Add support for the new function-type syntax.

tests/language/function_type/test_generator.dart

Index: tests/language/function_type/test_generator.dart
diff --git a/tests/language/function_type/test_generator.dart b/tests/language/function_type/test_generator.dart
new file mode 100644
index 0000000000000000000000000000000000000000..86d679496b7275d4d79fcd171461ed94f4c2f9d6
--- /dev/null
+++ b/tests/language/function_type/test_generator.dart
@@ -0,0 +1,755 @@
+// Copyright (c) 2016, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+import 'dart:io';
+
+// By convention:
+//
+//   T: generic type of typedef.
+//   A: generic type of returned function.
+//   B: generic type of function.
+//
+// Example:
+//    typedef F<T>: Function<A> Function<B>();
+//
+// We only use: Function, List, int (and function types).
+// We import 'dart:core' directly and with prefix 'core'.
+
+abstract class Printable {
+  /// Builds a descriptive string that can be used as an identifier.
+  ///
+  /// The string is mainly used for disambiguation, and not for its readability.
+  void writeIdentifier(StringBuffer buffer);
+}
+
+abstract class TypeLike implements Printable {
+  /// Prints `this` as valid Dart code for a Type.
+  void writeType(StringBuffer buffer);
+
+  /// Whether this instance uses T in some way.
+  bool get usesT;
+}
+
+/// Provides a unique integer for every parameter in a function.
+int parameterNameCounter = 0;
+
+/// Whether `T` should be replaced with `int`.
+bool shouldReplaceTWithInt = false;
+
+class Parameter implements Printable {
+  final TypeLike type;
+  final String name;
+
+  Parameter(this.type, this.name);
+
+  // Type or name can be null.
+  @override
+  writeIdentifier(buffer) {
+    if (type == null) {
+      buffer.write("null");
+    } else {
+      type.writeIdentifier(buffer);
+    }
+    buffer.write("_");
+    buffer.write(name);
+  }
+
+  void writeType(StringBuffer buffer) {
+    assert(type != null || name != null);
+    if (name == null) {
+      type.writeType(buffer);
+    } else if (type == null) {
+      buffer.write(name);
+    } else {
+      type.writeType(buffer);
+      buffer.write(" ");
+      buffer.write(name);
+    }
+  }
+
+  void writeInFunction(StringBuffer buffer) {
+    assert(type != null || name != null);
+    if (name == null) {
+      type.writeType(buffer);
+      buffer.write(" x");
+      buffer.write(parameterNameCounter++);
+    } else if (type == null) {
+      buffer.write(name);
+    } else {
+      type.writeType(buffer);
+      buffer.write(" ");
+      buffer.write(name);
+    }
+  }
+
+  bool operator ==(other) {
+    return other is Parameter && name == other.name && type == other.type;
+  }
+
+  int get hashCode {
+    return ((name.hashCode * 37) ^ type.hashCode) & 0xFFFFFFFF;
+  }
+
+  bool get usesT => type?.usesT == true;
+}
+
+class GenericParameter implements TypeLike {
+  final String name;
+  final TypeLike bound;
+
+  GenericParameter(this.name, [this.bound]);
+
+  // Bound may be null.
