Introduce context and renderer. This can be considered the first alpha. We are able to render a mustache template now.

Author: lxcid

Diff for: Mustache.xcodeproj/project.pbxproj

@@ -12,9 +12,11 @@
 		AB3B66DA1C2848CA00152024 /* Scanner.swift in Sources */ = {isa = PBXBuildFile; fileRef = AB3B66D71C2848CA00152024 /* Scanner.swift */; };
 		AB5A87571C2A92260095E648 /* Template.swift in Sources */ = {isa = PBXBuildFile; fileRef = AB5A87561C2A92260095E648 /* Template.swift */; };
 		AB5A87591C2A92FB0095E648 /* Operation.swift in Sources */ = {isa = PBXBuildFile; fileRef = AB5A87581C2A92FB0095E648 /* Operation.swift */; };
+		AB5A875B1C2B74310095E648 /* Context.swift in Sources */ = {isa = PBXBuildFile; fileRef = AB5A875A1C2B74310095E648 /* Context.swift */; };
 		AB9DCEBE1C26A8BC00B277FC /* Mustache.h in Headers */ = {isa = PBXBuildFile; fileRef = AB9DCEBD1C26A8BC00B277FC /* Mustache.h */; settings = {ATTRIBUTES = (Public, ); }; };
 		AB9DCEC51C26A8BD00B277FC /* Mustache.framework in Frameworks */ = {isa = PBXBuildFile; fileRef = AB9DCEBA1C26A8BC00B277FC /* Mustache.framework */; };
 		AB9DCECA1C26A8BD00B277FC /* MustacheTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = AB9DCEC91C26A8BD00B277FC /* MustacheTests.swift */; };
+		ABCB02BF1C2BA45F00BED745 /* Renderer.swift in Sources */ = {isa = PBXBuildFile; fileRef = ABCB02BE1C2BA45F00BED745 /* Renderer.swift */; };
 		ABCF38101C29655800B32850 /* Delimiter.swift in Sources */ = {isa = PBXBuildFile; fileRef = ABCF380F1C29655800B32850 /* Delimiter.swift */; };
 		ABCF38121C29659D00B32850 /* Token.swift in Sources */ = {isa = PBXBuildFile; fileRef = ABCF38111C29659D00B32850 /* Token.swift */; };
 		ABCF38141C2967DA00B32850 /* Lookahead.swift in Sources */ = {isa = PBXBuildFile; fileRef = ABCF38131C2967DA00B32850 /* Lookahead.swift */; };
@@ -38,12 +40,14 @@
 		AB3B66D71C2848CA00152024 /* Scanner.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = Scanner.swift; sourceTree = "<group>"; };
 		AB5A87561C2A92260095E648 /* Template.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = Template.swift; sourceTree = "<group>"; };
 		AB5A87581C2A92FB0095E648 /* Operation.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = Operation.swift; sourceTree = "<group>"; };
+		AB5A875A1C2B74310095E648 /* Context.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = Context.swift; sourceTree = "<group>"; };
 		AB9DCEBA1C26A8BC00B277FC /* Mustache.framework */ = {isa = PBXFileReference; explicitFileType = wrapper.framework; includeInIndex = 0; path = Mustache.framework; sourceTree = BUILT_PRODUCTS_DIR; };
 		AB9DCEBD1C26A8BC00B277FC /* Mustache.h */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.h; path = Mustache.h; sourceTree = "<group>"; };
 		AB9DCEBF1C26A8BC00B277FC /* Info.plist */ = {isa = PBXFileReference; lastKnownFileType = text.plist.xml; path = Info.plist; sourceTree = "<group>"; };
 		AB9DCEC41C26A8BD00B277FC /* MustacheTests.xctest */ = {isa = PBXFileReference; explicitFileType = wrapper.cfbundle; includeInIndex = 0; path = MustacheTests.xctest; sourceTree = BUILT_PRODUCTS_DIR; };
 		AB9DCEC91C26A8BD00B277FC /* MustacheTests.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = MustacheTests.swift; sourceTree = "<group>"; };
 		AB9DCECB1C26A8BD00B277FC /* Info.plist */ = {isa = PBXFileReference; lastKnownFileType = text.plist.xml; path = Info.plist; sourceTree = "<group>"; };
+		ABCB02BE1C2BA45F00BED745 /* Renderer.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = Renderer.swift; sourceTree = "<group>"; };
 		ABCF380F1C29655800B32850 /* Delimiter.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = Delimiter.swift; sourceTree = "<group>"; };
 		ABCF38111C29659D00B32850 /* Token.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = Token.swift; sourceTree = "<group>"; };
 		ABCF38131C2967DA00B32850 /* Lookahead.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = Lookahead.swift; sourceTree = "<group>"; };
@@ -83,6 +87,8 @@
 				ABCF38171C29850800B32850 /* Stack.swift */,
 				AB5A87561C2A92260095E648 /* Template.swift */,
 				AB5A87581C2A92FB0095E648 /* Operation.swift */,
+				AB5A875A1C2B74310095E648 /* Context.swift */,
+				ABCB02BE1C2BA45F00BED745 /* Renderer.swift */,
 			);
 			path = Sources;
 			sourceTree = "<group>";
@@ -236,6 +242,8 @@
 				ABCF38121C29659D00B32850 /* Token.swift in Sources */,
 				ABCF38101C29655800B32850 /* Delimiter.swift in Sources */,
 				AB5A87591C2A92FB0095E648 /* Operation.swift in Sources */,
+				ABCB02BF1C2BA45F00BED745 /* Renderer.swift in Sources */,
+				AB5A875B1C2B74310095E648 /* Context.swift in Sources */,
 				AB5A87571C2A92260095E648 /* Template.swift in Sources */,
 				AB3B66DA1C2848CA00152024 /* Scanner.swift in Sources */,
 				ABCF38181C29850800B32850 /* Stack.swift in Sources */,

