
+  `==`, `!=`, `>`, `>=`, `<` and `<=`.
+
+    ```html+django
+    {% if one or two and not three %}
+    ```
+
+- You may now register custom template filters which make use of arguments.
+- There is now a `default` filter.
+
+    ```html+django
+    Hello {{ name|default:"World" }}
+    ```
+
+- There is now a `join` filter.
+
+    ```html+django
+    {{ value|join:", " }}
+    ```
+
+- `{% for %}` tag now supports filters.
+
+    ```html+django
+    {% for user in non_admins|default:admins %}
+      {{ user }}
+    {% endfor %}
+    ```
+
+### Bug Fixes
+
+- Variables (`{{ variable.5 }}`) that reference an array index at an unknown
+  index will now resolve to `nil` instead of causing a crash.
+  [#72](https://github.com/kylef/Stencil/issues/72)
+
+- Templates can now extend templates that extend other templates.
+  [#60](https://github.com/kylef/Stencil/issues/60)
+
+- If comparisons will now treat 0 and below numbers as negative.
+
+
+## 0.6.0
+
+### Enhancements
+
+- Adds support for Swift 3.0.

Makefile

@@ -1,7 +0,0 @@
-stencil:
-	@echo "Building Stencil"
-	@swift build
-
-test: stencil
-	@echo "Running Tests"
-	@.build/debug/spectre-build

Package.swift

@@ -3,9 +3,9 @@ import PackageDescription
 let package = Package(
   name: "Stencil",
   dependencies: [
-    .Package(url: "https://github.com/kylef/PathKit.git", majorVersion: 0, minor: 6),
-  ],
-  testDependencies: [
-    .Package(url: "https://github.com/kylef/spectre-build", majorVersion: 0),
+    .Package(url: "https://github.com/kylef/PathKit.git", majorVersion: 0, minor: 7),
+
+    // https://github.com/apple/swift-package-manager/pull/597
+    .Package(url: "https://github.com/kylef/Spectre", majorVersion: 0, minor: 7),
   ]
 )

README.md

@@ -11,21 +11,28 @@ feel right at home with Stencil.
 ```html+django
 There are {{ articles.count }} articles.
 
-{% for article in articles %}
-  - {{ article.title }} by {{ article.author }}.
-{% endfor %}
+<ul>
+  {% for article in articles %}
+    <li>{{ article.title }} by {{ article.author }}</li>
+  {% endfor %}
+</ul>
 ```
 
 ```swift
+struct Article {
+  let title: String
+  let author: String
+}
+
 let context = Context(dictionary: [
   "articles": [
-    [ "title": "Migrating from OCUnit to XCTest", "author": "Kyle Fuller" ],
-    [ "title": "Memory Management with ARC", "author": "Kyle Fuller" ],
+    Article(title: "Migrating from OCUnit to XCTest", author: "Kyle Fuller"),
+    Article(title: "Memory Management with ARC", author: "Kyle Fuller"),
   ]
 ])
 
 do {
-  let template = try Template(named: "template.stencil")
+  let template = try Template(named: "template.html")
   let rendered = try template.render(context)
   print(rendered)
 } catch {
@@ -35,7 +42,9 @@ do {
 
 ## Installation
 
-Installation with CocoaPods is recommended.
+Installation with Swift Package Manager is recommended.
+
+### CocoaPods
 
 ```ruby
 pod 'Stencil'
@@ -51,191 +60,11 @@ Stencil follows the same philosophy of Django:
 > design: the template system is meant to express presentation, not program
 > logic.
 
-## Templates
+## The User Guide
 
-### Variables
-
-A variable can be defined in your template using the following:
-
-```html+django
-{{ variable }}
-```
-
-Stencil will look up the variable inside the current variable context and
-evaluate it. When a variable contains a dot, it will try doing the
-following lookup:
-
-- Context lookup
-- Dictionary lookup
-- Array lookup (first, last, count, index)
-- Key value coding lookup
-
-For example, if `people` was an array:
-
-```html+django
-There are {{ people.count }} people. {{ people.first }} is the first person,
-followed by {{ people.1 }}.
-```
-
-#### Filters
-
-Filters allow you to transform the values of variables. For example, they look like:
-
-```html+django
-{{ variable|uppercase }}
-```
-
-##### Capitalize
-
-The capitalize filter allows you to capitalize a string.
-For example, `stencil` to `Stencil`.
-
-```html+django
-{{ "stencil"|capitalize }}
-```
-
-##### Uppercase
-
-The uppercase filter allows you to transform a string to uppercase.
-For example, `Stencil` to `STENCIL`.
-
-```html+django
-{{ "Stencil"|uppercase }}
-```
-
-##### Lowercase
-
-The uppercase filter allows you to transform a string to lowercase.
-For example, `Stencil` to `stencil`.
-
-```html+django
-{{ "Stencil"|lowercase }}
-```
-
-### Tags
-
-Tags are a mechanism to execute a piece of code, allowing you to have
-control flow within your template.
-
-```html+django
-{% if variable %}
-  {{ variable }} was found.
-{% endif %}
-```
-
-A tag can also affect the context and define variables as follows:
-
-```html+django
-{% for item in items %}
-  {{ item }}
-{% endfor %}
-```
-
-Stencil has a couple of built-in tags which are listed below. You can also
-extend Stencil by providing your own tags.
-
-#### for
-
-A for loop allows you to iterate over an array found by variable lookup.
-
-```html+django
-{% for item in items %}
-  {{ item }}
-{% empty %}
-  There were no items.
-{% endfor %}
-```
-
-#### if
-
-```html+django
-{% if variable %}
-  The variable was found in the current context.
-{% else %}
-  The variable was not found.
-{% endif %}
-```
-
-#### ifnot
-
-```html+django
-{% ifnot variable %}
-  The variable was NOT found in the current context.
-{% else %}
-  The variable was found.
-{% endif %}
-```
-
-#### include
-
-You can include another template using the `include` tag.
-
-```html+django
-{% include "comment.html" %}
-```
-
-The `include` tag requires a TemplateLoader to be found inside your context with the paths, or bundles used to lookup the template.
-
-```swift
-let context = Context(dictionary: [
-  "loader": TemplateLoader(bundle:[NSBundle.mainBundle()])
-])
-```
-
-### Customisation
-
-You can build your own custom filters and tags and pass them down while
-rendering your template. Any custom filters or tags must be registered
-with a namespace which contains all filters and tags available to the template.
-
-```swift
-let namespace = Namespace()
-// Register your filters and tags with the namespace
-let rendered = try template.render(context, namespace: namespace)
-```
-
-#### Registering custom filters
-
-```swift
-namespace.registerFilter("double") { value in
-  if let value = value as? Int {
-    return value * 2
-  }
-
-  return value
-}
-```
-
-#### Building custom tags
-
-You can build a custom template tag. There are a couple of APIs to allow
-you to write your own custom tags. The following is the simplest form:
-
-```swift
-namespace.registerSimpleTag("custom") { context in
-  return "Hello World"
-}
-```
-
-When your tag is used via `{% custom %}` it will execute the registered block
-of code allowing you to modify or retrieve a value from the context. Then
-return either a string rendered in your template, or throw an error.
-
-If you want to accept arguments or to capture different tokens between two sets
-of template tags. You will need to call the `registerTag` API which accepts a
-closure to handle the parsing. You can find examples of the `now`, `if` and
-`for` tags found inside `Node.swift`.
-
-The architecture of Stencil along with how to build advanced plugins can be
-found in the [architecture](ARCHITECTURE.md) document.
-
-### Comments
-
-To comment out part of your template, you can use the following syntax:
-
-```html+django
-{# My comment is completely hidden #}
-```
+- [Templates](http://stencil.fuller.li/en/latest/templates.html)
+- [Built-in template tags and filters](http://stencil.fuller.li/en/latest/builtins.html)
+- [Custom Template Tags and Filters](http://stencil.fuller.li/en/latest/custom-template-tags-and-filters.html)
 
 ## License
 

Sources/Context.swift

@@ -1,6 +1,6 @@
 /// A container for template variables.
 public class Context {
-  var dictionaries: [[String: Any]]
+  var dictionaries: [[String: Any?]]
   let namespace: Namespace
 
   /// Initialise a Context with an optional dictionary and optional namespace
@@ -17,7 +17,7 @@ public class Context {
   public subscript(key: String) -> Any? {
     /// Retrieves a variable's value, starting at the current context and going upwards
     get {
-      for dictionary in Array(dictionaries.reverse()) {
+      for dictionary in Array(dictionaries.reversed()) {
         if let value = dictionary[key] {
           return value
         }
@@ -37,19 +37,33 @@ public class Context {
   }
 
   /// Push a new level into the Context
-  private func push(dictionary: [String: Any]? = nil) {
+  fileprivate func push(_ dictionary: [String: Any]? = nil) {
     dictionaries.append(dictionary ?? [:])
   }
 
   /// Pop the last level off of the Context
-  private func pop() -> [String: Any]? {
+  fileprivate func pop() -> [String: Any]? {
     return dictionaries.popLast()
   }
 
   /// Push a new level onto the context for the duration of the execution of the given closure
-  public func push<Result>(dictionary: [String: Any]? = nil, @noescape closure: (() throws -> Result)) rethrows -> Result {
+  public func push<Result>(dictionary: [String: Any]? = nil, closure: (() throws -> Result)) rethrows -> Result {
     push(dictionary)
-    defer { pop() }
+    defer { _ = pop() }
     return try closure()
   }
+
+  public func flatten() -> [String: Any] {
+    var accumulator: [String: Any] = [:]
+
+    for dictionary in dictionaries {
+      for (key, value) in dictionary {
+        if let value = value {
+          accumulator.updateValue(value, forKey: key)
+        }
+      }
+    }
+
+    return accumulator
+  }
 }

Sources/Expression.swift

@@ -0,0 +1,300 @@
+protocol Expression: CustomStringConvertible {
+  func evaluate(context: Context) throws -> Bool
+}
+
+
+protocol InfixOperator: Expression {
+  init(lhs: Expression, rhs: Expression)
+}
+
+
+protocol PrefixOperator: Expression {
+  init(expression: Expression)
+}
+
+
+final class StaticExpression: Expression, CustomStringConvertible {
+  let value: Bool
+
+  init(value: Bool) {
+    self.value = value
+  }
+
+  func evaluate(context: Context) throws -> Bool {
+    return value
+  }
+
+  var description: String {
+    return "\(value)"
+  }
+}
+
+
+final class VariableExpression: Expression, CustomStringConvertible {
+  let variable: Variable
+
+  init(variable: Variable) {
+    self.variable = variable
+  }
+
+  var description: String {
+    return "(variable: \(variable.variable))"
+  }
+
+  /// Resolves a variable in the given context as boolean
+  func resolve(context: Context, variable: Variable) throws -> Bool {
+    let result = try variable.resolve(context)
+    var truthy = false
+
+    if let result = result as? [Any] {
+      truthy = !result.isEmpty
+    } else if let result = result as? [String:Any] {
+      truthy = !result.isEmpty
+    } else if let result = result as? Bool {
+      truthy = result
+    } else if let result = result as? String {
+      truthy = !result.isEmpty
+    } else if let value = result, let result = toNumber(value: value) {
+      truthy = result > 0
+    } else if result != nil {
+      truthy = true
+    }
+
+    return truthy
+  }
+
+  func evaluate(context: Context) throws -> Bool {
+    return try resolve(context: context, variable: variable)
+  }
+}
+
+
+final class NotExpression: Expression, PrefixOperator, CustomStringConvertible {
+  let expression: Expression
+
+  init(expression: Expression) {
+    self.expression = expression
+  }
+
+  var description: String {
+    return "not \(expression)"
+  }
+
+  func evaluate(context: Context) throws -> Bool {
+    return try !expression.evaluate(context: context)
+  }
+}
+
+
+final class OrExpression: Expression, InfixOperator, CustomStringConvertible {
+  let lhs: Expression
+  let rhs: Expression
+
+  init(lhs: Expression, rhs: Expression) {
+    self.lhs = lhs
+    self.rhs = rhs
+  }
+
+  var description: String {
+    return "(\(lhs) or \(rhs))"
+  }
+
+  func evaluate(context: Context) throws -> Bool {
+    let lhs = try self.lhs.evaluate(context: context)
+    if lhs {
+      return lhs
+    }
+
+    return try rhs.evaluate(context: context)
+  }
+}
+
+
+final class AndExpression: Expression, InfixOperator, CustomStringConvertible {
+  let lhs: Expression
+  let rhs: Expression
+
+  init(lhs: Expression, rhs: Expression) {
+    self.lhs = lhs
+    self.rhs = rhs
+  }
+
+  var description: String {
+    return "(\(lhs) and \(rhs))"
+  }
+
+  func evaluate(context: Context) throws -> Bool {
+    let lhs = try self.lhs.evaluate(context: context)
+    if !lhs {
+      return lhs
+    }
+
+    return try rhs.evaluate(context: context)
+  }
+}
+
+
+class EqualityExpression: Expression, InfixOperator, CustomStringConvertible {
+  let lhs: Expression
+  let rhs: Expression
+
+  required init(lhs: Expression, rhs: Expression) {
+    self.lhs = lhs
+    self.rhs = rhs
+  }
+
+  var description: String {
+    return "(\(lhs) == \(rhs))"
+  }
+
+  func evaluate(context: Context) throws -> Bool {
+    if let lhs = lhs as? VariableExpression, let rhs = rhs as? VariableExpression {
+      let lhsValue = try lhs.variable.resolve(context)
+      let rhsValue = try rhs.variable.resolve(context)
+
+      if let lhs = lhsValue, let rhs = rhsValue {
+        if let lhs = toNumber(value: lhs), let rhs = toNumber(value: rhs) {
+          return lhs == rhs
+        } else if let lhs = lhsValue as? String, let rhs = rhsValue as? String {
+          return lhs == rhs
+        } else if let lhs = lhsValue as? Bool, let rhs = rhsValue as? Bool {
+          return lhs == rhs
+        }
+      } else if lhsValue == nil && rhsValue == nil {
+        return true
+      }
+    }
+
+    return false
+  }
+}
+
+
+class NumericExpression: Expression, InfixOperator, CustomStringConvertible {
+  let lhs: Expression
+  let rhs: Expression
+
+  required init(lhs: Expression, rhs: Expression) {
+    self.lhs = lhs
+    self.rhs = rhs
+  }
+
+  var description: String {
+    return "(\(lhs) \(op) \(rhs))"
+  }
+
+  func evaluate(context: Context) throws -> Bool {
+    if let lhs = lhs as? VariableExpression, let rhs = rhs as? VariableExpression {
+      let lhsValue = try lhs.variable.resolve(context)
+      let rhsValue = try rhs.variable.resolve(context)
+
+      if let lhs = lhsValue, let rhs = rhsValue {
+        if let lhs = toNumber(value: lhs), let rhs = toNumber(value: rhs) {
+          return compare(lhs: lhs, rhs: rhs)
+        }
+      }
+    }
+
+    return false
+  }
+
+  var op: String {
+    return ""
+  }
+
+  func compare(lhs: Float80, rhs: Float80) -> Bool {
+    return false
+  }
+}
+
+
+class MoreThanExpression: NumericExpression {
+  override var op: String {
+    return ">"
+  }
+
+  override func compare(lhs: Float80, rhs: Float80) -> Bool {
+    return lhs > rhs
+  }
+}
+
+
+class MoreThanEqualExpression: NumericExpression {
+  override var op: String {
+    return ">="
+  }
+
+  override func compare(lhs: Float80, rhs: Float80) -> Bool {
+    return lhs >= rhs
+  }
+}
+
+
+class LessThanExpression: NumericExpression {
+  override var op: String {
+    return "<"
+  }
+
+  override func compare(lhs: Float80, rhs: Float80) -> Bool {
+    return lhs < rhs
+  }
+}
+
+
+class LessThanEqualExpression: NumericExpression {
+  override var op: String {
+    return "<="
+  }
+
+  override func compare(lhs: Float80, rhs: Float80) -> Bool {
+    return lhs <= rhs
+  }
+}
+
+
+class InequalityExpression: EqualityExpression {
+  override var description: String {
+    return "(\(lhs) != \(rhs))"
+  }
+
+  override func evaluate(context: Context) throws -> Bool {
+    return try !super.evaluate(context: context)
+  }
+}
+
+
+func toNumber(value: Any) -> Float80? {
+    if let value = value as? Float {
+        return Float80(value)
+    } else if let value = value as? Double {
+        return Float80(value)
+    } else if let value = value as? UInt {
+        return Float80(value)
+    } else if let value = value as? Int {
+        return Float80(value)
+    } else if let value = value as? Int8 {
+        return Float80(value)
+    } else if let value = value as? Int16 {
+        return Float80(value)
+    } else if let value = value as? Int32 {
+        return Float80(value)
+    } else if let value = value as? Int64 {
+        return Float80(value)
+    } else if let value = value as? UInt8 {
+        return Float80(value)
+    } else if let value = value as? UInt16 {
+        return Float80(value)
+    } else if let value = value as? UInt32 {
+        return Float80(value)
+    } else if let value = value as? UInt64 {
+        return Float80(value)
+    } else if let value = value as? Float80 {
+        return value
+    } else if let value = value as? Float64 {
+        return Float80(value)
+    } else if let value = value as? Float32 {
+        return Float80(value)
+    }
+
+    return nil
+}