+  @override
+  writeIdentifier(buffer) {
+    buffer.write(name);
+    buffer.write("_");
+    if (bound == null) {
+      buffer.write("null");
+    } else {
+      bound.writeIdentifier(buffer);
+    }
+  }
+
+  @override
+  writeType(buffer) {
+    buffer.write(name);
+    if (bound != null) {
+      buffer.write(" extends ");
+      bound.writeType(buffer);
+    }
+  }
+
+  bool operator ==(other) {
+    return other is GenericParameter &&
+        name == other.name &&
+        bound == other.bound;
+  }
+
+  int get hashCode {
+    return ((name.hashCode * 23) ^ bound.hashCode) & 0xFFFFFFFF;
+  }
+
+  bool get usesT {
+    return bound?.usesT == true;
+  }
+}
+
+void _describeList(StringBuffer buffer, List<Printable> list) {
+  if (list == null) {
+    buffer.write("0");
+    return;
+  }
+  buffer.write(list.length.toString());
+  buffer.write("_");
+  for (int i = 0; i < list.length; i++) {
+    if (i != 0) buffer.write("_");
+    list[i].writeIdentifier(buffer);
+  }
+}
+
+void _writeTypes(StringBuffer buffer, List<TypeLike> list,
+    [String prefix = "", String postfix = ""]) {
+  if (list == null || list.isEmpty) return;
+  buffer.write(prefix);
+  for (int i = 0; i < list.length; i++) {
+    if (i != 0) buffer.write(", ");
+    list[i].writeType(buffer);
+  }
+  buffer.write(postfix);
+}
+
+void _writeParameters(
+    StringBuffer buffer, List<Parameter> list, bool inFunction,
+    [String prefix = "", String postfix = ""]) {
+  if (list == null || list.isEmpty) return;
+  buffer.write(prefix);
+  for (int i = 0; i < list.length; i++) {
+    if (i != 0) buffer.write(", ");
+    if (inFunction) {
+      list[i].writeInFunction(buffer);
+    } else {
+      list[i].writeType(buffer);
+    }
+  }
+  buffer.write(postfix);
+}
+
+bool _listUsesT(List elements) {
+  if (elements == null) return false;
+  return elements.any((p) => p.usesT);
+}
+
+bool _listEquals(List list1, List list2) {
+  if (list1 == list2) return true; // Also covers both being null.
+  if (list1 == null || list2 == null) return false;
+  for (int i = 0; i < list1.length; i++) {
+    if (list1[i] != list2[i]) return false;
+  }
+  return true;
+}
+
+int _listHash(List list) {
+  if (list == null) return null.hashCode;
+  int result = 71;
+  for (int i = 0; i < list.length; i++) {
+    result = ((result * 11) ^ list[i].hashCode) & 0xFFFFFFFF;
+  }
+  return result;
+}
+
+class FunctionType implements TypeLike {
+  final TypeLike returnType;
+  final List<GenericParameter> generic;
+  final List<Parameter> required;
+  final List<Parameter> optional;
+  final List<Parameter> named;
+
+  FunctionType(this.returnType, this.generic, this.required,
+      [this.optional, this.named]);
+
+  @override
+  writeIdentifier(buffer) {
+    buffer.write("Fun_");
+    if (returnType == null) {
+      buffer.write("null");
+    } else {
+      returnType.writeIdentifier(buffer);
+    }
+    buffer.write("_");
+    _describeList(buffer, generic);
+    buffer.write("_");
+    _describeList(buffer, required);
+    buffer.write("_");
+    _describeList(buffer, optional);
+    buffer.write("_");
+    _describeList(buffer, named);
+  }
+
+  @override
+  writeType(buffer) {
+    if (returnType != null) {
+      returnType.writeType(buffer);
+      buffer.write(" ");
+    }
+    buffer.write("Function");
+    if (generic != null) _writeTypes(buffer, generic, "<", ">");
+    buffer.write("(");
+    bool notInFunction = true;
+    _writeParameters(buffer, required, notInFunction);
+    if ((optional != null || named != null) &&
+        required != null &&
+        required.isNotEmpty) {
+      buffer.write(", ");
+    }
+    _writeParameters(buffer, optional, notInFunction, "[", "]");
+    _writeParameters(buffer, named, notInFunction, "{", "}");
+    buffer.write(")");
+  }
+
+  /// Writes this type as if it was a function.