Diff for: MustacheTests/MustacheTests.swift

@@ -16,7 +16,11 @@ class MustacheTests: XCTestCase {
             let tokens = try lexer.tokenize()
             let parser = Parser(tokens: tokens)
             let mainOperation = try parser.parse()
-            print(mainOperation)
+            let template = try! Template(operation: mainOperation)
+            let context: DictionaryContext = [
+                "name": "Stan"
+            ]
+            print(template.render(context))
         } catch {
             XCTFail()
         }
@@ -28,19 +32,48 @@ class MustacheTests: XCTestCase {
             let tokens = try lexer.tokenize()
             let parser = Parser(tokens: tokens)
             let mainOperation = try parser.parse()
-            print(mainOperation)
+            let template = try! Template(operation: mainOperation)
+            let context: DictionaryContext = [
+                "value": "$5"
+            ]
+            print(template.render(context))
         } catch {
             XCTFail()
         }
     }
 
     func testExample3() {
-        var lexer = Lexer("{{#in_ca}}\nWell, {{taxed_value}} dollars, after taxes.\n{{/in_ca}}")
+        var lexer = Lexer("{{#in_ca}}\nWell, {{taxed_value}} dollars, after taxes.\n{{/in_ca}}{{^in_ca}}\nNo tax burden!\n{{/in_ca}}")
         do {
             let tokens = try lexer.tokenize()
             let parser = Parser(tokens: tokens)
             let mainOperation = try parser.parse()
-            print(mainOperation)
+            let template = try! Template(operation: mainOperation)
+            let context: DictionaryContext = [
+                "in_ca": ArrayContext([
+                    DictionaryContext([
+                        "taxed_value" : "$100"
+                    ]),
+                    DictionaryContext([
+                        "taxed_value" : "$200"
+                    ]),
+                    DictionaryContext([
+                        "taxed_value" : "$300"
+                    ]),
+                    DictionaryContext([
+                        "taxed_value" : "$400"
+                    ]),
+                ])
+            ]
+            print(template.render(context))
+            let context2: DictionaryContext = [
+                "in_ca": DictionaryContext([
+                    "taxed_value" : "$100"
+                ]),
+            ]
+            print(template.render(context2))
+            let context3: DictionaryContext = DictionaryContext(Dictionary<String, Contextual>())
+            print(template.render(context3))
         } catch {
             XCTFail()
         }
@@ -52,7 +85,13 @@ class MustacheTests: XCTestCase {
             let tokens = try lexer.tokenize()
             let parser = Parser(tokens: tokens)
             let mainOperation = try parser.parse()
-            print(mainOperation)
+            let template = try! Template(operation: mainOperation)
+            let context: DictionaryContext = [
+                "name": "Stan",
+                "age": "29",
+                "company": "trifia",
+            ]
+            print(template.render(context))
         } catch {
             XCTFail()
         }