Sources/Filters.swift

@@ -1,4 +1,4 @@
-func toString(value: Any?) -> String? {
+func toString(_ value: Any?) -> String? {
   if let value = value as? String {
     return value
   } else if let value = value as? CustomStringConvertible {
@@ -8,26 +8,56 @@ func toString(value: Any?) -> String? {
   return nil
 }
 
-func capitalise(value: Any?) -> Any? {
+func capitalise(_ value: Any?) -> Any? {
   if let value = toString(value) {
-    return value.capitalizedString
+    return value.capitalized
   }
 
   return value
 }
 
-func uppercase(value: Any?) -> Any? {
+func uppercase(_ value: Any?) -> Any? {
   if let value = toString(value) {
-    return value.uppercaseString
+    return value.uppercased()
   }
 
   return value
 }
 
-func lowercase(value: Any?) -> Any? {
+func lowercase(_ value: Any?) -> Any? {
   if let value = toString(value) {
-    return value.lowercaseString
+    return value.lowercased()
   }
 
   return value
 }
+
+func defaultFilter(value: Any?, arguments: [Any?]) -> Any? {
+  if let value = value {
+    return value
+  }
+
+  for argument in arguments {
+    if let argument = argument {
+      return argument
+    }
+  }
+
+  return nil
+}
+
+func joinFilter(value: Any?, arguments: [Any?]) throws -> Any? {
+  guard arguments.count == 1 else {
+    throw TemplateSyntaxError("'join' filter takes a single argument")
+  }
+
+  guard let separator = arguments.first as? String else {
+    throw TemplateSyntaxError("'join' filter takes a separator as string")
+  }
+
+  if let value = value as? [String] {
+    return value.joined(separator: separator)
+  }
+
+  return nil
+}

Sources/ForTag.swift

@@ -1,10 +1,10 @@
-public class ForNode : NodeType {
-  let variable:Variable
+class ForNode : NodeType {
+  let resolvable: Resolvable
   let loopVariable:String
   let nodes:[NodeType]
   let emptyNodes: [NodeType]
 
-  public class func parse(parser:TokenParser, token:Token) throws -> NodeType {
+  class func parse(_ parser:TokenParser, token:Token) throws -> NodeType {
     let components = token.components()
 
     guard components.count == 4 && components[2] == "in" else {
@@ -24,35 +24,36 @@ public class ForNode : NodeType {
 
     if token.contents == "empty" {
       emptyNodes = try parser.parse(until(["endfor"]))
-      parser.nextToken()
+      _ = parser.nextToken()
     }
 
-    return ForNode(variable: variable, loopVariable: loopVariable, nodes: forNodes, emptyNodes:emptyNodes)
+    let filter = try parser.compileFilter(variable)
+    return ForNode(resolvable: filter, loopVariable: loopVariable, nodes: forNodes, emptyNodes:emptyNodes)
   }
 
-  public init(variable:String, loopVariable:String, nodes:[NodeType], emptyNodes:[NodeType]) {
-    self.variable = Variable(variable)
+  init(resolvable: Resolvable, loopVariable:String, nodes:[NodeType], emptyNodes:[NodeType]) {
+    self.resolvable = resolvable
     self.loopVariable = loopVariable
     self.nodes = nodes
     self.emptyNodes = emptyNodes
   }
 
-  public func render(context: Context) throws -> String {
-    let values = try variable.resolve(context)
+  func render(_ context: Context) throws -> String {
+    let values = try resolvable.resolve(context)
 
-    if let values = values as? [Any] where values.count > 0 {
+    if let values = values as? [Any] , values.count > 0 {
       let count = values.count
-      return try values.enumerate().map { index, item in
+      return try values.enumerated().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]) {
+        return try context.push(dictionary: [loopVariable: item, "forloop": forContext]) {
           try renderNodes(nodes, context)
         }
-      }.joinWithSeparator("")
+      }.joined(separator: "")
     }
 
     return try context.push {

Sources/IfTag.swift

@@ -1,14 +1,176 @@
-public class IfNode : NodeType {
-  public let variable:Variable
-  public let trueNodes:[NodeType]
-  public let falseNodes:[NodeType]
+enum Operator {
+  case infix(String, Int, InfixOperator.Type)
+  case prefix(String, Int, PrefixOperator.Type)
 
-  public class func parse(parser:TokenParser, token:Token) throws -> NodeType {
-    let components = token.components()
+  var name: String {
+    switch self {
+    case .infix(let name, _, _):
+      return name
+    case .prefix(let name, _, _):
+      return name
+    }
+  }
+}
+
+
+let operators: [Operator] = [
+  .infix("or", 6, OrExpression.self),
+  .infix("and", 7, AndExpression.self),
+  .prefix("not", 8, NotExpression.self),
+  .infix("==", 10, EqualityExpression.self),
+  .infix("!=", 10, InequalityExpression.self),
+  .infix(">", 10, MoreThanExpression.self),
+  .infix(">=", 10, MoreThanEqualExpression.self),
+  .infix("<", 10, LessThanExpression.self),
+  .infix("<=", 10, LessThanEqualExpression.self),
+]
+
+
+func findOperator(name: String) -> Operator? {
+  for op in operators {
+    if op.name == name {
+      return op
+    }
+  }
+
+  return nil
+}
+
+
+enum IfToken {
+  case infix(name: String, bindingPower: Int, op: InfixOperator.Type)
+  case prefix(name: String, bindingPower: Int, op: PrefixOperator.Type)
+  case variable(Variable)
+  case end
+
+  var bindingPower: Int {
+    switch self {
+    case .infix(_, let bindingPower, _):
+      return bindingPower
+    case .prefix(_, let bindingPower, _):
+      return bindingPower
+    case .variable(_):
+      return 0
+    case .end:
+        return 0
+    }
+  }
+
+  func nullDenotation(parser: IfExpressionParser) throws -> Expression {
+    switch self {
+    case .infix(let name, _, _):
+      throw TemplateSyntaxError("'if' expression error: infix operator '\(name)' doesn't have a left hand side")
+    case .prefix(_, let bindingPower, let op):
+      let expression = try parser.expression(bindingPower: bindingPower)
+      return op.init(expression: expression)
+    case .variable(let variable):
+      return VariableExpression(variable: variable)
+    case .end:
+      throw TemplateSyntaxError("'if' expression error: end")
+    }
+  }
+
+  func leftDenotation(left: Expression, parser: IfExpressionParser) throws -> Expression {
+    switch self {
+    case .infix(_, let bindingPower, let op):
+      let right = try parser.expression(bindingPower: bindingPower)
+      return op.init(lhs: left, rhs: right)
+    case .prefix(let name, _, _):
+      throw TemplateSyntaxError("'if' expression error: prefix operator '\(name)' was called with a left hand side")
+    case .variable(let variable):
+      throw TemplateSyntaxError("'if' expression error: variable '\(variable)' was called with a left hand side")
+    case .end:
+      throw TemplateSyntaxError("'if' expression error: end")
+    }
+  }
+
+  var isEnd: Bool {
+    switch self {
+    case .end:
+      return true
+    default:
+      return false
+    }
+  }
+}
+
+
+final class IfExpressionParser {
+  let tokens: [IfToken]
+  var position: Int = 0
+
+  init(components: [String]) {
+    self.tokens = components.map { component in
+      if let op = findOperator(name: component) {
+        switch op {
+        case .infix(let name, let bindingPower, let cls):
+          return .infix(name: name, bindingPower: bindingPower, op: cls)
+        case .prefix(let name, let bindingPower, let cls):
+          return .prefix(name: name, bindingPower: bindingPower, op: cls)
+        }
+      }
+
+      return .variable(Variable(component))
+    }
+  }
+
+  var currentToken: IfToken {
+    if tokens.count > position {
+      return tokens[position]
+    }
+
+    return .end
+  }
+
+  var nextToken: IfToken {
+    position += 1
+    return currentToken
+  }
+
+  func parse() throws -> Expression {
+    let expression = try self.expression()
+
+    if !currentToken.isEnd {
+      throw TemplateSyntaxError("'if' expression error: dangling token")
+    }
+
+    return expression
+  }
+
+  func expression(bindingPower: Int = 0) throws -> Expression {
+    var token = currentToken
+    position += 1
+
+    var left = try token.nullDenotation(parser: self)
+
+    while bindingPower < currentToken.bindingPower {
+      token = currentToken
+      position += 1
+      left = try token.leftDenotation(left: left, parser: self)
+    }
+
+    return left
+  }
+}
+
+
+func parseExpression(components: [String]) throws -> Expression {
+  let parser = IfExpressionParser(components: components)
+  return try parser.parse()
+}
+
+
+class IfNode : NodeType {
+  let expression: Expression
+  let trueNodes: [NodeType]
+  let falseNodes: [NodeType]
+
+  class func parse(_ parser: TokenParser, token: Token) throws -> NodeType {
+    var components = token.components()
     guard components.count == 2 else {
       throw TemplateSyntaxError("'if' statements should use the following 'if condition' `\(token.contents)`.")
     }
-    let variable = components[1]
+    components.removeFirst()
     var trueNodes = [NodeType]()
     var falseNodes = [NodeType]()
 
@@ -20,18 +182,19 @@ public class IfNode : NodeType {
 
     if token.contents == "else" {
       falseNodes = try parser.parse(until(["endif"]))
-      parser.nextToken()
+      _ = parser.nextToken()
     }
 
-    return IfNode(variable: variable, trueNodes: trueNodes, falseNodes: falseNodes)
+    let expression = try parseExpression(components: components)
+    return IfNode(expression: expression, trueNodes: trueNodes, falseNodes: falseNodes)
   }
 
-  public class func parse_ifnot(parser:TokenParser, token:Token) throws -> NodeType {
-    let components = token.components()
+  class func parse_ifnot(_ parser: TokenParser, token: Token) throws -> NodeType {
+    var components = token.components()
     guard components.count == 2 else {
-      throw TemplateSyntaxError("'ifnot' statements should use the following 'if condition' `\(token.contents)`.")
+      throw TemplateSyntaxError("'ifnot' statements should use the following 'ifnot condition' `\(token.contents)`.")
     }
-    let variable = components[1]
+    components.removeFirst()
     var trueNodes = [NodeType]()
     var falseNodes = [NodeType]()
 
@@ -43,29 +206,21 @@ public class IfNode : NodeType {
 
     if token.contents == "else" {
       trueNodes = try parser.parse(until(["endif"]))
-      parser.nextToken()
+      _ = parser.nextToken()
     }
 
-    return IfNode(variable: variable, trueNodes: trueNodes, falseNodes: falseNodes)
+    let expression = try parseExpression(components: components)
+    return IfNode(expression: expression, trueNodes: trueNodes, falseNodes: falseNodes)
   }
 
-  public init(variable:String, trueNodes:[NodeType], falseNodes:[NodeType]) {
-    self.variable = Variable(variable)
+  init(expression: Expression, trueNodes: [NodeType], falseNodes: [NodeType]) {
+    self.expression = expression
     self.trueNodes = trueNodes
     self.falseNodes = falseNodes
   }
 
-  public func render(context: Context) throws -> String {
-    let result = try variable.resolve(context)
-    var truthy = false
-
-    if let result = result as? [Any] {
-      truthy = !result.isEmpty
-    } else if let result = result as? [String:Any] {
-      truthy = !result.isEmpty
-    } else if result != nil {
-      truthy = true
-    }
+  func render(_ context: Context) throws -> String {
+    let truthy = try expression.evaluate(context: context)
 
     return try context.push {
       if truthy {

Sources/Include.swift

@@ -1,10 +1,10 @@
 import PathKit
 
 
-public class IncludeNode : NodeType {
-  public let templateName: Variable
+class IncludeNode : NodeType {
+  let templateName: Variable
 
-  public class func parse(parser: TokenParser, token: Token) throws -> NodeType {
+  class func parse(_ parser: TokenParser, token: Token) throws -> NodeType {
     let bits = token.components()
 
     guard bits.count == 2 else {
@@ -14,12 +14,12 @@ public class IncludeNode : NodeType {
     return IncludeNode(templateName: Variable(bits[1]))
   }
 
-  public init(templateName: Variable) {
+  init(templateName: Variable) {
     self.templateName = templateName
   }
 
-  public func render(context: Context) throws -> String {
-    guard let loader = context["loader"] as? TemplateLoader else {
+  func render(_ context: Context) throws -> String {
+    guard let loader = context["loader"] as? Loader else {
       throw TemplateSyntaxError("Template loader not in context")
     }
 
@@ -27,9 +27,8 @@ public class IncludeNode : NodeType {
       throw TemplateSyntaxError("'\(self.templateName)' could not be resolved as a string")
     }
 
-    guard let template = loader.loadTemplate(templateName) else {
-      let paths = loader.paths.map { $0.description }.joinWithSeparator(", ")
-      throw TemplateSyntaxError("'\(templateName)' template not found in \(paths)")
+    guard let template = try loader.loadTemplate(name: templateName) else {
+      throw TemplateSyntaxError("'\(templateName)' template not found")
     }
 
     return try template.render(context)

Sources/Inheritence.swift

@@ -1,20 +1,20 @@
 class BlockContext {
   class var contextKey: String { return "block_context" }
 
-  var blocks: [String:BlockNode]
+  var blocks: [String: BlockNode]
 
-  init(blocks: [String:BlockNode]) {
+  init(blocks: [String: BlockNode]) {
     self.blocks = blocks
   }
 
-  func pop(blockName: String) -> BlockNode? {
-    return blocks.removeValueForKey(blockName)
+  func pop(_ blockName: String) -> BlockNode? {
+    return blocks.removeValue(forKey: blockName)
   }
 }
 
 
-extension CollectionType {
-  func any(closure: Generator.Element -> Bool) -> Generator.Element? {
+extension Collection {
+  func any(_ closure: (Iterator.Element) -> Bool) -> Iterator.Element? {
     for element in self {
       if closure(element) {
         return element
@@ -30,7 +30,7 @@ class ExtendsNode : NodeType {
   let templateName: Variable
   let blocks: [String:BlockNode]
 
-  class func parse(parser: TokenParser, token: Token) throws -> NodeType {
+  class func parse(_ parser: TokenParser, token: Token) throws -> NodeType {
     let bits = token.components()
 
     guard bits.count == 2 else {
@@ -42,10 +42,9 @@ class ExtendsNode : NodeType {
       throw TemplateSyntaxError("'extends' cannot appear more than once in the same template")
     }
 
-    let blockNodes = parsedNodes.filter { node in node is BlockNode }
+    let blockNodes = parsedNodes.flatMap { $0 as? BlockNode }
 
-    let nodes = blockNodes.reduce([String:BlockNode]()) { (accumulator, node:NodeType) -> [String:BlockNode] in
-      let node = (node as! BlockNode)
+    let nodes = blockNodes.reduce([String: BlockNode]()) { (accumulator, node) -> [String: BlockNode] in
       var dict = accumulator
       dict[node.name] = node
       return dict
@@ -59,8 +58,8 @@ class ExtendsNode : NodeType {
     self.blocks = blocks
   }
 
-  func render(context: Context) throws -> String {
-    guard let loader = context["loader"] as? TemplateLoader else {
+  func render(_ context: Context) throws -> String {
+    guard let loader = context["loader"] as? Loader else {
       throw TemplateSyntaxError("Template loader not in context")
     }
 
@@ -68,13 +67,24 @@ class ExtendsNode : NodeType {
       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)")
+    guard let template = try loader.loadTemplate(name: templateName) else {
+      throw TemplateSyntaxError("'\(templateName)' template not found")
     }
 
-    let blockContext = BlockContext(blocks: blocks)
-    return try context.push([BlockContext.contextKey: blockContext]) {
+    let blockContext: BlockContext
+    if let context = context[BlockContext.contextKey] as? BlockContext {
+      blockContext = context
+
+      for (key, value) in blocks {
+        if !blockContext.blocks.keys.contains(key) {
+          blockContext.blocks[key] = value
+        }
+      }
+    } else {
+      blockContext = BlockContext(blocks: blocks)
+    }
+
+    return try context.push(dictionary: [BlockContext.contextKey: blockContext]) {
       return try template.render(context)
     }
   }
@@ -85,16 +95,16 @@ class BlockNode : NodeType {
   let name: String
   let nodes: [NodeType]
 
-  class func parse(parser: TokenParser, token: Token) throws -> 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")
+      throw TemplateSyntaxError("'block' tag takes one argument, the block name")
     }
 
     let blockName = bits[1]
     let nodes = try parser.parse(until(["endblock"]))
-    parser.nextToken()
+    _ = parser.nextToken()
     return BlockNode(name:blockName, nodes:nodes)
   }
 
@@ -103,8 +113,8 @@ class BlockNode : NodeType {
     self.nodes = nodes
   }
 
-  func render(context: Context) throws -> String {
-    if let blockContext = context[BlockContext.contextKey] as? BlockContext, node = blockContext.pop(name) {
+  func render(_ context: Context) throws -> String {
+    if let blockContext = context[BlockContext.contextKey] as? BlockContext, let node = blockContext.pop(name) {
       return try node.render(context)
     }
 

Sources/Lexer.swift

@@ -1,28 +1,30 @@
-public struct Lexer {
-  public let templateString: String
+struct Lexer {
+  let templateString: String
 