+  void writeFunction(StringBuffer buffer, String name, {bool replaceT: true}) {
+    shouldReplaceTWithInt = replaceT;
+    parameterNameCounter = 0;
+
+    if (returnType != null) {
+      returnType.writeType(buffer);
+      buffer.write(" ");
+    }
+
+    buffer.write(name);
+    if (generic != null) _writeTypes(buffer, generic, "<", ">");
+    buffer.write("(");
+    bool inFunction = true;
+    _writeParameters(buffer, required, inFunction);
+    if ((optional != null || named != null) &&
+        required != null &&
+        required.isNotEmpty) {
+      buffer.write(", ");
+    }
+    _writeParameters(buffer, optional, inFunction, "[", "]");
+    _writeParameters(buffer, named, inFunction, "{", "}");
+    buffer.write(") => null;");
+
+    shouldReplaceTWithInt = false;
+  }
+
+  bool operator ==(other) {
+    return returnType == other.returnType &&
+        _listEquals(generic, other.generic) &&
+        _listEquals(required, other.required) &&
+        _listEquals(optional, other.optional) &&
+        _listEquals(named, other.named);
+  }
+
+  int get hashCode {
+    return ((returnType.hashCode * 13) ^
+            (_listHash(generic) * 17) ^
+            (_listHash(required) * 53) ^
+            (_listHash(optional) ^ 31) ^
+            (_listHash(named) * 87)) &
+        0xFFFFFFFF;
+  }
+
+  bool get usesT {
+    return returnType?.usesT == true ||
+        [generic, required, optional, named].any(_listUsesT);
+  }
+}
+
+class NominalType implements TypeLike {
+  final String prefix;
+  final String name;
+  final List<TypeLike> generic;
+
+  NominalType(this.name, [this.prefix, this.generic]);
+
+  @override
+  writeIdentifier(buffer) {
+    buffer.write(prefix);
+    buffer.write("_");
+    buffer.write(name);
+    _describeList(buffer, generic);
+  }
+
+  @override
+  writeType(buffer) {
+    if (prefix != null && prefix != "") {
+      buffer.write(prefix);
+      buffer.write(".");
+    }
+    if (shouldReplaceTWithInt && name == "T") {
+      buffer.write("int");
+    } else {
+      buffer.write(name);
+    }
+    _writeTypes(buffer, generic, "<", ">");
+  }
+
+  bool operator ==(other) {
+    return other is NominalType && prefix == other.prefix && name == other.name;
+  }
+
+  int get hashCode {
+    return ((prefix.hashCode * 37) ^ name.hashCode) & 0xFFFFFFFF;
+  }
+
+  bool get usesT => name == "T" || _listUsesT(generic);
+}
+
+List<FunctionType> buildFunctionTypes() {
+  List<GenericParameter> as = [
+    new GenericParameter("A"),
+    // new GenericParameter("A", new NominalType("int")),
+    // new GenericParameter("A", new NominalType("int", "core")),
+  ];
+  List<GenericParameter> bs = [
+    // new GenericParameter("B"),
+    // new GenericParameter("B", new NominalType("int")),
+    new GenericParameter("B", new NominalType("int", "core")),
+  ];
+  List<TypeLike> basicTypes = [
+    new NominalType("int"),
+    // new NominalType("int", "core"),
+    // new NominalType("List"),
+    // new NominalType("List", "core"),
+    new NominalType("Function"),
+    new NominalType("List", "", [new NominalType("Function")]),
+    new NominalType("List", "core", [new NominalType("int", "core")]),
+    new NominalType("List", "", [new NominalType("T")]),
+    // new NominalType("List", "", [new NominalType("Function")]),
+  ];
+
+  List<TypeLike> basicsPlusNull = [
+    basicTypes,
+    <TypeLike>[null]
+  ].expand((x) => x).toList();
+
+  List<TypeLike> basicsPlusNullPlusB = [
+    basicsPlusNull,
+    [
+      new NominalType("B"),
+      new NominalType("List", "", [new NominalType("B")])
+    ]
+  ].expand((x) => x).toList();
+
+  List<TypeLike> basicsPlusNullPlusA = [
+    basicsPlusNull,
+    [
+      new NominalType("A"),
+      new NominalType("List", "", [new NominalType("A")])
+    ]
+  ].expand((x) => x).toList();
+
+  List<TypeLike> buildFunctionTypes(TypeLike returnType, TypeLike parameterType,
+      [List<GenericParameter> generics,
+      bool generateMoreCombinations = false]) {
+    List<TypeLike> result = [];
+
+    if (parameterType == null) {
+      // int Function().
+      result.add(new FunctionType(returnType, generics, null));
+      return result;
+    }
+
+    // int Function(int x).
+    result.add(new FunctionType(
+        returnType, generics, [new Parameter(parameterType, "x")]));
+
+    if (!generateMoreCombinations) return result;
+
+    // int Function([int x]).