Diff for: Sources/Context.swift

@@ -0,0 +1,94 @@
+//
+//  Context.swift
+//  Mustache
+//
+//  Created by Stan Chang Khin Boon on 24/12/15.
+//  Copyright © 2015 Trifia. All rights reserved.
+//
+
+protocol Contextual : CustomStringConvertible {
+    func contextForName(name: String) -> Contextual?
+    func renderWithOperation(operation: Operation) -> String?
+    func renderWithOperations(operations: [Operation]) -> String?
+}
+
+// MARK: Extensions
+
+// The extension will use the renderer to render instead.
+
+extension String : Contextual {
+    func contextForName(name: String) -> Contextual? {
+        return nil
+    }
+    public var description: String {
+        return self
+    }
+    func renderWithOperation(operation: Operation) -> String? {
+        return Renderer.renderContext(self, withOperation: operation)
+    }
+    func renderWithOperations(operations: [Operation]) -> String? {
+        return Renderer.renderContext(self, withOperations: operations)
+    }
+}
+
+// FIXME: ([email protected]) [Swift 2.1 Limitation, rdar://23196859] Constrainted extension can't inherited protocol
+//extension Dictionary /*: Contextual*/ where Key:Hashable, Value:Contextual {
+//}
+// Workaround for the above limitation…
+struct DictionaryContext : Contextual, DictionaryLiteralConvertible {
+    typealias Key = String
+    typealias Value = Contextual
+    
+    let _value: [Key : Value]
+    init(_ value: [Key : Value]) {
+        self._value = value
+    }
+    init(dictionaryLiteral elements: (Key, Value)...) {
+        // FIXME: ([email protected]) Swift 2.1 limitation…
+        //self._value = Dictionary<Key, Value>(dictionaryLiteral: elements)
+        var dictionary = Dictionary<Key, Value>()
+        for (key, value) in elements {
+            dictionary[key] = value
+        }
+        self.init(dictionary)
+    }
+    func contextForName(name: String) -> Contextual? {
+        return self._value[name]
+    }
+    var description: String {
+        return self._value.description
+    }
+    func renderWithOperation(operation: Operation) -> String? {
+        return Renderer.renderContext(self, withOperation: operation)
+    }
+    func renderWithOperations(operations: [Operation]) -> String? {
+        return Renderer.renderContext(self, withOperations: operations)
+    }
+}
+
+// FIXME: ([email protected]) [Swift 2.1 Limitation, rdar://23196859] Constrainted extension can't inherited protocol
+//extension Array /*: Contextual*/ where Element:Contextual {
+//}
+// Workaround for the above limitation…
+struct ArrayContext : Contextual, ArrayLiteralConvertible {
+    typealias Element = Contextual
+    let _value: Array<Element>
+    init(_ value: Array<Element>) {
+        self._value = value
+    }
+    init(arrayLiteral elements: Element...) {
+        self._value = elements
+    }
+    func contextForName(name: String) -> Contextual? {
+        return nil
+    }
+    var description: String {
+        return self._value.description
+    }
+    func renderWithOperation(operation: Operation) -> String? {
+        return Renderer.renderContexts(self._value, withOperation: operation)
+    }
+    func renderWithOperations(operations: [Operation]) -> String? {
+        return Renderer.renderContexts(self._value, withOperations: operations)
+    }
+}