-  public init(templateString: String) {
+  init(templateString: String) {
     self.templateString = templateString
   }
 
   func createToken(string:String) -> Token {
     func strip() -> String {
-      return string[string.startIndex.successor().successor()..<string.endIndex.predecessor().predecessor()].trim(" ")
+      let start = string.index(string.startIndex, offsetBy: 2)
+      let end = string.index(string.endIndex, offsetBy: -2)
+      return string[start..<end].trim(character: " ")
     }
 
     if string.hasPrefix("{{") {
-      return Token.Variable(value: strip())
+      return .variable(value: strip())
     } else if string.hasPrefix("{%") {
-      return Token.Block(value: strip())
+      return .block(value: strip())
     } else if string.hasPrefix("{#") {
-      return Token.Comment(value: strip())
+      return .comment(value: strip())
     }
 
-    return Token.Text(value: string)
+    return .text(value: string)
   }
 
   /// Returns an array of tokens from a given template string.
-  public func tokenize() -> [Token] {
+  func tokenize() -> [Token] {
     var tokens: [Token] = []
 
     let scanner = Scanner(templateString)
@@ -36,14 +38,14 @@ public struct Lexer {
     while !scanner.isEmpty {
       if let text = scanner.scan(until: ["{{", "{%", "{#"]) {
         if !text.1.isEmpty {
-          tokens.append(createToken(text.1))
+          tokens.append(createToken(string: text.1))
         }
 
         let end = map[text.0]!
         let result = scanner.scan(until: end, returnUntil: true)
-        tokens.append(createToken(result))
+        tokens.append(createToken(string: result))
       } else {
-        tokens.append(createToken(scanner.content))
+        tokens.append(createToken(string: scanner.content))
         scanner.content = ""
       }
     }
@@ -64,49 +66,50 @@ class Scanner {
     return content.isEmpty
   }
 
-  func scan(until until: String, returnUntil: Bool = false) -> String {
+  func scan(until: String, returnUntil: Bool = false) -> String {
     if until.isEmpty {
       return ""
     }
 
     var index = content.startIndex
     while index != content.endIndex {
-      let substring = content[index..<content.endIndex]
+      let substring = content.substring(from: index)
+
       if substring.hasPrefix(until) {
-        let result = content[content.startIndex..<index]
+        let result = content.substring(to: index)
         content = substring
 
         if returnUntil {
-          content = content[until.endIndex..<content.endIndex]
+          content = content.substring(from: until.endIndex)
           return result + until
         }
 
         return result
       }
 
-      index = index.successor()
+      index = content.index(after: index)
     }
 
     return ""
   }
 
-  func scan(until until: [String]) -> (String, String)? {
+  func scan(until: [String]) -> (String, String)? {
     if until.isEmpty {
       return nil
     }
 
     var index = content.startIndex
     while index != content.endIndex {
-      let substring = content[index..<content.endIndex]
+      let substring = content.substring(from: index)
       for string in until {
         if substring.hasPrefix(string) {
-          let result = content[content.startIndex..<index]
+          let result = content.substring(to: index)
           content = substring
           return (string, result)
         }
       }
 
-      index = index.successor()
+      index = content.index(after: index)
     }
 
     return nil
@@ -117,31 +120,33 @@ class Scanner {
 extension String {
   func findFirstNot(character: Character) -> String.Index? {
     var index = startIndex
+
     while index != endIndex {
       if character != self[index] {
         return index
       }
-      index = index.successor()
+      index = self.index(after: index)
     }
 
     return nil
   }
 
   func findLastNot(character: Character) -> String.Index? {
-    var index = endIndex.predecessor()
+    var index = self.index(before: endIndex)
+
     while index != startIndex {
       if character != self[index] {
-        return index.successor()
+        return self.index(after: index)
       }
-      index = index.predecessor()
+      index = self.index(before: index)
     }
 
     return nil
   }
 
   func trim(character: Character) -> String {
-    let first = findFirstNot(character) ?? startIndex
-    let last = findLastNot(character) ?? endIndex
+    let first = findFirstNot(character: character) ?? startIndex
+    let last = findLastNot(character: character) ?? endIndex
     return self[first..<last]
   }
 }

Sources/Namespace.swift

@@ -1,3 +1,26 @@
+protocol FilterType {
+  func invoke(value: Any?, arguments: [Any?]) throws -> Any?
+}
+
+enum Filter: FilterType {
+  case simple(((Any?) throws -> Any?))
+  case arguments(((Any?, [Any?]) throws -> Any?))
+
+  func invoke(value: Any?, arguments: [Any?]) throws -> Any? {
+    switch self {
+    case let .simple(filter):
+      if !arguments.isEmpty {
+        throw TemplateSyntaxError("cannot invoke filter with an argument")
+      }
+
+      return try filter(value)
+    case let .arguments(filter):
+      return try filter(value, arguments)
+    }
+  }
+}
+
+
 public class Namespace {
   public typealias TagParser = (TokenParser, Token) throws -> NodeType
 
@@ -9,7 +32,7 @@ public class Namespace {
     registerDefaultFilters()
   }
 
-  private func registerDefaultTags() {
+  fileprivate func registerDefaultTags() {
     registerTag("for", parser: ForNode.parse)
     registerTag("if", parser: IfNode.parse)
     registerTag("ifnot", parser: IfNode.parse_ifnot)
@@ -21,26 +44,33 @@ public class Namespace {
     registerTag("block", parser: BlockNode.parse)
   }
 
-  private func registerDefaultFilters() {
+  fileprivate func registerDefaultFilters() {
+    registerFilter("default", filter: defaultFilter)
     registerFilter("capitalize", filter: capitalise)
     registerFilter("uppercase", filter: uppercase)
     registerFilter("lowercase", filter: lowercase)
+    registerFilter("join", filter: joinFilter)
   }
 
   /// Registers a new template tag
-  public func registerTag(name: String, parser: TagParser) {
+  public func registerTag(_ name: String, parser: @escaping TagParser) {
     tags[name] = parser
   }
 
   /// Registers a simple template tag with a name and a handler
-  public func registerSimpleTag(name: String, handler: Context throws -> String) {
+  public func registerSimpleTag(_ name: String, handler: @escaping (Context) throws -> String) {
     registerTag(name, parser: { parser, token in
       return SimpleNode(handler: handler)
     })
   }
 
   /// Registers a template filter with the given name
-  public func registerFilter(name: String, filter: Filter) {
-    filters[name] = filter
+  public func registerFilter(_ name: String, filter: @escaping (Any?) throws -> Any?) {
+    filters[name] = .simple(filter)
+  }
+
+  /// Registers a template filter with the given name
+  public func registerFilter(_ name: String, filter: @escaping (Any?, [Any?]) throws -> Any?) {
+    filters[name] = .arguments(filter)
   }
 }

Sources/Node.swift

@@ -1,7 +1,7 @@
 import Foundation
 
 
-public struct TemplateSyntaxError : ErrorType, Equatable, CustomStringConvertible {
+public struct TemplateSyntaxError : Error, Equatable, CustomStringConvertible {
   public let description:String
 
   public init(_ description:String) {
@@ -17,23 +17,23 @@ public func ==(lhs:TemplateSyntaxError, rhs:TemplateSyntaxError) -> Bool {
 
 public protocol NodeType {
   /// Render the node in the given context
-  func render(context:Context) throws -> String
+  func render(_ context:Context) throws -> String
 }
 
 
 /// Render the collection of nodes in the given context
-public func renderNodes(nodes:[NodeType], _ context:Context) throws -> String {
-  return try nodes.map { try $0.render(context) }.joinWithSeparator("")
+public func renderNodes(_ nodes:[NodeType], _ context:Context) throws -> String {
+  return try nodes.map { try $0.render(context) }.joined(separator: "")
 }
 
 public class SimpleNode : NodeType {
-  let handler:Context throws -> String
+  public let handler:(Context) throws -> String
 
-  public init(handler:Context throws -> String) {
+  public init(handler: @escaping (Context) throws -> String) {
     self.handler = handler
   }
 
-  public func render(context: Context) throws -> String {
+  public func render(_ context: Context) throws -> String {
     return try handler(context)
   }
 }
@@ -46,14 +46,14 @@ public class TextNode : NodeType {
     self.text = text
   }
 
-  public func render(context:Context) throws -> String {
+  public func render(_ context:Context) throws -> String {
     return self.text
   }
 }
 
 
 public protocol Resolvable {
-  func resolve(context: Context) throws -> Any?
+  func resolve(_ context: Context) throws -> Any?
 }
 
 
@@ -68,7 +68,7 @@ public class VariableNode : NodeType {
     self.variable = Variable(variable)
   }
 
-  public func render(context: Context) throws -> String {
+  public func render(_ context: Context) throws -> String {
     let result = try variable.resolve(context)
 
     if let result = result as? String {

Sources/NowTag.swift

@@ -2,10 +2,10 @@
 import Foundation
 
 
-public class NowNode : NodeType {
-  public let format:Variable
+class NowNode : NodeType {
+  let format:Variable
 
-  public class func parse(parser:TokenParser, token:Token) throws -> NodeType {
+  class func parse(_ parser:TokenParser, token:Token) throws -> NodeType {
     var format:Variable?
 
     let components = token.components()
@@ -19,25 +19,25 @@ public class NowNode : NodeType {
     return NowNode(format:format)
   }
 
-  public init(format:Variable?) {
+  init(format:Variable?) {
     self.format = format ?? Variable("\"yyyy-MM-dd 'at' HH:mm\"")
   }
 
-  public func render(context: Context) throws -> String {
-    let date = NSDate()
+  func render(_ context: Context) throws -> String {
+    let date = Date()
     let format = try self.format.resolve(context)
-    var formatter:NSDateFormatter?
+    var formatter:DateFormatter?
 
-    if let format = format as? NSDateFormatter {
+    if let format = format as? DateFormatter {
       formatter = format
     } else if let format = format as? String {
-      formatter = NSDateFormatter()
+      formatter = DateFormatter()
       formatter!.dateFormat = format
     } else {
       return ""
     }
 
-    return formatter!.stringFromDate(date)
+    return formatter!.string(from: date)
   }
 }
 #endif

Sources/Parser.swift

@@ -1,4 +1,4 @@
-public func until(tags: [String]) -> ((TokenParser, Token) -> Bool) {
+public func until(_ tags: [String]) -> ((TokenParser, Token) -> Bool) {
   return { parser, token in
     if let name = token.components().first {
       for tag in tags {
@@ -12,14 +12,13 @@ public func until(tags: [String]) -> ((TokenParser, Token) -> Bool) {
   }
 }
 
-public typealias Filter = Any? throws -> Any?
 
 /// A class for parsing an array of tokens and converts them into a collection of Node's
 public class TokenParser {
   public typealias TagParser = (TokenParser, Token) throws -> NodeType
 
-  private var tokens: [Token]
-  private let namespace: Namespace
+  fileprivate var tokens: [Token]
+  fileprivate let namespace: Namespace
 
   public init(tokens: [Token], namespace: Namespace) {
     self.tokens = tokens
@@ -31,21 +30,21 @@ public class TokenParser {
     return try parse(nil)
   }
 
-  public func parse(parse_until:((parser:TokenParser, token:Token) -> (Bool))?) throws -> [NodeType] {
+  public func parse(_ parse_until:((_ parser:TokenParser, _ token:Token) -> (Bool))?) throws -> [NodeType] {
     var nodes = [NodeType]()
 
     while tokens.count > 0 {
       let token = nextToken()!
 
       switch token {
-      case .Text(let text):
+      case .text(let text):
         nodes.append(TextNode(text: text))
-      case .Variable:
+      case .variable:
         nodes.append(VariableNode(variable: try compileFilter(token.contents)))
-      case .Block:
+      case .block:
         let tag = token.components().first
 
-        if let parse_until = parse_until where parse_until(parser: self, token: token) {
+        if let parse_until = parse_until , parse_until(self, token) {
           prependToken(token)
           return nodes
         }
@@ -57,7 +56,7 @@ public class TokenParser {
             throw TemplateSyntaxError("Unknown template tag '\(tag)'")
           }
         }
-      case .Comment:
+      case .comment:
         continue
       }
     }
@@ -67,17 +66,17 @@ public class TokenParser {
 
   public func nextToken() -> Token? {
     if tokens.count > 0 {
-      return tokens.removeAtIndex(0)
+      return tokens.remove(at: 0)
     }
 
     return nil
   }
 
-  public func prependToken(token:Token) {
-    tokens.insert(token, atIndex: 0)
+  public func prependToken(_ token:Token) {
+    tokens.insert(token, at: 0)
   }
 
-  public func findFilter(name: String) throws -> Filter {
+  func findFilter(_ name: String) throws -> FilterType {
     if let filter = namespace.filters[name] {
       return filter
     }
@@ -85,7 +84,7 @@ public class TokenParser {
     throw TemplateSyntaxError("Invalid filter '\(name)'")
   }
 
-  func compileFilter(token: String) throws -> Resolvable {
+  public func compileFilter(_ token: String) throws -> Resolvable {
     return try FilterExpression(token: token, parser: self)
   }
 }

Sources/Template.swift

@@ -6,13 +6,19 @@ let NSFileNoSuchFileError = 4
 #endif
 
 /// A class representing a template
-public class Template {
+public class Template: ExpressibleByStringLiteral {
   let tokens: [Token]
 
+  /// Create a template with a template string
+  public init(templateString: String) {
+    let lexer = Lexer(templateString: templateString)
+    tokens = lexer.tokenize()
+  }
+
   /// Create a template with the given name inside the given bundle
-  public convenience init(named:String, inBundle bundle:NSBundle? = nil) throws {
-    let useBundle = bundle ??  NSBundle.mainBundle()
-    guard let url = useBundle.URLForResource(named, withExtension: nil) else {
+  public convenience init(named:String, inBundle bundle:Bundle? = nil) throws {
+    let useBundle = bundle ??  Bundle.main
+    guard let url = useBundle.url(forResource: named, withExtension: nil) else {
       throw NSError(domain: NSCocoaErrorDomain, code: NSFileNoSuchFileError, userInfo: nil)
     }
 
@@ -20,23 +26,32 @@ public class Template {
   }
 
   /// Create a template with a file found at the given URL
-  public convenience init(URL:NSURL) throws {
-    try self.init(path: Path(URL.path!))
+  public convenience init(URL:Foundation.URL) throws {
+    try self.init(path: Path(URL.path))
   }
 
   /// Create a template with a file found at the given path
-  public convenience init(path:Path) throws {
+  public convenience init(path: Path) throws {
     self.init(templateString: try path.read())
   }
 
-  /// Create a template with a template string
-  public init(templateString:String) {
-    let lexer = Lexer(templateString: templateString)
-    tokens = lexer.tokenize()
+  // Create a template with a template string literal
+  public convenience required init(stringLiteral value: String) {
+    self.init(templateString: value)
+  }
+
+  // Create a template with a template string literal
+  public convenience required init(extendedGraphemeClusterLiteral value: StringLiteralType) {
+    self.init(stringLiteral: value)
+  }
+
+  // Create a template with a template string literal
+  public convenience required init(unicodeScalarLiteral value: StringLiteralType) {
+    self.init(stringLiteral: value)
   }
 
   /// Render the given template
-  public func render(context: Context? = nil) throws -> String {
+  public func render(_ context: Context? = nil) throws -> String {
     let context = context ?? Context()
     let parser = TokenParser(tokens: tokens, namespace: context.namespace)
     let nodes = try parser.parse()

Sources/TemplateLoader.swift

@@ -2,33 +2,60 @@ import Foundation
 import PathKit
 
 
+public protocol Loader {
+  func loadTemplate(name: String) throws -> Template?
+  func loadTemplate(names: [String]) throws -> Template?
+}
+
+
+extension Loader {
+  func loadTemplate(names: [String]) throws -> Template? {
+    for name in names {
+      let template = try loadTemplate(name: name)
+
+      if template != nil {
+        return template
+      }
+    }
+
+    return nil
+  }
+}
+
+
 // A class for loading a template from disk
-public class TemplateLoader {
+public class FileSystemLoader: Loader {
   public let paths: [Path]
 
   public init(paths: [Path]) {
     self.paths = paths
   }
 
-  public init(bundle: [NSBundle]) {
+  public init(bundle: [Bundle]) {
     self.paths = bundle.map {
       return Path($0.bundlePath)
     }
   }
 
-  public func loadTemplate(templateName: String) -> Template? {
-    return loadTemplate([templateName])
+  public func loadTemplate(name: String) throws -> Template? {
+    for path in paths {
+      let templatePath = path + Path(name)
+
+      if templatePath.exists {
+        return try Template(path: templatePath)
+      }
     }
 
-  public func loadTemplate(templateNames: [String]) -> Template? {
+    return nil
+  }
+
+  public func loadTemplate(names: [String]) throws -> Template? {
     for path in paths {
-      for templateName in templateNames {
+      for templateName in names {
         let templatePath = path + Path(templateName)
 
         if templatePath.exists {
-          if let template = try? Template(path: templatePath) {
-            return template
-          }
+          return try Template(path: templatePath)
         }
       }
     }