+    result.add(new FunctionType(
+        returnType, generics, null, [new Parameter(parameterType, "x")]));
+    // int Function(int, [int x])
+    result.add(new FunctionType(
+        returnType,
+        generics,
+        [new Parameter(new NominalType("int"), null)],
+        [new Parameter(parameterType, "x")]));
+    // int Function(int x, [int x])
+    result.add(new FunctionType(
+        returnType,
+        generics,
+        [new Parameter(new NominalType("int"), "y")],
+        [new Parameter(parameterType, "x")]));
+    // int Function(int);
+    result.add(new FunctionType(
+        returnType, generics, [new Parameter(parameterType, null)]));
+    // int Function([int]);
+    result.add(new FunctionType(
+        returnType, generics, null, [new Parameter(parameterType, null)]));
+    // int Function(int, [int])
+    result.add(new FunctionType(
+        returnType,
+        generics,
+        [new Parameter(new NominalType("int"), null)],
+        [new Parameter(parameterType, null)]));
+    // int Function(int x, [int])
+    result.add(new FunctionType(
+        returnType,
+        generics,
+        [new Parameter(new NominalType("int"), "x")],
+        [new Parameter(parameterType, null)]));
+    // int Function({int x}).
+    result.add(new FunctionType(returnType, generics, null, null,
+        [new Parameter(parameterType, "x")]));
+    // int Function(int, {int x})
+    result.add(new FunctionType(
+        returnType,
+        generics,
+        [new Parameter(new NominalType("int"), null)],
+        null,
+        [new Parameter(parameterType, "x")]));
+    // int Function(int x, {int x})
+    result.add(new FunctionType(
+        returnType,
+        generics,
+        [new Parameter(new NominalType("int"), "y")],
+        null,
+        [new Parameter(parameterType, "x")]));
+    return result;
+  }
+
+  // The "smaller" function types. May also be used non-nested.
+  List<TypeLike> functionTypes = [];
+
+  for (TypeLike returnType in basicsPlusNull) {
+    for (TypeLike parameterType in basicsPlusNull) {
+      bool generateMoreCombinations = true;
+      functionTypes.addAll(buildFunctionTypes(
+          returnType, parameterType, null, generateMoreCombinations));
+    }
+  }
+
+  // These use `B` from the generic type of the enclosing function.
+  List<TypeLike> returnFunctionTypesB = [];
+  for (TypeLike returnType in basicsPlusNullPlusB) {
+    TypeLike parameterType = new NominalType("B");
+    returnFunctionTypesB.addAll(buildFunctionTypes(returnType, parameterType));
+  }
+  for (TypeLike parameterType in basicsPlusNull) {
+    TypeLike returnType = new NominalType("B");
+    returnFunctionTypesB.addAll(buildFunctionTypes(returnType, parameterType));
+  }
+
+  for (TypeLike returnType in basicsPlusNullPlusA) {
+    for (TypeLike parameterType in basicsPlusNullPlusA) {
+      for (GenericParameter a in as) {
+        functionTypes
+            .addAll(buildFunctionTypes(returnType, parameterType, [a]));
+      }
+    }
+  }
+
+  List<TypeLike> types = [];
+  types.addAll(functionTypes);
+
+  // Now add some higher-order function types.
+  for (TypeLike returnType in functionTypes) {
+    types.addAll(buildFunctionTypes(returnType, null));
+    types.addAll(buildFunctionTypes(returnType, new NominalType("int")));
+    for (var b in bs) {
+      types.addAll(buildFunctionTypes(returnType, null, [b]));
+      types.addAll(buildFunctionTypes(returnType, new NominalType("int"), [b]));
+    }
+  }
+  for (TypeLike returnType in returnFunctionTypesB) {
+    for (var b in bs) {
+      types.addAll(buildFunctionTypes(returnType, null, [b]));
+      types.addAll(buildFunctionTypes(returnType, new NominalType("int"), [b]));
+    }
+  }
+
+  return types;
+}
+
+final String HEADER = """
+// Copyright (c) 2016, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+// GENERATED - DON'T EDIT.
+// GENERATED - DON'T EDIT.
+// GENERATED - DON'T EDIT.
+// GENERATED - DON'T EDIT.