Diff for: Sources/Parser.swift

@@ -49,14 +49,12 @@ struct Parser {
                 stack.push((scope, operations))
                 (scope, operations) = (Scope.Section(name: name, inverted: inverted), [Operation]())
             case .SectionEnd(let endName):
-                switch scope {
-                case .Section(let name, let inverted) where name == endName:
-                    let section = inverted ? Operation.InvertedSection(name: name, operations: operations) : Operation.Section(name: name, operations: operations)
-                    (scope, operations) = stack.pop()
-                    operations.append(section)
-                default:
+                guard case Scope.Section(let name, let inverted) = scope where name == endName else {
                     throw Error.SyntaxError("Section ended before it began…")
                 }
+                let section = inverted ? Operation.InvertedSection(name: name, operations: operations) : Operation.Section(name: name, operations: operations)
+                (scope, operations) = stack.pop()
+                operations.append(section)
             case .Partial(let name):
                 operations.append(Operation.RenderPartial(name: name))
                 break;
@@ -68,10 +66,10 @@ struct Parser {
                 break
             }
         }
-        switch scope {
-        case .Main:
+        
+        if case Scope.Main = scope {
             return Operation.Main(operations: operations)
-        default:
+        } else {
             throw Error.SyntaxError("Section not closed before file ended…")
         }
     }

Diff for: Sources/Renderer.swift

@@ -0,0 +1,66 @@
+//
+//  Renderer.swift
+//  Mustache
+//
+//  Created by Stan Chang Khin Boon on 24/12/15.
+//  Copyright © 2015 Trifia. All rights reserved.
+//
+
+// Renderer render the operation(s) with the provided context if possible.
+// Otherwise, it give control to the context, which based on its underlying implementation provide some form of control flow. The context might pass back control to renderer to attempt to rendering its subcontext. This resultant in a recursive rendering process.
+struct Renderer {
+    static func renderContext(context: Contextual, withOperation operation: Operation) -> String? {
+        switch operation {
+        case .Main(operations: let operations):
+            return context.renderWithOperations(operations)
+        case .RenderPartial(name: _):
+            // FIXME: ([email protected]) Handle partial
+            return nil
+        case .RenderValue(value: let value):
+            return value
+        case .RenderVariable(name: let name, escaped: _):
+            // FIXME: ([email protected]) Handle escaped
+            return context.contextForName(name)?.description
+        case .Section(name: let name, operations: let operations):
+            guard let newContext = context.contextForName(name) else {
+                return nil
+            }
+            return newContext.renderWithOperations(operations)
+        case .InvertedSection(name: let name, operations: let operations):
+            guard context.contextForName(name) == nil else {
+                return nil
+            }
+            return context.renderWithOperations(operations)
+        }
+    }
+    
+    static func renderContext(context: Contextual, withOperations operations: [Operation]) -> String? {
+        var stringBuffer = ""
+        for operation in operations {
+            if let renderedString = context.renderWithOperation(operation) {
+                stringBuffer.appendContentsOf(renderedString)
+            }
+        }
+        return stringBuffer.isEmpty ? nil : stringBuffer
+    }
+    
+    static func renderContexts(contexts: [Contextual], withOperation operation: Operation) -> String? {
+        var stringBuffer = ""
+        for context in contexts {
+            if let renderedString = renderContext(context, withOperation: operation) {
+                stringBuffer.appendContentsOf(renderedString)
+            }
+        }
+        return stringBuffer.isEmpty ? nil : stringBuffer
+    }
+    
+    static func renderContexts(contexts: [Contextual], withOperations operations: [Operation]) -> String? {
+        var stringBuffer = ""
+        for context in contexts {
+            if let renderedString = renderContext(context, withOperations: operations) {
+                stringBuffer.appendContentsOf(renderedString)
+            }
+        }
+        return stringBuffer.isEmpty ? nil : stringBuffer
+    }
+}

Diff for: Sources/Template.swift

@@ -24,9 +24,14 @@
 struct Template {
     let operation: Operation
 
-    func compile() {
+    init(operation: Operation) throws {
+        guard case Operation.Main(operations: _) = operation else {
+            throw Error.SyntaxError("Template can only hold main operation as it root.")
+        }
+        self.operation = operation
     }
 
-    func render(context: Any) {
+    func render(context: Contextual) -> String? {
+        return context.renderWithOperation(operation)
     }
 }