Sources/Tokenizer.swift

@@ -1,16 +1,17 @@
 import Foundation
 
 
-/// Split a string by spaces leaving quoted phrases together
-func smartSplit(value: String) -> [String] {
+extension String {
+  /// Split a string by a separator leaving quoted phrases together
+  func smartSplit(separator: Character = " ") -> [String] {
     var word = ""
-  var separator: Character = " "
     var components: [String] = []
+    var separate: Character = separator
 
-  for character in value.characters {
-    if character == separator {
-      if separator != " " {
-        word.append(separator)
+    for character in self.characters {
+      if character == separate {
+        if separate != separator {
+          word.append(separate)
         }
 
         if !word.isEmpty {
@@ -18,10 +19,10 @@ func smartSplit(value: String) -> [String] {
           word = ""
         }
 
-      separator = " "
+        separate = separator
       } else {
-      if separator == " " && (character == "'" || character == "\"") {
-        separator = character
+        if separate == separator && (character == "'" || character == "\"") {
+          separate = character
         }
         word.append(character)
       }
@@ -32,45 +33,46 @@ func smartSplit(value: String) -> [String] {
     }
 
     return components
+  }
 }
 
 
 public enum Token : Equatable {
   /// A token representing a piece of text.
-  case Text(value: String)
+  case text(value: String)
 
   /// A token representing a variable.
-  case Variable(value: String)
+  case variable(value: String)
 
   /// A token representing a comment.
-  case Comment(value: String)
+  case comment(value: String)
 
   /// A token representing a template block.
-  case Block(value: String)
+  case block(value: String)
 
   /// Returns the underlying value as an array seperated by spaces
   public func components() -> [String] {
     switch self {
-    case .Block(let value):
-      return smartSplit(value)
-    case .Variable(let value):
-      return smartSplit(value)
-    case .Text(let value):
-      return smartSplit(value)
-    case .Comment(let value):
-      return smartSplit(value)
+    case .block(let value):
+      return value.smartSplit()
+    case .variable(let value):
+      return value.smartSplit()
+    case .text(let value):
+      return value.smartSplit()
+    case .comment(let value):
+      return value.smartSplit()
     }
   }
 
   public var contents: String {
     switch self {
-    case .Block(let value):
+    case .block(let value):
       return value
-    case .Variable(let value):
+    case .variable(let value):
       return value
-    case .Text(let value):
+    case .text(let value):
       return value
-    case .Comment(let value):
+    case .comment(let value):
       return value
     }
   }
@@ -79,13 +81,13 @@ public enum Token : Equatable {
 
 public func == (lhs: Token, rhs: Token) -> Bool {
   switch (lhs, rhs) {
-  case (.Text(let lhsValue), .Text(let rhsValue)):
+  case (.text(let lhsValue), .text(let rhsValue)):
     return lhsValue == rhsValue
-  case (.Variable(let lhsValue), .Variable(let rhsValue)):
+  case (.variable(let lhsValue), .variable(let rhsValue)):
     return lhsValue == rhsValue
-  case (.Block(let lhsValue), .Block(let rhsValue)):
+  case (.block(let lhsValue), .block(let rhsValue)):
     return lhsValue == rhsValue
-  case (.Comment(let lhsValue), .Comment(let rhsValue)):
+  case (.comment(let lhsValue), .comment(let rhsValue)):
     return lhsValue == rhsValue
   default:
     return false

Sources/Variable.swift

@@ -2,11 +2,11 @@ import Foundation
 
 
 class FilterExpression : Resolvable {
-  let filters: [Filter]
+  let filters: [(FilterType, [Variable])]
   let variable: Variable
 
   init(token: String, parser: TokenParser) throws {
-    let bits = token.characters.split("|").map({ String($0).trim(" ") })
+    let bits = token.characters.split(separator: "|").map({ String($0).trim(character: " ") })
     if bits.isEmpty {
       filters = []
       variable = Variable("")
@@ -14,21 +14,26 @@ class FilterExpression : Resolvable {
     }
 
     variable = Variable(bits[0])
-    let filterBits = bits[1 ..< bits.endIndex]
+    let filterBits = bits[bits.indices.suffix(from: 1)]
 
     do {
-      filters = try filterBits.map { try parser.findFilter($0) }
+      filters = try filterBits.map {
+        let (name, arguments) = parseFilterComponents(token: $0)
+        let filter = try parser.findFilter(name)
+        return (filter, arguments)
+      }
     } catch {
       filters = []
       throw error
     }
   }
 
-  func resolve(context: Context) throws -> Any? {
+  func resolve(_ context: Context) throws -> Any? {
     let result = try variable.resolve(context)
 
     return try filters.reduce(result) { x, y in
-      return try y(x)
+      let arguments = try y.1.map { try $0.resolve(context) }
+      return try y.0.invoke(value: x, arguments: arguments)
     }
   }
 }
@@ -42,17 +47,17 @@ public struct Variable : Equatable, Resolvable {
     self.variable = variable
   }
 
-  private func lookup() -> [String] {
-    return variable.characters.split(".").map(String.init)
+  fileprivate func lookup() -> [String] {
+    return variable.characters.split(separator: ".").map(String.init)
   }
 
   /// Resolve the variable in the given context
-  public func resolve(context: Context) throws -> Any? {
+  public func resolve(_ context: Context) throws -> Any? {
     var current: Any? = context
 
     if (variable.hasPrefix("'") && variable.hasSuffix("'")) || (variable.hasPrefix("\"") && variable.hasSuffix("\"")) {
       // String literal
-      return variable[variable.startIndex.successor() ..< variable.endIndex.predecessor()]
+      return variable[variable.characters.index(after: variable.startIndex) ..< variable.characters.index(before: variable.endIndex)]
     }
 
     for bit in lookup() {
@@ -64,7 +69,11 @@ public struct Variable : Equatable, Resolvable {
         current = dictionary[bit]
       } else if let array = current as? [Any] {
         if let index = Int(bit) {
+          if index >= 0 && index < array.count {
             current = array[index]
+          } else {
+            current = nil
+          }
         } else if bit == "first" {
           current = array.first
         } else if bit == "last" {
@@ -76,8 +85,15 @@ public struct Variable : Equatable, Resolvable {
 #if os(Linux)
         return nil
 #else
-        current = object.valueForKey(bit)
+        current = object.value(forKey: bit)
 #endif
+      } else if let value = current {
+        let mirror = Mirror(reflecting: value)
+        current = mirror.descendant(bit)
+
+        if current == nil {
+          return nil
+        }
       } else {
         return nil
       }
@@ -92,7 +108,7 @@ public func ==(lhs: Variable, rhs: Variable) -> Bool {
 }
 
 
-func normalize(current: Any?) -> Any? {
+func normalize(_ current: Any?) -> Any? {
   if let current = current as? Normalizable {
     return current.normalize()
   }
@@ -131,3 +147,13 @@ extension Dictionary : Normalizable {
     return dictionary
   }
 }
+
+func parseFilterComponents(token: String) -> (String, [Variable]) {
+  var components = token.smartSplit(separator: ":")
+  let name = components.removeFirst()
+  let variables = components
+    .joined(separator: ":")
+    .smartSplit(separator: ",")
+    .map { Variable($0) }
+  return (name, variables)
+}

Stencil.podspec.json

@@ -1,8 +1,8 @@
 {
   "name": "Stencil",
-  "version": "0.6.0-beta.1",
+  "version": "0.7.0",
   "summary": "Stencil is a simple and powerful template language for Swift.",
-  "homepage": "https://github.com/kylef/Stencil",
+  "homepage": "https://stencil.fuller.li",
   "license": {
     "type": "BSD",
     "file": "LICENSE"
@@ -10,20 +10,21 @@
   "authors": {
     "Kyle Fuller": "kyle@fuller.li"
   },
-  "social_media_url": "http://twitter.com/kylefuller",
+  "social_media_url": "https://twitter.com/kylefuller",
   "source": {
     "git": "https://github.com/kylef/Stencil.git",
-    "tag": "0.6.0-beta.1"
+    "tag": "0.6.0"
   },
   "source_files": [
     "Sources/*.swift"
   ],
   "platforms": {
     "ios": "8.0",
-    "osx": "10.9"
+    "osx": "10.9",
+    "tvos": "9.0"
   },
   "requires_arc": true,
   "dependencies": {
-    "PathKit": [ "~> 0.6.0" ]
+    "PathKit": [ "~> 0.7.0" ]
   }
 }

Tests/LinuxMain.swift

@@ -0,0 +1,3 @@
+import StencilTests
+
+stencilTests()

Tests/Nodes/IfNodeSpec.swift

@@ -1,116 +0,0 @@
-import Spectre
-import Stencil
-
-
-func testIfNode() {
-  describe("IfNode") {
-    $0.describe("parsing") {
-      $0.it("can parse an if block") {
-        let tokens = [
-          Token.Block(value: "if value"),
-          Token.Text(value: "true"),
-          Token.Block(value: "else"),
-          Token.Text(value: "false"),
-          Token.Block(value: "endif")
-        ]
-
-        let parser = TokenParser(tokens: tokens, namespace: Namespace())
-        let nodes = try parser.parse()
-        let node = nodes.first as? IfNode
-        let trueNode = node?.trueNodes.first as? TextNode
-        let falseNode = node?.falseNodes.first as? TextNode
-
-        try expect(nodes.count) == 1
-        try expect(node?.variable.variable) == "value"
-        try expect(node?.trueNodes.count) == 1
-        try expect(trueNode?.text) == "true"
-        try expect(node?.falseNodes.count) == 1
-        try expect(falseNode?.text) == "false"
-      }
-
-      $0.it("can parse an ifnot block") {
-        let tokens = [
-          Token.Block(value: "ifnot value"),
-          Token.Text(value: "false"),
-          Token.Block(value: "else"),
-          Token.Text(value: "true"),
-          Token.Block(value: "endif")
-        ]
-
-        let parser = TokenParser(tokens: tokens, namespace: Namespace())
-        let nodes = try parser.parse()
-        let node = nodes.first as? IfNode
-        let trueNode = node?.trueNodes.first as? TextNode
-        let falseNode = node?.falseNodes.first as? TextNode
-
-        try expect(nodes.count) == 1
-        try expect(node?.variable.variable) == "value"
-        try expect(node?.trueNodes.count) == 1
-        try expect(trueNode?.text) == "true"
-        try expect(node?.falseNodes.count) == 1
-        try expect(falseNode?.text) == "false"
-      }
-
-      $0.it("throws an error when parsing an if block without an endif") {
-        let tokens = [
-          Token.Block(value: "if value"),
-        ]
-
-        let parser = TokenParser(tokens: tokens, namespace: Namespace())
-        let error = TemplateSyntaxError("`endif` was not found.")
-        try expect(try parser.parse()).toThrow(error)
-      }
-
-      $0.it("throws an error when parsing an ifnot without an endif") {
-        let tokens = [
-          Token.Block(value: "ifnot value"),
-        ]
-
-        let parser = TokenParser(tokens: tokens, namespace: Namespace())
-        let error = TemplateSyntaxError("`endif` was not found.")
-        try expect(try parser.parse()).toThrow(error)
-      }
-    }
-
-    $0.describe("rendering") {
-      let context = Context(dictionary: ["items": true])
-
-      $0.it("renders the truth when expression evaluates to true") {
-        let node = IfNode(variable: "items", trueNodes: [TextNode(text: "true")], falseNodes: [TextNode(text: "false")])
-        try expect(try node.render(context)) == "true"
-      }
-
-      $0.it("renders the false when expression evaluates to false") {
-        let node = IfNode(variable: "unknown", trueNodes: [TextNode(text: "true")], falseNodes: [TextNode(text: "false")])
-        try expect(try node.render(context)) == "false"
-      }
-
-      $0.it("renders the truth when array expression is not empty") {
-        let items: [[String: Any]] = [["key":"key1","value":42],["key":"key2","value":1337]]
-        let arrayContext = Context(dictionary: ["items": [items]])
-        let node = IfNode(variable: "items", trueNodes: [TextNode(text: "true")], falseNodes: [TextNode(text: "false")])
-        try expect(try node.render(arrayContext)) == "true"
-      }
-
-      $0.it("renders the false when array expression is empty") {
-        let emptyItems = [[String: Any]]()
-        let arrayContext = Context(dictionary: ["items": emptyItems])
-        let node = IfNode(variable: "items", trueNodes: [TextNode(text: "true")], falseNodes: [TextNode(text: "false")])
-        try expect(try node.render(arrayContext)) == "false"
-      }
-
-      $0.it("renders the false when dictionary expression is empty") {
-        let emptyItems = [String:Any]()
-        let arrayContext = Context(dictionary: ["items": emptyItems])
-        let node = IfNode(variable: "items", trueNodes: [TextNode(text: "true")], falseNodes: [TextNode(text: "false")])
-        try expect(try node.render(arrayContext)) == "false"
-      }
-
-      $0.it("renders the false when Array<Any> variable is empty") {
-        let arrayContext = Context(dictionary: ["items": ([] as [Any])])
-        let node = IfNode(variable: "items", trueNodes: [TextNode(text: "true")], falseNodes: [TextNode(text: "false")])
-        try expect(try node.render(arrayContext)) == "false"
-      }
-    }
-  }
-}

Tests/StencilTests/ContextSpec.swift

@@ -47,10 +47,19 @@ func testContext() {
       try expect(context["name"] as? String) == "Kyle"
     }
 
+    $0.it("allows you to remove a parent's value in a level") {
+      try context.push {
+        context["name"] = nil
+        try expect(context["name"]).to.beNil()
+      }
+
+      try expect(context["name"] as? String) == "Kyle"
+    }
+
     $0.it("allows you to push a dictionary and run a closure then restoring previous state") {
       var didRun = false
 
-      try context.push(["name": "Katie"]) {
+      try context.push(dictionary: ["name": "Katie"]) {
         didRun = true
         try expect(context["name"] as? String) == "Katie"
       }
@@ -58,5 +67,15 @@ func testContext() {
       try expect(didRun).to.beTrue()
       try expect(context["name"] as? String) == "Kyle"
     }
+
+    $0.it("allows you to flatten the context contents") {
+      try context.push(dictionary: ["test": "abc"]) {
+        let flattened = context.flatten()
+
+        try expect(flattened.count) == 2
+        try expect(flattened["name"] as? String) == "Kyle"
+        try expect(flattened["test"] as? String) == "abc"
+      }
+    }
   }
 }