+// GENERATED - DON'T EDIT.
+// GENERATED - DON'T EDIT.
+// GENERATED - DON'T EDIT.
+// GENERATED - DON'T EDIT.
+
+import 'dart:core';
+import 'dart:core' as core;
+import 'package:expect/expect.dart';
+
+@NoInline()
+@AssumeDynamic()
+confuse(f) => f;
+
+final bool inCheckedMode =
+    (() { bool result = false; assert(result = true); return result; })();
+""";
+
+
+class Unit {
+  final String name;
+  final StringBuffer typedefs = new StringBuffer();
+  final StringBuffer globals = new StringBuffer();
+  final StringBuffer tests = new StringBuffer();
+  final StringBuffer fields = new StringBuffer();
+  final StringBuffer statics = new StringBuffer();
+  final StringBuffer testMethods = new StringBuffer();
+  final StringBuffer methods = new StringBuffer();
+
+  Unit(this.name);
+
+  void write(StringBuffer buffer) {
+    buffer.write("""
+$HEADER
+
+$typedefs
+
+$globals
+
+class $name<T> {
+  final bool tIsBool;
+  final bool tIsInt;
+  final bool tIsDynamic;
+
+$fields
+
+  $name({this.tIsBool: false, this.tIsInt: false})
+      : tIsDynamic = !tIsBool && !tIsInt;
+
+$methods
+
+  runTests() {\n$tests  }
+
+$testMethods
+}
+
+void main() {
+  new $name().runTests();
+  new $name<int>(tIsInt: true).runTests();
+  new $name<bool>(tIsBool: true).runTests();
+}
+    """);
+  }
+}
+
+
+final TEST_METHOD_HEADER = """
+  void #testName() {
+    // #typeCode""";
+
+// Tests that apply for every type.
+final COMMON_TESTS_TEMPLATE = """
+    Expect.isTrue(#staticFunName is #typeName);
+    Expect.isTrue(confuse(#staticFunName) is #typeName);
+    // In checked mode, verifies the type.
+    #typeCode #localName;
+    // The static function #staticFunName sets `T` to `int`.
+    if (!tIsBool) {
+      #fieldName = #staticFunName as dynamic;
+      #localName = #staticFunName as dynamic;
+      #fieldName = confuse(#staticFunName);
+      #localName = confuse(#staticFunName);
+    }
+
+    Expect.isTrue(#methodFunName is #typeName);
+    Expect.isTrue(#methodFunName is #typeCode);
+    Expect.isTrue(confuse(#methodFunName) is #typeName);
+    // In checked mode, verifies the type.
+    #fieldName = #methodFunName;
+    #localName = #methodFunName;
+    #fieldName = confuse(#methodFunName);
+    #localName = confuse(#methodFunName);""";
+
+// Tests that depend on the typedef "T" argument.
+//
+// These tests are executed when the surrounding class is instantiated with
+// its generic type set to `int`, `dynamic` or `bool`. In the latter case, the
+// class field `tIsBool` is set to true.
+
+// While the types themselves are not affected by the class` `T`, the methods
+// of the class may use `T`:
+//
+// For example:
+//   class A<T> {
+//      f(List<T> x) {}
+//   }
+final TYPEDEF_T_TESTS_TEMPLATE = """
+    if (!tIsBool) {
+      Expect.isTrue(#staticFunName is #typeName<int>);
+      Expect.isFalse(#staticFunName is #typeName<bool>);
+      Expect.isTrue(confuse(#staticFunName) is #typeName<int>);
+      Expect.isFalse(confuse(#staticFunName) is #typeName<bool>);
+      Expect.equals(tIsDynamic, #methodFunName is #typeName<bool>);
+      Expect.equals(tIsDynamic, confuse(#methodFunName) is #typeName<bool>);
+    } else {
+      if (inCheckedMode) {
+        Expect.throws(() { #fieldName = (#staticFunName as dynamic); });
+        Expect.throws(() { #fieldName = confuse(#staticFunName); });
+        #typeCode #localName;
+        Expect.throws(() { #localName = (#staticFunName as dynamic); });
+        Expect.throws(() { #localName = confuse(#staticFunName); });
+      }
+      #typeCode #localName = #methodFunName;
+      // In checked mode, verifies the type.