Tests/StencilTests/ExpressionSpec.swift

@@ -0,0 +1,282 @@
+import Spectre
+@testable import Stencil
+
+
+func testExpressions() {
+  describe("Expression") {
+    $0.describe("VariableExpression") {
+      let expression = VariableExpression(variable: Variable("value"))
+
+      $0.it("evaluates to true when value is not nil") {
+        let context = Context(dictionary: ["value": "known"])
+        try expect(try expression.evaluate(context: context)).to.beTrue()
+      }
+
+      $0.it("evaluates to false when value is unset") {
+        let context = Context()
+        try expect(try expression.evaluate(context: context)).to.beFalse()
+      }
+
+      $0.it("evaluates to true when array variable is not empty") {
+        let items: [[String: Any]] = [["key":"key1","value":42],["key":"key2","value":1337]]
+        let context = Context(dictionary: ["value": [items]])
+        try expect(try expression.evaluate(context: context)).to.beTrue()
+      }
+
+      $0.it("evaluates to false when array value is empty") {
+        let emptyItems = [[String: Any]]()
+        let context = Context(dictionary: ["value": emptyItems])
+        try expect(try expression.evaluate(context: context)).to.beFalse()
+      }
+
+      $0.it("evaluates to false when dictionary value is empty") {
+        let emptyItems = [String:Any]()
+        let context = Context(dictionary: ["value": emptyItems])
+        try expect(try expression.evaluate(context: context)).to.beFalse()
+      }
+
+      $0.it("evaluates to false when Array<Any> value is empty") {
+        let context = Context(dictionary: ["value": ([] as [Any])])
+        try expect(try expression.evaluate(context: context)).to.beFalse()
+      }
+
+      $0.it("evaluates to true when integer value is above 0") {
+        let context = Context(dictionary: ["value": 1])
+        try expect(try expression.evaluate(context: context)).to.beTrue()
+      }
+
+      $0.it("evaluates to true with string") {
+        let context = Context(dictionary: ["value": "test"])
+        try expect(try expression.evaluate(context: context)).to.beTrue()
+      }
+
+      $0.it("evaluates to false when empty string") {
+        let context = Context(dictionary: ["value": ""])
+        try expect(try expression.evaluate(context: context)).to.beFalse()
+      }
+
+      $0.it("evaluates to false when integer value is below 0 or below") {
+        let context = Context(dictionary: ["value": 0])
+        try expect(try expression.evaluate(context: context)).to.beFalse()
+
+        let negativeContext = Context(dictionary: ["value": 0])
+        try expect(try expression.evaluate(context: negativeContext)).to.beFalse()
+      }
+
+      $0.it("evaluates to true when float value is above 0") {
+        let context = Context(dictionary: ["value": Float(0.5)])
+        try expect(try expression.evaluate(context: context)).to.beTrue()
+      }
+
+      $0.it("evaluates to false when float is 0 or below") {
+        let context = Context(dictionary: ["value": Float(0)])
+        try expect(try expression.evaluate(context: context)).to.beFalse()
+      }
+
+      $0.it("evaluates to true when double value is above 0") {
+        let context = Context(dictionary: ["value": Double(0.5)])
+        try expect(try expression.evaluate(context: context)).to.beTrue()
+      }
+
+      $0.it("evaluates to false when double is 0 or below") {
+        let context = Context(dictionary: ["value": Double(0)])
+        try expect(try expression.evaluate(context: context)).to.beFalse()
+      }
+
+      $0.it("evaluates to false when uint is 0") {
+        let context = Context(dictionary: ["value": UInt(0)])
+        try expect(try expression.evaluate(context: context)).to.beFalse()
+      }
+    }
+
+    $0.describe("NotExpression") {
+      $0.it("returns truthy for positive expressions") {
+        let expression = NotExpression(expression: StaticExpression(value: true))
+        try expect(expression.evaluate(context: Context())).to.beFalse()
+      }
+
+      $0.it("returns falsy for negative expressions") {
+        let expression = NotExpression(expression: StaticExpression(value: false))
+        try expect(expression.evaluate(context: Context())).to.beTrue()
+      }
+    }
+
+    $0.describe("expression parsing") {
+      $0.it("can parse a variable expression") {
+        let expression = try parseExpression(components: ["value"])
+        try expect(expression.evaluate(context: Context())).to.beFalse()
+        try expect(expression.evaluate(context: Context(dictionary: ["value": true]))).to.beTrue()
+      }
+
+      $0.it("can parse a not expression") {
+        let expression = try parseExpression(components: ["not", "value"])
+        try expect(expression.evaluate(context: Context())).to.beTrue()
+        try expect(expression.evaluate(context: Context(dictionary: ["value": true]))).to.beFalse()
+      }
+
+      $0.describe("and expression") {
+        let expression = try! parseExpression(components: ["lhs", "and", "rhs"])
+
+        $0.it("evaluates to false with lhs false") {
+          try expect(expression.evaluate(context: Context(dictionary: ["lhs": false, "rhs": true]))).to.beFalse()
+        }
+
+        $0.it("evaluates to false with rhs false") {
+          try expect(expression.evaluate(context: Context(dictionary: ["lhs": true, "rhs": false]))).to.beFalse()
+        }
+
+        $0.it("evaluates to false with lhs and rhs false") {
+          try expect(expression.evaluate(context: Context(dictionary: ["lhs": false, "rhs": false]))).to.beFalse()
+        }
+
+        $0.it("evaluates to true with lhs and rhs true") {
+          try expect(expression.evaluate(context: Context(dictionary: ["lhs": true, "rhs": true]))).to.beTrue()
+        }
+      }
+
+      $0.describe("or expression") {
+        let expression = try! parseExpression(components: ["lhs", "or", "rhs"])
+
+        $0.it("evaluates to true with lhs true") {
+          try expect(expression.evaluate(context: Context(dictionary: ["lhs": true, "rhs": false]))).to.beTrue()
+        }
+
+        $0.it("evaluates to true with rhs true") {
+          try expect(expression.evaluate(context: Context(dictionary: ["lhs": false, "rhs": true]))).to.beTrue()
+        }
+
+        $0.it("evaluates to true with lhs and rhs true") {
+          try expect(expression.evaluate(context: Context(dictionary: ["lhs": true, "rhs": true]))).to.beTrue()
+        }
+
+        $0.it("evaluates to false with lhs and rhs false") {
+          try expect(expression.evaluate(context: Context(dictionary: ["lhs": false, "rhs": false]))).to.beFalse()
+        }
+      }
+
+      $0.describe("equality expression") {
+        let expression = try! parseExpression(components: ["lhs", "==", "rhs"])
+
+        $0.it("evaluates to true with equal lhs/rhs") {
+          try expect(expression.evaluate(context: Context(dictionary: ["lhs": "a", "rhs": "a"]))).to.beTrue()
+        }
+
+        $0.it("evaluates to false with non equal lhs/rhs") {
+          try expect(expression.evaluate(context: Context(dictionary: ["lhs": "a", "rhs": "b"]))).to.beFalse()
+        }
+
+        $0.it("evaluates to true with nils") {
+          try expect(expression.evaluate(context: Context(dictionary: [:]))).to.beTrue()
+        }
+
+        $0.it("evaluates to true with numbers") {
+          try expect(expression.evaluate(context: Context(dictionary: ["lhs": 1, "rhs": 1.0]))).to.beTrue()
+        }
+
+        $0.it("evaluates to false with non equal numbers") {
+          try expect(expression.evaluate(context: Context(dictionary: ["lhs": 1, "rhs": 1.1]))).to.beFalse()
+        }
+
+        $0.it("evaluates to true with booleans") {
+          try expect(expression.evaluate(context: Context(dictionary: ["lhs": true, "rhs": true]))).to.beTrue()
+        }
+
+        $0.it("evaluates to false with falsy booleans") {
+          try expect(expression.evaluate(context: Context(dictionary: ["lhs": true, "rhs": false]))).to.beFalse()
+        }
+
+        $0.it("evaluates to false with different types") {
+          try expect(expression.evaluate(context: Context(dictionary: ["lhs": true, "rhs": 1]))).to.beFalse()
+        }
+      }
+
+      $0.describe("inequality expression") {
+        let expression = try! parseExpression(components: ["lhs", "!=", "rhs"])
+
+        $0.it("evaluates to true with inequal lhs/rhs") {
+          try expect(expression.evaluate(context: Context(dictionary: ["lhs": "a", "rhs": "b"]))).to.beTrue()
+        }
+
+        $0.it("evaluates to false with equal lhs/rhs") {
+          try expect(expression.evaluate(context: Context(dictionary: ["lhs": "b", "rhs": "b"]))).to.beFalse()
+        }
+      }
+
+      $0.describe("more than expression") {
+        let expression = try! parseExpression(components: ["lhs", ">", "rhs"])
+
+        $0.it("evaluates to true with lhs > rhs") {
+          try expect(expression.evaluate(context: Context(dictionary: ["lhs": 5.0, "rhs": 4]))).to.beTrue()
+        }
+
+        $0.it("evaluates to false with lhs == rhs") {
+          try expect(expression.evaluate(context: Context(dictionary: ["lhs": 5.0, "rhs": 5.0]))).to.beFalse()
+        }
+      }
+
+      $0.describe("more than equal expression") {
+        let expression = try! parseExpression(components: ["lhs", ">=", "rhs"])
+
+        $0.it("evaluates to true with lhs == rhs") {
+          try expect(expression.evaluate(context: Context(dictionary: ["lhs": 5.0, "rhs": 5]))).to.beTrue()
+        }
+
+        $0.it("evaluates to false with lhs < rhs") {
+          try expect(expression.evaluate(context: Context(dictionary: ["lhs": 5.0, "rhs": 5.1]))).to.beFalse()
+        }
+      }
+
+      $0.describe("less than expression") {
+        let expression = try! parseExpression(components: ["lhs", "<", "rhs"])
+
+        $0.it("evaluates to true with lhs < rhs") {
+          try expect(expression.evaluate(context: Context(dictionary: ["lhs": 4, "rhs": 4.5]))).to.beTrue()
+        }
+
+        $0.it("evaluates to false with lhs == rhs") {
+          try expect(expression.evaluate(context: Context(dictionary: ["lhs": 5.0, "rhs": 5.0]))).to.beFalse()
+        }
+      }
+
+      $0.describe("less than equal expression") {
+        let expression = try! parseExpression(components: ["lhs", "<=", "rhs"])
+
+        $0.it("evaluates to true with lhs == rhs") {
+          try expect(expression.evaluate(context: Context(dictionary: ["lhs": 5.0, "rhs": 5]))).to.beTrue()
+        }
+
+        $0.it("evaluates to false with lhs > rhs") {
+          try expect(expression.evaluate(context: Context(dictionary: ["lhs": 5.1, "rhs": 5.0]))).to.beFalse()
+        }
+      }
+
+      $0.describe("multiple expression") {
+        let expression = try! parseExpression(components: ["one", "or", "two", "and", "not", "three"])
+
+        $0.it("evaluates to true with one") {
+          try expect(expression.evaluate(context: Context(dictionary: ["one": true]))).to.beTrue()
+        }
+
+        $0.it("evaluates to true with one and three") {
+          try expect(expression.evaluate(context: Context(dictionary: ["one": true, "three": true]))).to.beTrue()
+        }
+
+        $0.it("evaluates to true with two") {
+          try expect(expression.evaluate(context: Context(dictionary: ["two": true]))).to.beTrue()
+        }
+
+        $0.it("evaluates to false with two and three") {
+          try expect(expression.evaluate(context: Context(dictionary: ["two": true, "three": true]))).to.beFalse()
+        }
+
+        $0.it("evaluates to false with two and three") {
+          try expect(expression.evaluate(context: Context(dictionary: ["two": true, "three": true]))).to.beFalse()
+        }
+
+        $0.it("evaluates to false with nothing") {
+          try expect(expression.evaluate(context: Context())).to.beFalse()
+        }
+      }
+    }
+  }
+}

Tests/StencilTests/FilterSpec.swift

@@ -10,7 +10,7 @@ func testFilter() {
       let template = Template(templateString: "{{ name|repeat }}")
 
       let namespace = Namespace()
-      namespace.registerFilter("repeat") { value in
+      namespace.registerFilter("repeat") { (value: Any?) in
         if let value = value as? String {
           return "\(value) \(value)"
         }
@@ -22,10 +22,26 @@ func testFilter() {
       try expect(result) == "Kyle Kyle"
     }
 
+    $0.it("allows you to register a custom filter which accepts arguments") {
+      let template = Template(templateString: "{{ name|repeat:'value' }}")
+
+      let namespace = Namespace()
+      namespace.registerFilter("repeat") { value, arguments in
+        if !arguments.isEmpty {
+          return "\(value!) \(value!) with args \(arguments.first!!)"
+        }
+
+        return nil
+      }
+
+      let result = try template.render(Context(dictionary: context, namespace: namespace))
+      try expect(result) == "Kyle Kyle with args value"
+    }
+
     $0.it("allows you to register a custom which throws") {
       let template = Template(templateString: "{{ name|repeat }}")
       let namespace = Namespace()
-      namespace.registerFilter("repeat") { value in
+      namespace.registerFilter("repeat") { (value: Any?) in
         throw TemplateSyntaxError("No Repeat")
       }
 
@@ -37,6 +53,11 @@ func testFilter() {
       let result = try template.render(Context(dictionary: ["name": "kyle"]))
       try expect(result) == "KYLE"
     }
+
+    $0.it("throws when you pass arguments to simple filter") {
+      let template = Template(templateString: "{{ name|uppercase:5 }}")
+      try expect(try template.render(Context(dictionary: ["name": "kyle"]))).toThrow()
+    }
   }
 
 
@@ -67,4 +88,33 @@ func testFilter() {
       try expect(result) == "kyle"
     }
   }
+
+  describe("default filter") {
+    let template = Template(templateString: "Hello {{ name|default:\"World\" }}")
+
+    $0.it("shows the variable value") {
+      let result = try template.render(Context(dictionary: ["name": "Kyle"]))
+      try expect(result) == "Hello Kyle"
+    }
+
+    $0.it("shows the default value") {
+      let result = try template.render(Context(dictionary: [:]))
+      try expect(result) == "Hello World"
+    }
+
+    $0.it("supports multiple defaults") {
+      let template = Template(templateString: "Hello {{ name|default:a,b,c,\"World\" }}")
+      let result = try template.render(Context(dictionary: [:]))
+      try expect(result) == "Hello World"
+    }
+  }
+
+  describe("join filter") {
+    let template = Template(templateString: "{{ value|join:\", \" }}")
+
+    $0.it("transforms a string to be lowercase") {
+      let result = try template.render(Context(dictionary: ["value": ["One", "Two"]]))
+      try expect(result) == "One, Two"
+    }
+  }
 }

Tests/StencilTests/ForNodeSpec.swift

@@ -1,5 +1,5 @@
 import Spectre
-import Stencil
+@testable import Stencil
 import Foundation
 
 
@@ -12,14 +12,14 @@ func testForNode() {
 
     $0.it("renders the given nodes for each item") {
       let nodes: [NodeType] = [VariableNode(variable: "item")]
-      let node = ForNode(variable: "items", loopVariable: "item", nodes: nodes, emptyNodes: [])
+      let node = ForNode(resolvable: Variable("items"), loopVariable: "item", nodes: nodes, emptyNodes: [])
       try expect(try node.render(context)) == "123"
     }
 
     $0.it("renders the given empty nodes when no items found item") {
       let nodes: [NodeType] = [VariableNode(variable: "item")]
       let emptyNodes: [NodeType] = [TextNode(text: "empty")]
-      let node = ForNode(variable: "emptyItems", loopVariable: "item", nodes: nodes, emptyNodes: emptyNodes)
+      let node = ForNode(resolvable: Variable("emptyItems"), loopVariable: "item", nodes: nodes, emptyNodes: emptyNodes)
       try expect(try node.render(context)) == "empty"
     }
 
@@ -29,7 +29,7 @@ func testForNode() {
       ])
 
       let nodes: [NodeType] = [VariableNode(variable: "item")]
-      let node = ForNode(variable: "items", loopVariable: "item", nodes: nodes, emptyNodes: [])
+      let node = ForNode(resolvable: Variable("items"), loopVariable: "item", nodes: nodes, emptyNodes: [])
       try expect(try node.render(any_context)) == "123"
     }
 
@@ -40,27 +40,56 @@ func testForNode() {
       ])
 
       let nodes: [NodeType] = [VariableNode(variable: "item")]
-      let node = ForNode(variable: "items", loopVariable: "item", nodes: nodes, emptyNodes: [])
+      let node = ForNode(resolvable: Variable("items"), loopVariable: "item", nodes: nodes, emptyNodes: [])
       try expect(try node.render(nsarray_context)) == "123"
     }
 #endif
 
     $0.it("renders the given nodes while providing if the item is first in the context") {
       let nodes: [NodeType] = [VariableNode(variable: "item"), VariableNode(variable: "forloop.first")]
-      let node = ForNode(variable: "items", loopVariable: "item", nodes: nodes, emptyNodes: [])
+      let node = ForNode(resolvable: Variable("items"), loopVariable: "item", nodes: nodes, emptyNodes: [])
       try expect(try node.render(context)) == "1true2false3false"
     }
 
     $0.it("renders the given nodes while providing if the item is last in the context") {
       let nodes: [NodeType] = [VariableNode(variable: "item"), VariableNode(variable: "forloop.last")]
-      let node = ForNode(variable: "items", loopVariable: "item", nodes: nodes, emptyNodes: [])
+      let node = ForNode(resolvable: Variable("items"), loopVariable: "item", nodes: nodes, emptyNodes: [])
       try expect(try node.render(context)) == "1false2false3true"
     }
 
     $0.it("renders the given nodes while providing item counter") {
       let nodes: [NodeType] = [VariableNode(variable: "item"), VariableNode(variable: "forloop.counter")]
-      let node = ForNode(variable: "items", loopVariable: "item", nodes: nodes, emptyNodes: [])
+      let node = ForNode(resolvable: Variable("items"), loopVariable: "item", nodes: nodes, emptyNodes: [])
       try expect(try node.render(context)) == "112233"
     }
+
+    $0.it("can render a filter") {
+      let templateString = "{% for article in ars|default:articles %}" +
+        "- {{ article.title }} by {{ article.author }}.\n" +
+        "{% endfor %}\n"
+
+      let context = Context(dictionary: [
+        "articles": [
+          Article(title: "Migrating from OCUnit to XCTest", author: "Kyle Fuller"),
+          Article(title: "Memory Management with ARC", author: "Kyle Fuller"),
+        ]
+      ])
+
+      let template = Template(templateString: templateString)
+      let result = try template.render(context)
+
+      let fixture = "" +
+        "- Migrating from OCUnit to XCTest by Kyle Fuller.\n" +
+        "- Memory Management with ARC by Kyle Fuller.\n" +
+        "\n"
+
+      try expect(result) == fixture
+    }
   }
 }
+
+
+fileprivate struct Article {
+  let title: String
+  let author: String
+}