+      #fieldName = #methodFunName;
+      #fieldName = confuse(#methodFunName);
+    }""";
+
+final TEST_METHOD_FOOTER = "  }";
+
+String createTypeName(int id) => "F$id";
+String createStaticFunName(int id) => "f$id";
+String createMethodFunName(int id) => "m$id";
+String createFieldName(int id) => "x$id";
+String createLocalName(int id) => "l$id";
+String createTestName(int id) => "test${createTypeName(id)}";
+
+String createTypeCode(FunctionType type) {
+  StringBuffer typeBuffer = new StringBuffer();
+  type.writeType(typeBuffer);
+  return typeBuffer.toString();
+}
+String createStaticFunCode(FunctionType type, int id) {
+  StringBuffer staticFunBuffer = new StringBuffer();
+  type.writeFunction(staticFunBuffer, createStaticFunName(id));
+  return staticFunBuffer.toString();
+}
+
+String createMethodFunCode(FunctionType type, int id) {
+  StringBuffer methodFunBuffer = new StringBuffer();
+  type.writeFunction(methodFunBuffer, createMethodFunName(id), replaceT: false);
+  return methodFunBuffer.toString();
+}
+
+String createTestMethodFunCode(FunctionType type, String typeCode, int id) {
+  String fillTemplate(String template, int id) {
+    var result = template
+        .replaceAll("#typeName", createTypeName(id))
+        .replaceAll("#staticFunName", createStaticFunName(id))
+        .replaceAll("#methodFunName", createMethodFunName(id))
+        .replaceAll("#fieldName", createFieldName(id))
+        .replaceAll("#localName", createLocalName(id))
+        .replaceAll("#testName", createTestName(id))
+        .replaceAll("#typeCode", typeCode);
+    assert(!result.contains("#"));
+    return result;
+  }
+
+  String commonTests = fillTemplate(COMMON_TESTS_TEMPLATE, id);
+  String genericTTests = "";
+  if (type.usesT) {
+    genericTTests = fillTemplate(TYPEDEF_T_TESTS_TEMPLATE, id);
+  }
+  return """
+${fillTemplate(TEST_METHOD_HEADER, id)}
+$commonTests
+$genericTTests
+$TEST_METHOD_FOOTER
+""";
+}
+
+void generateTests() {
+  // Keep methods and classes smaller by distributing over several different
+  // classes.
+  List<Unit> units = [];
+  for (int i = 0; i < 100; i++) {
+    units.add(new Unit("U$i"));
+  }
+
+  var types = buildFunctionTypes();
+
+  int typeCounter = 0;
+  types.forEach((FunctionType type) {
+    Unit unit = units[typeCounter % units.length];
+
+    String typeName = createTypeName(typeCounter);
+    String fieldName = createFieldName(typeCounter);
+    String testName = createTestName(typeCounter);
+
+    String typeCode = createTypeCode(type);
+    String staticFunCode = createStaticFunCode(type, typeCounter);
+    String methodFunCode = createMethodFunCode(type, typeCounter);
+    String testMethodCode =
+        createTestMethodFunCode(type, typeCode, typeCounter);
+
+
+    unit.typedefs.writeln("typedef $typeName<T> = $typeCode;");
+    unit.globals.writeln(staticFunCode);
+    unit.fields.writeln("  $typeCode $fieldName;");
+    unit.methods.writeln("  $methodFunCode");
+    unit.testMethods.writeln("$testMethodCode");
+    unit.tests.writeln("    $testName();");
+
+    typeCounter++;
+  });
+
+  for (int i = 0; i < units.length; i++) {
+    var unit = units[i];
+    var buffer = new StringBuffer();
+    unit.write(buffer);
+    var path = Platform.script.resolve("function_type${i}_test.dart").path;
+    new File(path).writeAsStringSync(buffer.toString());
+  }
+}
+
+void printUsage() {
+  print("""
+Generates function type tests.
+
+All tests are generated in the same directory as this script.
+""");
+}
+
+void main(List<String> arguments) {
+  if (arguments.length != 0) {
+    printUsage();
+    return;
+  }
+  generateTests();
+}