Tests/StencilTests/IfNodeSpec.swift

@@ -0,0 +1,85 @@
+import Spectre
+@testable import Stencil
+
+
+func testIfNode() {
+  describe("IfNode") {
+    $0.describe("parsing") {
+      $0.it("can parse an if block") {
+        let tokens: [Token] = [
+          .block(value: "if value"),
+          .text(value: "true"),
+          .block(value: "else"),
+          .text(value: "false"),
+          .block(value: "endif")
+        ]
+
+        let parser = TokenParser(tokens: tokens, namespace: Namespace())
+        let nodes = try parser.parse()
+        let node = nodes.first as? IfNode
+        let trueNode = node?.trueNodes.first as? TextNode
+        let falseNode = node?.falseNodes.first as? TextNode
+
+        try expect(nodes.count) == 1
+        try expect(node?.trueNodes.count) == 1
+        try expect(trueNode?.text) == "true"
+        try expect(node?.falseNodes.count) == 1
+        try expect(falseNode?.text) == "false"
+      }
+
+      $0.it("can parse an ifnot block") {
+        let tokens: [Token] = [
+          .block(value: "ifnot value"),
+          .text(value: "false"),
+          .block(value: "else"),
+          .text(value: "true"),
+          .block(value: "endif")
+        ]
+
+        let parser = TokenParser(tokens: tokens, namespace: Namespace())
+        let nodes = try parser.parse()
+        let node = nodes.first as? IfNode
+        let trueNode = node?.trueNodes.first as? TextNode
+        let falseNode = node?.falseNodes.first as? TextNode
+
+        try expect(nodes.count) == 1
+        try expect(node?.trueNodes.count) == 1
+        try expect(trueNode?.text) == "true"
+        try expect(node?.falseNodes.count) == 1
+        try expect(falseNode?.text) == "false"
+      }
+
+      $0.it("throws an error when parsing an if block without an endif") {
+        let tokens: [Token] = [
+          .block(value: "if value"),
+        ]
+
+        let parser = TokenParser(tokens: tokens, namespace: Namespace())
+        let error = TemplateSyntaxError("`endif` was not found.")
+        try expect(try parser.parse()).toThrow(error)
+      }
+
+      $0.it("throws an error when parsing an ifnot without an endif") {
+        let tokens: [Token] = [
+            .block(value: "ifnot value"),
+        ]
+
+        let parser = TokenParser(tokens: tokens, namespace: Namespace())
+        let error = TemplateSyntaxError("`endif` was not found.")
+        try expect(try parser.parse()).toThrow(error)
+      }
+    }
+
+    $0.describe("rendering") {
+      $0.it("renders the truth when expression evaluates to true") {
+        let node = IfNode(expression: StaticExpression(value: true), trueNodes: [TextNode(text: "true")], falseNodes: [TextNode(text: "false")])
+        try expect(try node.render(Context())) == "true"
+      }
+
+      $0.it("renders the false when expression evaluates to false") {
+        let node = IfNode(expression: StaticExpression(value: false), trueNodes: [TextNode(text: "true")], falseNodes: [TextNode(text: "false")])
+        try expect(try node.render(Context())) == "false"
+      }
+    }
+  }
+}

Tests/StencilTests/IncludeSpec.swift

@@ -1,16 +1,16 @@
 import Spectre
-import Stencil
+@testable import Stencil
 import PathKit
 
 
 func testInclude() {
   describe("Include") {
-    let path = Path(__FILE__) + ".." + ".." + "fixtures"
-    let loader = TemplateLoader(paths: [path])
+    let path = Path(#file) + ".." + "fixtures"
+    let loader = FileSystemLoader(paths: [path])
 
     $0.describe("parsing") {
       $0.it("throws an error when no template is given") {
-        let tokens = [ Token.Block(value: "include") ]
+        let tokens: [Token] = [ .block(value: "include") ]
         let parser = TokenParser(tokens: tokens, namespace: Namespace())
 
         let error = TemplateSyntaxError("'include' tag takes one argument, the template file to be included")
@@ -18,7 +18,7 @@ func testInclude() {
       }
 
       $0.it("can parse a valid include block") {
-        let tokens = [ Token.Block(value: "include \"test.html\"") ]
+        let tokens: [Token] = [ .block(value: "include \"test.html\"") ]
         let parser = TokenParser(tokens: tokens, namespace: Namespace())
 
         let nodes = try parser.parse()
@@ -33,7 +33,7 @@ func testInclude() {
         let node = IncludeNode(templateName: Variable("\"test.html\""))
 
         do {
-          try node.render(Context())
+          _ = try node.render(Context())
         } catch {
           try expect("\(error)") == "Template loader not in context"
         }
@@ -43,7 +43,7 @@ func testInclude() {
         let node = IncludeNode(templateName: Variable("\"unknown.html\""))
 
         do {
-          try node.render(Context(dictionary: ["loader": loader]))
+          _ = try node.render(Context(dictionary: ["loader": loader]))
         } catch {
           try expect("\(error)".hasPrefix("'unknown.html' template not found")).to.beTrue()
         }

Tests/StencilTests/InheritenceSpec.swift

@@ -0,0 +1,23 @@
+import Spectre
+import Stencil
+import PathKit
+
+
+func testInheritence() {
+  describe("Inheritence") {
+    let path = Path(#file) + ".." + "fixtures"
+    let loader = FileSystemLoader(paths: [path])
+
+    $0.it("can inherit from another template") {
+      let context = Context(dictionary: ["loader": loader])
+      let template = try loader.loadTemplate(name: "child.html")
+      try expect(try template?.render(context)) == "Header\nChild"
+    }
+
+    $0.it("can inherit from another template inheriting from another template") {
+      let context = Context(dictionary: ["loader": loader])
+      let template = try loader.loadTemplate(name: "child-child.html")
+      try expect(try template?.render(context)) == "Child Child Header\nChild"
+    }
+  }
+}

Tests/StencilTests/LexerSpec.swift

@@ -1,5 +1,5 @@
 import Spectre
-import Stencil
+@testable import Stencil
 
 
 func testLexer() {
@@ -9,7 +9,7 @@ func testLexer() {
       let tokens = lexer.tokenize()
 
       try expect(tokens.count) == 1
-      try expect(tokens.first) == Token.Text(value: "Hello World")
+      try expect(tokens.first) == .text(value: "Hello World")
     }
 
     $0.it("can tokenize a comment") {
@@ -17,7 +17,7 @@ func testLexer() {
       let tokens = lexer.tokenize()
 
       try expect(tokens.count) == (1)
-      try expect(tokens.first) == Token.Comment(value: "Comment")
+      try expect(tokens.first) == .comment(value: "Comment")
     }
 
     $0.it("can tokenize a variable") {
@@ -25,7 +25,7 @@ func testLexer() {
       let tokens = lexer.tokenize()
 
       try expect(tokens.count) == 1
-      try expect(tokens.first) == Token.Variable(value: "Variable")
+      try expect(tokens.first) == .variable(value: "Variable")
     }
 
     $0.it("can tokenize a mixture of content") {
@@ -33,9 +33,9 @@ func testLexer() {
       let tokens = lexer.tokenize()
 
       try expect(tokens.count) == 3
-      try expect(tokens[0]) == Token.Text(value: "My name is ")
-      try expect(tokens[1]) == Token.Variable(value: "name")
-      try expect(tokens[2]) == Token.Text(value: ".")
+      try expect(tokens[0]) == Token.text(value: "My name is ")
+      try expect(tokens[1]) == Token.variable(value: "name")
+      try expect(tokens[2]) == Token.text(value: ".")
     }
 
     $0.it("can tokenize two variables without being greedy") {
@@ -43,8 +43,8 @@ func testLexer() {
       let tokens = lexer.tokenize()
 
       try expect(tokens.count) == 2
-      try expect(tokens[0]) == Token.Variable(value: "thing")
-      try expect(tokens[1]) == Token.Variable(value: "name")
+      try expect(tokens[0]) == Token.variable(value: "thing")
+      try expect(tokens[1]) == Token.variable(value: "name")
     }
   }
 }

Tests/StencilTests/NodeSpec.swift

@@ -3,7 +3,7 @@ import Stencil
 
 
 class ErrorNode : NodeType {
-  func render(context: Context) throws -> String {
+  func render(_ context: Context) throws -> String {
     throw TemplateSyntaxError("Custom Error")
   }
 }

Tests/StencilTests/NowNodeSpec.swift

@@ -1,6 +1,6 @@
 import Foundation
 import Spectre
-import Stencil
+@testable import Stencil
 
 
 func testNowNode() {
@@ -8,7 +8,7 @@ func testNowNode() {
   describe("NowNode") {
     $0.describe("parsing") {
       $0.it("parses default format without any now arguments") {
-        let tokens = [ Token.Block(value: "now") ]
+        let tokens: [Token] = [ .block(value: "now") ]
         let parser = TokenParser(tokens: tokens, namespace: Namespace())
 
         let nodes = try parser.parse()
@@ -18,7 +18,7 @@ func testNowNode() {
       }
 
       $0.it("parses now with a format") {
-        let tokens = [ Token.Block(value: "now \"HH:mm\"") ]
+        let tokens: [Token] = [ .block(value: "now \"HH:mm\"") ]
         let parser = TokenParser(tokens: tokens, namespace: Namespace())
         let nodes = try parser.parse()
         let node = nodes.first as? NowNode
@@ -31,9 +31,9 @@ func testNowNode() {
       $0.it("renders the date") {
         let node = NowNode(format: Variable("\"yyyy-MM-dd\""))
 
-        let formatter = NSDateFormatter()
+        let formatter = DateFormatter()
         formatter.dateFormat = "yyyy-MM-dd"
-        let date = formatter.stringFromDate(NSDate())
+        let date = formatter.string(from: NSDate() as Date)
 
         try expect(try node.render(Context())) == date
       }

Tests/StencilTests/ParserSpec.swift

@@ -6,7 +6,7 @@ func testTokenParser() {
   describe("TokenParser") {
     $0.it("can parse a text token") {
       let parser = TokenParser(tokens: [
-        Token.Text(value: "Hello World")
+        .text(value: "Hello World")
       ], namespace: Namespace())
 
       let nodes = try parser.parse()
@@ -18,7 +18,7 @@ func testTokenParser() {
 
     $0.it("can parse a variable token") {
       let parser = TokenParser(tokens: [
-        Token.Variable(value: "'name'")
+        .variable(value: "'name'")
       ], namespace: Namespace())
 
       let nodes = try parser.parse()
@@ -30,7 +30,7 @@ func testTokenParser() {
 
     $0.it("can parse a comment token") {
       let parser = TokenParser(tokens: [
-        Token.Comment(value: "Secret stuff!")
+        .comment(value: "Secret stuff!")
       ], namespace: Namespace())
 
       let nodes = try parser.parse()
@@ -44,7 +44,7 @@ func testTokenParser() {
       }
 
       let parser = TokenParser(tokens: [
-        Token.Block(value: "known"),
+        .block(value: "known"),
       ], namespace: namespace)
 
       let nodes = try parser.parse()
@@ -53,7 +53,7 @@ func testTokenParser() {
 
     $0.it("errors when parsing an unknown tag") {
       let parser = TokenParser(tokens: [
-        Token.Block(value: "unknown"),
+        .block(value: "unknown"),
       ], namespace: Namespace())
 
       try expect(try parser.parse()).toThrow(TemplateSyntaxError("Unknown template tag 'unknown'"))

Tests/StencilTests/StencilSpec.swift

@@ -2,16 +2,23 @@ import Spectre
 import Stencil
 
 
-class CustomNode : NodeType {
-  func render(context:Context) throws -> String {
+fileprivate class CustomNode : NodeType {
+  func render(_ context:Context) throws -> String {
     return "Hello World"
   }
 }
 
 
+fileprivate struct Article {
+  let title: String
+  let author: String
+}
+
+
 func testStencil() {
   describe("Stencil") {
     $0.it("can render the README example") {
+
       let templateString = "There are {{ articles.count }} articles.\n" +
         "\n" +
         "{% for article in articles %}" +
@@ -20,8 +27,8 @@ func testStencil() {
 
       let context = Context(dictionary: [
         "articles": [
-          [ "title": "Migrating from OCUnit to XCTest", "author": "Kyle Fuller" ],
-          [ "title": "Memory Management with ARC", "author": "Kyle Fuller" ],
+          Article(title: "Migrating from OCUnit to XCTest", author: "Kyle Fuller"),
+          Article(title: "Memory Management with ARC", author: "Kyle Fuller"),
         ]
       ])
 

Tests/StencilTests/TemplateLoaderSpec.swift

@@ -5,19 +5,19 @@ import PathKit
 
 func testTemplateLoader() {
   describe("TemplateLoader") {
-    let path = Path(__FILE__) + ".." + ".." + "Tests" + "fixtures"
-    let loader = TemplateLoader(paths: [path])
+    let path = Path(#file) + ".."  + "fixtures"
+    let loader = FileSystemLoader(paths: [path])
 
     $0.it("returns nil when a template cannot be found") {
-      try expect(loader.loadTemplate("unknown.html")).to.beNil()
+      try expect(try loader.loadTemplate(name: "unknown.html")).to.beNil()
     }
 
     $0.it("returns nil when an array of templates cannot be found") {
-      try expect(loader.loadTemplate(["unknown.html", "unknown2.html"])).to.beNil()
+      try expect(try loader.loadTemplate(names: ["unknown.html", "unknown2.html"])).to.beNil()
     }
 
     $0.it("can load a template from a file") {
-      if loader.loadTemplate("test.html") == nil {
+      if try loader.loadTemplate(name: "test.html") == nil {
         throw failure("didn't find the template")
       }
     }

Tests/StencilTests/TemplateSpec.swift

@@ -10,5 +10,12 @@ func testTemplate() {
       let result = try template.render(context)
       try expect(result) == "Hello World"
     }
+
+    $0.it("can render a template from a string literal") {
+        let context = Context(dictionary: [ "name": "Kyle" ])
+        let template: Template = "Hello World"
+        let result = try template.render(context)
+        try expect(result) == "Hello World"
+    }
   }
 }

Tests/StencilTests/TokenSpec.swift

@@ -5,7 +5,7 @@ import Stencil
 func testToken() {
   describe("Token") {
     $0.it("can split the contents into components") {
-      let token = Token.Text(value: "hello world")
+      let token = Token.text(value: "hello world")
       let components = token.components()
 
       try expect(components.count) == 2
@@ -14,7 +14,7 @@ func testToken() {
     }
 
     $0.it("can split the contents into components with single quoted strings") {
-      let token = Token.Text(value: "hello 'kyle fuller'")
+      let token = Token.text(value: "hello 'kyle fuller'")
       let components = token.components()
 
       try expect(components.count) == 2
@@ -23,7 +23,7 @@ func testToken() {
     }
 
     $0.it("can split the contents into components with double quoted strings") {
-      let token = Token.Text(value: "hello \"kyle fuller\"")
+      let token = Token.text(value: "hello \"kyle fuller\"")
       let components = token.components()
 
       try expect(components.count) == 2

Tests/StencilTests/VariableSpec.swift

@@ -9,6 +9,14 @@ import Stencil
 }
 #endif
 
+fileprivate struct Person {
+  let name: String
+}
+
+fileprivate struct Article {
+  let author: Person
+}
+
 
 func testVariable() {
   describe("Variable") {
@@ -18,6 +26,7 @@ func testVariable() {
       "profiles": [
         "github": "kylef",
       ],
+      "article": Article(author: Person(name: "Kyle"))
     ])
 
 #if os(OSX)
@@ -52,6 +61,20 @@ func testVariable() {
       let variable = Variable("contacts.0")
       let result = try variable.resolve(context) as? String
       try expect(result) == "Katie"
+
+        let variable1 = Variable("contacts.1")
+        let result1 = try variable1.resolve(context) as? String
+        try expect(result1) == "Carlton"
+    }
+
+    $0.it("can resolve an item from an array via unknown index") {
+      let variable = Variable("contacts.5")
+      let result = try variable.resolve(context) as? String
+      try expect(result).to.beNil()
+
+      let variable1 = Variable("contacts.-5")
+      let result1 = try variable1.resolve(context) as? String
+      try expect(result1).to.beNil()
     }
 
     $0.it("can resolve the first item from an array") {
@@ -66,6 +89,12 @@ func testVariable() {
       try expect(result) == "Carlton"
     }
 
+    $0.it("can resolve a property with reflection") {
+      let variable = Variable("article.author.name")
+      let result = try variable.resolve(context) as? String
+      try expect(result) == "Kyle"
+    }
+
 #if os(OSX)
     $0.it("can resolve a value via KVO") {
       let variable = Variable("object.title")

Tests/StencilTests/XCTest.swift

@@ -0,0 +1,28 @@
+import XCTest
+
+
+public func stencilTests() {
+  testContext()
+  testFilter()
+  testLexer()
+  testToken()
+  testTokenParser()
+  testTemplateLoader()
+  testTemplate()
+  testVariable()
+  testNode()
+  testForNode()
+  testExpressions()
+  testIfNode()
+  testNowNode()
+  testInclude()
+  testInheritence()
+  testStencil()
+}
+
+
+class StencilTests: XCTestCase {
+  func testRunStencilTests() {
+    stencilTests()
+  }
+}

Tests/StencilTests/fixtures/child-child.html

@@ -0,0 +1,2 @@
+{% extends "child.html" %}
+{% block header %}Child Child Header{% endblock %}

Tests/TemplateLoader/InheritenceSpec.swift

@@ -1,17 +0,0 @@
-import Spectre
-import Stencil
-import PathKit
-
-
-func testInheritence() {
-  describe("Inheritence") {
-    let path = Path(__FILE__) + ".." + ".." + "fixtures"
-    let loader = TemplateLoader(paths: [path])
-
-    $0.it("can inherit from another template") {
-      let context = Context(dictionary: ["loader": loader])
-      let template = loader.loadTemplate("child.html")
-      try expect(try template?.render(context)) == "Header\nChild"
-    }
-  }
-}

Tests/main.swift

@@ -1,15 +0,0 @@
-testContext()
-testFilter()
-testLexer()
-testToken()
-testTokenParser()
-testTemplateLoader()
-testTemplate()
-testVariable()
-testNode()
-testForNode()
-testIfNode()
-testNowNode()
-testInclude()
-testInheritence()
-testStencil()

docs/Makefile

@@ -0,0 +1,225 @@
+# Makefile for Sphinx documentation
+#
+
+# You can set these variables from the command line.
+SPHINXOPTS    =
+SPHINXBUILD   = sphinx-build
+PAPER         =
+BUILDDIR      = _build
+
+# Internal variables.
+PAPEROPT_a4     = -D latex_paper_size=a4
+PAPEROPT_letter = -D latex_paper_size=letter
+ALLSPHINXOPTS   = -d $(BUILDDIR)/doctrees $(PAPEROPT_$(PAPER)) $(SPHINXOPTS) .
+# the i18n builder cannot share the environment and doctrees with the others
+I18NSPHINXOPTS  = $(PAPEROPT_$(PAPER)) $(SPHINXOPTS) .
+
+.PHONY: help
+help:
+	@echo "Please use \`make <target>' where <target> is one of"
+	@echo "  html       to make standalone HTML files"
+	@echo "  dirhtml    to make HTML files named index.html in directories"
+	@echo "  singlehtml to make a single large HTML file"
+	@echo "  pickle     to make pickle files"
+	@echo "  json       to make JSON files"
+	@echo "  htmlhelp   to make HTML files and a HTML help project"
+	@echo "  qthelp     to make HTML files and a qthelp project"
+	@echo "  applehelp  to make an Apple Help Book"
+	@echo "  devhelp    to make HTML files and a Devhelp project"
+	@echo "  epub       to make an epub"
+	@echo "  epub3      to make an epub3"
+	@echo "  latex      to make LaTeX files, you can set PAPER=a4 or PAPER=letter"
+	@echo "  latexpdf   to make LaTeX files and run them through pdflatex"
+	@echo "  latexpdfja to make LaTeX files and run them through platex/dvipdfmx"
+	@echo "  text       to make text files"
+	@echo "  man        to make manual pages"
+	@echo "  texinfo    to make Texinfo files"
+	@echo "  info       to make Texinfo files and run them through makeinfo"
+	@echo "  gettext    to make PO message catalogs"
+	@echo "  changes    to make an overview of all changed/added/deprecated items"
+	@echo "  xml        to make Docutils-native XML files"
+	@echo "  pseudoxml  to make pseudoxml-XML files for display purposes"
+	@echo "  linkcheck  to check all external links for integrity"
+	@echo "  doctest    to run all doctests embedded in the documentation (if enabled)"
+	@echo "  coverage   to run coverage check of the documentation (if enabled)"
+	@echo "  dummy      to check syntax errors of document sources"
+
+.PHONY: clean
+clean:
+	rm -rf $(BUILDDIR)/*
+
+.PHONY: html
+html:
+	$(SPHINXBUILD) -b html $(ALLSPHINXOPTS) $(BUILDDIR)/html
+	@echo
+	@echo "Build finished. The HTML pages are in $(BUILDDIR)/html."
+
+.PHONY: dirhtml
+dirhtml:
+	$(SPHINXBUILD) -b dirhtml $(ALLSPHINXOPTS) $(BUILDDIR)/dirhtml
+	@echo
+	@echo "Build finished. The HTML pages are in $(BUILDDIR)/dirhtml."
+
+.PHONY: singlehtml
+singlehtml:
+	$(SPHINXBUILD) -b singlehtml $(ALLSPHINXOPTS) $(BUILDDIR)/singlehtml
+	@echo
+	@echo "Build finished. The HTML page is in $(BUILDDIR)/singlehtml."
+
+.PHONY: pickle
+pickle:
+	$(SPHINXBUILD) -b pickle $(ALLSPHINXOPTS) $(BUILDDIR)/pickle
+	@echo
+	@echo "Build finished; now you can process the pickle files."
+
+.PHONY: json
+json:
+	$(SPHINXBUILD) -b json $(ALLSPHINXOPTS) $(BUILDDIR)/json
+	@echo
+	@echo "Build finished; now you can process the JSON files."
+
+.PHONY: htmlhelp
+htmlhelp:
+	$(SPHINXBUILD) -b htmlhelp $(ALLSPHINXOPTS) $(BUILDDIR)/htmlhelp
+	@echo
+	@echo "Build finished; now you can run HTML Help Workshop with the" \
+	      ".hhp project file in $(BUILDDIR)/htmlhelp."
+
+.PHONY: qthelp
+qthelp:
+	$(SPHINXBUILD) -b qthelp $(ALLSPHINXOPTS) $(BUILDDIR)/qthelp
+	@echo
+	@echo "Build finished; now you can run "qcollectiongenerator" with the" \
+	      ".qhcp project file in $(BUILDDIR)/qthelp, like this:"
+	@echo "# qcollectiongenerator $(BUILDDIR)/qthelp/Stencil.qhcp"
+	@echo "To view the help file:"
+	@echo "# assistant -collectionFile $(BUILDDIR)/qthelp/Stencil.qhc"
+
+.PHONY: applehelp
+applehelp:
+	$(SPHINXBUILD) -b applehelp $(ALLSPHINXOPTS) $(BUILDDIR)/applehelp
+	@echo
+	@echo "Build finished. The help book is in $(BUILDDIR)/applehelp."
+	@echo "N.B. You won't be able to view it unless you put it in" \
+	      "~/Library/Documentation/Help or install it in your application" \
+	      "bundle."
+
+.PHONY: devhelp
+devhelp:
+	$(SPHINXBUILD) -b devhelp $(ALLSPHINXOPTS) $(BUILDDIR)/devhelp
+	@echo
+	@echo "Build finished."
+	@echo "To view the help file:"
+	@echo "# mkdir -p $$HOME/.local/share/devhelp/Stencil"
+	@echo "# ln -s $(BUILDDIR)/devhelp $$HOME/.local/share/devhelp/Stencil"
+	@echo "# devhelp"
+
+.PHONY: epub
+epub:
+	$(SPHINXBUILD) -b epub $(ALLSPHINXOPTS) $(BUILDDIR)/epub
+	@echo
+	@echo "Build finished. The epub file is in $(BUILDDIR)/epub."
+
+.PHONY: epub3
+epub3:
+	$(SPHINXBUILD) -b epub3 $(ALLSPHINXOPTS) $(BUILDDIR)/epub3
+	@echo
+	@echo "Build finished. The epub3 file is in $(BUILDDIR)/epub3."
+
+.PHONY: latex
+latex:
+	$(SPHINXBUILD) -b latex $(ALLSPHINXOPTS) $(BUILDDIR)/latex
+	@echo
+	@echo "Build finished; the LaTeX files are in $(BUILDDIR)/latex."
+	@echo "Run \`make' in that directory to run these through (pdf)latex" \
+	      "(use \`make latexpdf' here to do that automatically)."
+
+.PHONY: latexpdf
+latexpdf:
+	$(SPHINXBUILD) -b latex $(ALLSPHINXOPTS) $(BUILDDIR)/latex
+	@echo "Running LaTeX files through pdflatex..."
+	$(MAKE) -C $(BUILDDIR)/latex all-pdf
+	@echo "pdflatex finished; the PDF files are in $(BUILDDIR)/latex."
+
+.PHONY: latexpdfja
+latexpdfja:
+	$(SPHINXBUILD) -b latex $(ALLSPHINXOPTS) $(BUILDDIR)/latex
+	@echo "Running LaTeX files through platex and dvipdfmx..."
+	$(MAKE) -C $(BUILDDIR)/latex all-pdf-ja
+	@echo "pdflatex finished; the PDF files are in $(BUILDDIR)/latex."
+
+.PHONY: text
+text:
+	$(SPHINXBUILD) -b text $(ALLSPHINXOPTS) $(BUILDDIR)/text
+	@echo
+	@echo "Build finished. The text files are in $(BUILDDIR)/text."
+
+.PHONY: man
+man:
+	$(SPHINXBUILD) -b man $(ALLSPHINXOPTS) $(BUILDDIR)/man
+	@echo
+	@echo "Build finished. The manual pages are in $(BUILDDIR)/man."
+
+.PHONY: texinfo
+texinfo:
+	$(SPHINXBUILD) -b texinfo $(ALLSPHINXOPTS) $(BUILDDIR)/texinfo
+	@echo
+	@echo "Build finished. The Texinfo files are in $(BUILDDIR)/texinfo."
+	@echo "Run \`make' in that directory to run these through makeinfo" \
+	      "(use \`make info' here to do that automatically)."
+
+.PHONY: info
+info:
+	$(SPHINXBUILD) -b texinfo $(ALLSPHINXOPTS) $(BUILDDIR)/texinfo
+	@echo "Running Texinfo files through makeinfo..."
+	make -C $(BUILDDIR)/texinfo info
+	@echo "makeinfo finished; the Info files are in $(BUILDDIR)/texinfo."
+
+.PHONY: gettext
+gettext:
+	$(SPHINXBUILD) -b gettext $(I18NSPHINXOPTS) $(BUILDDIR)/locale
+	@echo
+	@echo "Build finished. The message catalogs are in $(BUILDDIR)/locale."
+
+.PHONY: changes
+changes:
+	$(SPHINXBUILD) -b changes $(ALLSPHINXOPTS) $(BUILDDIR)/changes
+	@echo
+	@echo "The overview file is in $(BUILDDIR)/changes."
+
+.PHONY: linkcheck
+linkcheck:
+	$(SPHINXBUILD) -b linkcheck $(ALLSPHINXOPTS) $(BUILDDIR)/linkcheck
+	@echo
+	@echo "Link check complete; look for any errors in the above output " \
+	      "or in $(BUILDDIR)/linkcheck/output.txt."
+
+.PHONY: doctest
+doctest:
+	$(SPHINXBUILD) -b doctest $(ALLSPHINXOPTS) $(BUILDDIR)/doctest
+	@echo "Testing of doctests in the sources finished, look at the " \
+	      "results in $(BUILDDIR)/doctest/output.txt."
+
+.PHONY: coverage
+coverage:
+	$(SPHINXBUILD) -b coverage $(ALLSPHINXOPTS) $(BUILDDIR)/coverage
+	@echo "Testing of coverage in the sources finished, look at the " \
+	      "results in $(BUILDDIR)/coverage/python.txt."
+
+.PHONY: xml
+xml:
+	$(SPHINXBUILD) -b xml $(ALLSPHINXOPTS) $(BUILDDIR)/xml
+	@echo
+	@echo "Build finished. The XML files are in $(BUILDDIR)/xml."
+
+.PHONY: pseudoxml
+pseudoxml:
+	$(SPHINXBUILD) -b pseudoxml $(ALLSPHINXOPTS) $(BUILDDIR)/pseudoxml
+	@echo
+	@echo "Build finished. The pseudo-XML files are in $(BUILDDIR)/pseudoxml."
+
+.PHONY: dummy
+dummy:
+	$(SPHINXBUILD) -b dummy $(ALLSPHINXOPTS) $(BUILDDIR)/dummy
+	@echo
+	@echo "Build finished. Dummy builder generates no files."

docs/_templates/sidebar_intro.html

@@ -0,0 +1,33 @@
+<h1><a href="/">Stencil</a></h1>
+
+<p>
+  <iframe
+      src="https://ghbtns.com/github-btn.html?user=kylef&repo=Stencil&type=watch&count=true&size=large"
+      allowtransparency="true" frameborder="0" scrolling="0" width="200px" height="35px">
+  </iframe>
+</p>
+
+<p>Stencil is a simple and powerful template language for Swift.</p>
+
+<div class="social">
+  <p>
+    <iframe
+      src="https://ghbtns.com/github-btn.html?user=kylef&type=follow&count=false"
+      allowtransparency="true" frameborder="0" scrolling="0" width="200" height="20">
+    </iframe>
+  </p>
+
+  <p>
+    <a href="https://twitter.com/kylefuller" class="twitter-follow-button" data-show-count="false">Follow @kylefuller</a> <script>!function(d,s,id){var js,fjs=d.getElementsByTagName(s)[0],p=/^http:/.test(d.location)?'http':'https';if(!d.getElementById(id)){js=d.createElement(s);js.id=id;js.src=p+'://platform.twitter.com/widgets.js';fjs.parentNode.insertBefore(js,fjs);}}(document, 'script', 'twitter-wjs');</script>
+  </p>
+</div>
+
+<h3>Other Projects</h3>
+
+<p>More <a href="https://fuller.li/">Kyle Fuller</a> projects:</p>
+<ul>
+  <li><a href="https://github.com/kylef/Commander">Commander</a></li>
+  <li><a href="https://curassow.fuller.li/">Curassow</a></li>
+  <li><a href="https://github.com/kylef/Spectre">Spectre</a></li>
+  <li><a href="https://github.com/kylef/heroku-buildpack-swift">Heroku Swift buildpack</a></li>
+</ul>

docs/api/context.rst

@@ -0,0 +1,51 @@
+Context
+=======
+
+A Context is a structure containing any templates you would like to use in a
+template. It’s somewhat like a dictionary, however you can push and pop to
+scope variables. So that means that when iterating over a for loop, you can
+push a new scope into the context to store any variables local to the scope.
+
+You can initialise a ``Context`` with a ``Dictionary``.
+
+.. code-block:: swift
+
+    Context(dictionary: [String: Any]? = nil)
+
+API
+----
+
+Subscripting
+~~~~~~~~~~~~
+
+You can use subscripting to get and set values from the context.
+
+.. code-block:: swift
+
+    context["key"] = value
+    let value = context["key"]
+
+``push()``
+~~~~~~~~~~
+
+A ``Context`` is a stack. You can push a new level onto the ``Context`` so that
+modifications can easily be poped off. This is useful for isolating mutations
+into scope of a template tag. Such as ``{% if %}`` and ``{% for %}`` tags.
+
+.. code-block:: swift
+
+    context.push(["name": "example"]) {
+        // context contains name which is `example`.
+    }
+
+    // name is popped off the context after the duration of the closure.
+
+``flatten()``
+~~~~~~~~~~~~~
+
+Using ``flatten()`` method you can get whole ``Context`` stack as one
+dictionary including all variables.
+
+.. code-block:: swift
+
+    let dictionary = context.flatten()

docs/builtins.rst

@@ -0,0 +1,257 @@
+Built-in template tags and filters
+==================================
+
+.. _built-in-tags:
+
+Built-in Tags
+-------------
+
+``for``
+~~~~~~~
+
+A for loop allows you to iterate over an array found by variable lookup.
+
+.. code-block:: html+django
+
+    <ul>
+      {% for user in users %}
+        <li>{{ user }}</li>
+      {% endfor %}
+    </ul>
+
+The ``for`` tag can take an optional ``{% empty %}`` block that will be
+displayed if the given list is empty or could not be found.
+
+.. code-block:: html+django
+
+    <ul>
+      {% for user in users %}
+        <li>{{ user }}</li>
+      {% empty %}
+        <li>There are no users.</li>
+      {% endfor %}
+    </ul>
+
+The for block sets a few variables available within the loop:
+
+- ``first`` - True if this is the first time through the loop
+- ``last`` - True if this is the last time through the loop
+- ``counter`` - The current iteration of the loop
+
+``if``
+~~~~~~
+
+The ``{% if %}`` tag evaluates a variable, and if that variable evaluates to
+true the contents of the block are processed. Being true is defined as:
+
+* Present in the context
+* Being non-empty (dictionaries or arrays)
+* Not being a false boolean value
+* Not being a numerical value of 0 or below
+* Not being an empty string
+
+.. code-block:: html+django
+
+    {% if variable %}
+      The variable was found in the current context.
+    {% else %}
+      The variable was not found.
+    {% endif %}
+
+Operators
+^^^^^^^^^
+
+``if`` tags may combine ``and``, ``or`` and ``not`` to test multiple variables
+or to negate a variable.
+
+.. code-block:: html+django
+
+    {% if one and two %}
+        Both one and two evaluate to true.
+    {% endif %}
+
+    {% if not one %}
+        One evaluates to false
+    {% endif %}
+
+    {% if one or two %}
+        Either one or two evaluates to true.
+    {% endif %}
+
+    {% if not one or two %}
+        One does not evaluate to false or two evaluates to true.
+    {% endif %}
+
+You may use ``and``, ``or`` and ``not`` multiple times together. ``not`` has
+higest prescidence followed by ``and``. For example:
+
+.. code-block:: html+django
+
+    {% if one or two and three %}
+
+Will be treated as:
+
+.. code-block:: text
+
+    one or (two and three)
+
+``==`` operator
+"""""""""""""""
+
+.. code-block:: html+django
+
+    {% if value == other_value %}
+      value is equal to other_value
+    {% endif %}
+
+.. note:: The equality operator only supports numerical, string and boolean types.
+
+``!=`` operator
+"""""""""""""""
+
+.. code-block:: html+django
+
+    {% if value != other_value %}
+      value is not equal to other_value
+    {% endif %}
+
+.. note:: The inequality operator only supports numerical, string and boolean types.
+
+``<`` operator
+"""""""""""""""
+
+.. code-block:: html+django
+
+    {% if value < other_value %}
+      value is less than other_value
+    {% endif %}
+
+.. note:: The less than operator only supports numerical types.
+
+``<=`` operator
+"""""""""""""""
+
+.. code-block:: html+django
+
+    {% if value <= other_value %}
+      value is less than or equal to other_value
+    {% endif %}
+
+.. note:: The less than equal operator only supports numerical types.
+
+``>`` operator
+"""""""""""""""
+
+.. code-block:: html+django
+
+    {% if value > other_value %}
+      value is more than other_value
+    {% endif %}
+
+.. note:: The more than operator only supports numerical types.
+
+``>=`` operator
+"""""""""""""""
+
+.. code-block:: html+django
+
+    {% if value >= other_value %}
+      value is more than or equal to other_value
+    {% endif %}
+
+.. note:: The more than equal operator only supports numerical types.
+
+``ifnot``
+~~~~~~~~~
+
+.. note:: ``{% ifnot %}`` is deprecated. You should use ``{% if not %}``.
+
+.. code-block:: html+django
+
+    {% ifnot variable %}
+      The variable was NOT found in the current context.
+    {% else %}
+      The variable was found.
+    {% endif %}
+
+``now``
+~~~~~~~
+
+``include``
+~~~~~~~~~~~
+
+You can include another template using the `include` tag.
+
+.. code-block:: html+django
+
+    {% include "comment.html" %}
+
+The `include` tag requires a FileSystemLoader to be found inside your context with the paths, or bundles used to lookup the template.
+
+.. code-block:: swift
+
+    let context = Context(dictionary: [
+      "loader": FileSystemLoader(bundle: [NSBundle.mainBundle()])
+    ])
+
+``extends``
+~~~~~~~~~~~
+
+``block``
+~~~~~~~~~
+
+.. _built-in-filters:
+
+Built-in Filters
+----------------
+
+``capitalize``
+~~~~~~~~~~~~~~
+
+The capitalize filter allows you to capitalize a string.
+For example, `stencil` to `Stencil`.
+
+.. code-block:: html+django
+
+    {{ "stencil"|capitalize }}
+
+``uppercase``
+~~~~~~~~~~~~~
+
+The uppercase filter allows you to transform a string to uppercase.
+For example, `Stencil` to `STENCIL`.
+
+.. code-block:: html+django
+
+    {{ "Stencil"|uppercase }}
+
+``lowercase``
+~~~~~~~~~~~~~
+
+The uppercase filter allows you to transform a string to lowercase.
+For example, `Stencil` to `stencil`.
+
+.. code-block:: html+django
+
+    {{ "Stencil"|lowercase }}
+
+``default``
+~~~~~~~~~~~
+
+If a variable not present in the context, use given default. Otherwise, use the
+value of the variable. For example:
+
+.. code-block:: html+django
+
+    Hello {{ name|default:"World" }}
+
+``join``
+~~~~~~~~
+
+Join an array with a string.
+
+.. code-block:: html+django
+
+    {{ value|join:", " }}
+
+.. note:: The value MUST be an array of Strngs and the separator must be a string.

docs/conf.py

@@ -0,0 +1,341 @@
+#!/usr/bin/env python3
+# -*- coding: utf-8 -*-
+#
+# Stencil documentation build configuration file, created by
+# sphinx-quickstart on Sun Nov 27 05:54:36 2016.
+#
+# This file is execfile()d with the current directory set to its
+# containing dir.
+#
+# Note that not all possible configuration values are present in this
+# autogenerated file.
+#
+# All configuration values have a default; values that are commented out
+# serve to show the default.
+
+# If extensions (or modules to document with autodoc) are in another directory,
+# add these directories to sys.path here. If the directory is relative to the
+# documentation root, use os.path.abspath to make it absolute, like shown here.
+#
+# import os
+# import sys
+# sys.path.insert(0, os.path.abspath('.'))
+
+# -- General configuration ------------------------------------------------
+
+# If your documentation needs a minimal Sphinx version, state it here.
+#
+# needs_sphinx = '1.0'
+
+# Add any Sphinx extension module names here, as strings. They can be
+# extensions coming with Sphinx (named 'sphinx.ext.*') or your custom
+# ones.
+extensions = []
+
+# Add any paths that contain templates here, relative to this directory.
+templates_path = ['_templates']
+
+# The suffix(es) of source filenames.
+# You can specify multiple suffix as a list of string:
+#
+# source_suffix = ['.rst', '.md']
+source_suffix = '.rst'
+
+# The encoding of source files.
+#
+# source_encoding = 'utf-8-sig'
+
+# The master toctree document.
+master_doc = 'index'
+
+# General information about the project.
+project = 'Stencil'
+copyright = '2016, Kyle Fuller'
+author = 'Kyle Fuller'
+
+# The version info for the project you're documenting, acts as replacement for
+# |version| and |release|, also used in various other places throughout the
+# built documents.
+#
+# The short X.Y version.
+version = '0.7.0'
+# The full version, including alpha/beta/rc tags.
+release = '0.7.0'
+
+# The language for content autogenerated by Sphinx. Refer to documentation
+# for a list of supported languages.
+#
+# This is also used if you do content translation via gettext catalogs.
+# Usually you set "language" from the command line for these cases.
+language = None
+
+# There are two options for replacing |today|: either, you set today to some
+# non-false value, then it is used:
+#
+# today = ''
+#
+# Else, today_fmt is used as the format for a strftime call.
+#
+# today_fmt = '%B %d, %Y'
+
+# List of patterns, relative to source directory, that match files and
+# directories to ignore when looking for source files.
+# This patterns also effect to html_static_path and html_extra_path
+exclude_patterns = ['_build', 'Thumbs.db', '.DS_Store']
+
+# The reST default role (used for this markup: `text`) to use for all
+# documents.
+#
+# default_role = None
+
+# If true, '()' will be appended to :func: etc. cross-reference text.
+#
+# add_function_parentheses = True
+
+# If true, the current module name will be prepended to all description
+# unit titles (such as .. function::).
+#
+# add_module_names = True
+
+# If true, sectionauthor and moduleauthor directives will be shown in the
+# output. They are ignored by default.
+#
+# show_authors = False
+
+# The name of the Pygments (syntax highlighting) style to use.
+pygments_style = 'sphinx'
+
+# A list of ignored prefixes for module index sorting.
+# modindex_common_prefix = []
+
+# If true, keep warnings as "system message" paragraphs in the built documents.
+# keep_warnings = False
+
+# If true, `todo` and `todoList` produce output, else they produce nothing.
+todo_include_todos = False
+
+
+# -- Options for HTML output ----------------------------------------------
+
+# The theme to use for HTML and HTML Help pages.  See the documentation for
+# a list of builtin themes.
+#
+html_theme = 'alabaster'
+
+# Theme options are theme-specific and customize the look and feel of a theme
+# further.  For a list of options available for each theme, see the
+# documentation.
+#
+# html_theme_options = {}
+
+# Add any paths that contain custom themes here, relative to this directory.
+# html_theme_path = []
+
+# The name for this set of Sphinx documents.
+# "<project> v<release> documentation" by default.
+#
+# html_title = 'Stencil v0.6.0'
+
+# A shorter title for the navigation bar.  Default is the same as html_title.
+#
+# html_short_title = None
+
+# The name of an image file (relative to this directory) to place at the top
+# of the sidebar.
+#
+# html_logo = None
+
+# The name of an image file (relative to this directory) to use as a favicon of
+# the docs.  This file should be a Windows icon file (.ico) being 16x16 or 32x32
+# pixels large.
+#
+# html_favicon = None
+
+# Add any paths that contain custom static files (such as style sheets) here,
+# relative to this directory. They are copied after the builtin static files,
+# so a file named "default.css" will overwrite the builtin "default.css".
+html_static_path = ['_static']
+
+# Add any extra paths that contain custom files (such as robots.txt or
+# .htaccess) here, relative to this directory. These files are copied
+# directly to the root of the documentation.
+#
+# html_extra_path = []
+
+# If not None, a 'Last updated on:' timestamp is inserted at every page
+# bottom, using the given strftime format.
+# The empty string is equivalent to '%b %d, %Y'.
+#
+# html_last_updated_fmt = None
+
+# If true, SmartyPants will be used to convert quotes and dashes to
+# typographically correct entities.
+#
+# html_use_smartypants = True
+
+# Custom sidebar templates, maps document names to template names.
+html_sidebars = {
+    'index': ['sidebar_intro.html', 'searchbox.html'],
+    '**': ['sidebar_intro.html', 'localtoc.html', 'relations.html', 'searchbox.html'],
+}
+
+# Additional templates that should be rendered to pages, maps page names to
+# template names.
+#
+# html_additional_pages = {}
+
+# If false, no module index is generated.
+#
+# html_domain_indices = True
+
+# If false, no index is generated.
+#
+# html_use_index = True
+
+# If true, the index is split into individual pages for each letter.
+#
+# html_split_index = False
+
+# If true, links to the reST sources are added to the pages.
+#
+# html_show_sourcelink = True
+
+# If true, "Created using Sphinx" is shown in the HTML footer. Default is True.
+#
+# html_show_sphinx = True
+
+# If true, "(C) Copyright ..." is shown in the HTML footer. Default is True.
+#
+# html_show_copyright = True
+
+# If true, an OpenSearch description file will be output, and all pages will
+# contain a <link> tag referring to it.  The value of this option must be the
+# base URL from which the finished HTML is served.
+#
+# html_use_opensearch = ''
+
+# This is the file name suffix for HTML files (e.g. ".xhtml").
+# html_file_suffix = None
+
+# Language to be used for generating the HTML full-text search index.
+# Sphinx supports the following languages:
+#   'da', 'de', 'en', 'es', 'fi', 'fr', 'h', 'it', 'ja'
+#   'nl', 'no', 'pt', 'ro', 'r', 'sv', 'tr', 'zh'
+#
+# html_search_language = 'en'
+
+# A dictionary with options for the search language support, empty by default.
+# 'ja' uses this config value.
+# 'zh' user can custom change `jieba` dictionary path.
+#
+# html_search_options = {'type': 'default'}
+
+# The name of a javascript file (relative to the configuration directory) that
+# implements a search results scorer. If empty, the default will be used.
+#
+# html_search_scorer = 'scorer.js'
+
+# Output file base name for HTML help builder.
+htmlhelp_basename = 'Stencildoc'
+
+# -- Options for LaTeX output ---------------------------------------------
+
+latex_elements = {
+     # The paper size ('letterpaper' or 'a4paper').
+     #
+     # 'papersize': 'letterpaper',
+
+     # The font size ('10pt', '11pt' or '12pt').
+     #
+     # 'pointsize': '10pt',
+
+     # Additional stuff for the LaTeX preamble.
+     #
+     # 'preamble': '',
+
+     # Latex figure (float) alignment
+     #
+     # 'figure_align': 'htbp',
+}
+
+# Grouping the document tree into LaTeX files. List of tuples
+# (source start file, target name, title,
+#  author, documentclass [howto, manual, or own class]).
+latex_documents = [
+    (master_doc, 'Stencil.tex', 'Stencil Documentation',
+     'Kyle Fuller', 'manual'),
+]
+
+# The name of an image file (relative to this directory) to place at the top of
+# the title page.
+#
+# latex_logo = None
+
+# For "manual" documents, if this is true, then toplevel headings are parts,
+# not chapters.
+#
+# latex_use_parts = False
+
+# If true, show page references after internal links.
+#
+# latex_show_pagerefs = False
+
+# If true, show URL addresses after external links.
+#
+# latex_show_urls = False
+
+# Documents to append as an appendix to all manuals.
+#
+# latex_appendices = []
+
+# It false, will not define \strong, \code, 	itleref, \crossref ... but only
+# \sphinxstrong, ..., \sphinxtitleref, ... To help avoid clash with user added
+# packages.
+#
+# latex_keep_old_macro_names = True
+
+# If false, no module index is generated.
+#
+# latex_domain_indices = True
+
+
+# -- Options for manual page output ---------------------------------------
+
+# One entry per manual page. List of tuples
+# (source start file, name, description, authors, manual section).
+man_pages = [
+    (master_doc, 'stencil', 'Stencil Documentation',
+     [author], 1)
+]
+
+# If true, show URL addresses after external links.
+#
+# man_show_urls = False
+
+
+# -- Options for Texinfo output -------------------------------------------
+
+# Grouping the document tree into Texinfo files. List of tuples
+# (source start file, target name, title, author,
+#  dir menu entry, description, category)
+texinfo_documents = [
+    (master_doc, 'Stencil', 'Stencil Documentation',
+     author, 'Stencil', 'One line description of project.',
+     'Miscellaneous'),
+]
+
+# Documents to append as an appendix to all manuals.
+#
+# texinfo_appendices = []
+
+# If false, no module index is generated.
+#
+# texinfo_domain_indices = True
+
+# How to display URL addresses: 'footnote', 'no', or 'inline'.
+#
+# texinfo_show_urls = 'footnote'
+
+# If true, do not generate a @detailmenu in the "Top" node's menu.
+#
+# texinfo_no_detailmenu = False

docs/custom-template-tags-and-filters.rst

@@ -0,0 +1,68 @@
+Custom Template Tags and Filters
+================================
+
+You can build your own custom filters and tags and pass them down while
+rendering your template. Any custom filters or tags must be registered with a
+namespace which contains all filters and tags available to the template.
+
+.. code-block:: swift
+
+    let namespace = Namespace()
+    // Register your filters and tags with the namespace
+    let rendered = try template.render(context, namespace: namespace)
+
+Custom Filters
+--------------
+
+Registering custom filters:
+
+.. code-block:: swift
+
+    namespace.registerFilter("double") { (value: Any?) in
+      if let value = value as? Int {
+        return value * 2
+      }
+
+      return value
+    }
+
+Registering custom filters with arguments:
+
+.. code-block:: swift
+
+    namespace.registerFilter("multiply") { (value: Any?, arguments: [Any?]) in
+      let amount: Int
+
+      if let value = arguments.first as? Int {
+        amount = value
+      } else {
+        throw TemplateSyntaxError("multiple tag must be called with an integer argument")
+      }
+
+      if let value = value as? Int {
+        return value * 2
+      }
+
+      return value
+    }
+
+Custom Tags
+-----------
+
+You can build a custom template tag. There are a couple of APIs to allow you to
+write your own custom tags. The following is the simplest form:
+
+.. code-block:: swift
+
+    namespace.registerSimpleTag("custom") { context in
+      return "Hello World"
+    }
+
+When your tag is used via ``{% custom %}`` it will execute the registered block
+of code allowing you to modify or retrieve a value from the context. Then
+return either a string rendered in your template, or throw an error.
+
+If you want to accept arguments or to capture different tokens between two sets
+of template tags. You will need to call the ``registerTag`` API which accepts a
+closure to handle the parsing. You can find examples of the ``now``, ``if`` and
+``for`` tags found inside Stencil source code.

docs/index.rst

@@ -0,0 +1,48 @@
+The Stencil template language
+=============================
+
+Stencil is a simple and powerful template language for Swift. It provides a
+syntax similar to Django and Mustache. If you're familiar with these, you will
+feel right at home with Stencil.
+
+.. code-block:: html+django
+
+    There are {{ articles.count }} articles.
+
+    <ul>
+      {% for article in articles %}
+        <li>{{ article.title }} by {{ article.author }}</li>
+      {% endfor %}
+    </ul>
+
+.. code-block:: swift
+
+   struct Article {
+     let title: String
+     let author: String
+   }
+
+    let context = Context(dictionary: [
+      "articles": [
+        Article(title: "Migrating from OCUnit to XCTest", author: "Kyle Fuller"),
+        Article(title: "Memory Management with ARC", author: "Kyle Fuller"),
+      ]
+    ])
+
+    do {
+      let template = try Template(named: "template.html")
+      let rendered = try template.render(context)
+      print(rendered)
+    } catch {
+      print("Failed to render template \(error)")
+    }
+
+Contents:
+
+.. toctree::
+   :maxdepth: 2
+
+   templates
+   builtins
+   api/context
+   custom-template-tags-and-filters

docs/templates.rst

@@ -0,0 +1,77 @@
+Templates
+=========
+
+- ``{{ ... }}`` for variables to print to the template output
+- ``{% ... %}`` for tags
+- ``{# ... #}`` for comments not included in the template output
+
+Variables
+---------
+
+A variable can be defined in your template using the following:
+
+.. code-block:: html+django
+
+    {{ variable }}
+
+Stencil will look up the variable inside the current variable context and
+evaluate it. When a variable contains a dot, it will try doing the
+following lookup:
+
+- Context lookup
+- Dictionary lookup
+- Array lookup (first, last, count, index)
+- Key value coding lookup
+- Type introspection
+
+For example, if `people` was an array:
+
+.. code-block:: html+django
+
+    There are {{ people.count }} people. {{ people.first }} is the first
+    person, followed by {{ people.1 }}.
+
+Filters
+~~~~~~~
+
+Filters allow you to transform the values of variables. For example, they look like:
+
+.. code-block:: html+django
+
+    {{ variable|uppercase }}
+
+See :ref:`all builtin filters <built-in-filters>`.
+
+Tags
+----
+
+Tags are a mechanism to execute a piece of code, allowing you to have
+control flow within your template.
+
+.. code-block:: html+django
+
+    {% if variable %}
+      {{ variable }} was found.
+    {% endif %}
+
+A tag can also affect the context and define variables as follows:
+
+.. code-block:: html+django
+
+    {% for item in items %}
+      {{ item }}
+    {% endfor %}
+
+Stencil includes of built-in tags which are listed below. You can also
+extend Stencil by providing your own tags.
+
+See :ref:`all builtin tags <built-in-tags>`.
+
+Comments
+--------
+
+To comment out part of your template, you can use the following syntax:
+
+.. code-block:: html+django
+
+    {# My comment is completely hidden #}