Add support for the new function-type syntax.

tests/language/generalized_function_type_test.dart

Index: tests/language/generalized_function_type_test.dart
diff --git a/tests/language/generalized_function_type_test.dart b/tests/language/generalized_function_type_test.dart
new file mode 100644
index 0000000000000000000000000000000000000000..3c6d95099f3c9f0f0449ed1d04b6b7106cf96fab
--- /dev/null
+++ b/tests/language/generalized_function_type_test.dart
@@ -0,0 +1,748 @@
+// 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 'generated_function_syntax_tests.dart';
+
+// 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,
+    [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));
+    } else if (parameterType == null && generateMoreCombinations) {
+      // int Function(int, {x})
+      result.add(new FunctionType(
+          returnType,
+          generics,
+          [new Parameter(new NominalType("int"), null)],
+          null,
+          [new Parameter(null, "x")]));
+      // int Function({x})
+      result.add(new FunctionType(
+          returnType, generics, null, null, [new Parameter(null, "x")]));
+      // int Function(int x, {x})
+      result.add(new FunctionType(
+          returnType,
+          generics,
+          [new Parameter(new NominalType("int"), "y")],
+          null,
+          [new Parameter(null, "x")]));
+      return result;
+    } else {
+      assert(parameterType != null);
+      // int Function(int x).
+      result.add(new FunctionType(
+          returnType, generics, [new Parameter(parameterType, "x")]));
+      if (generateMoreCombinations) {
+        // 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)]));
+      }
+    }
+
+    // Named arguments don't care for parameter types.
+    if (generateMoreCombinations) {
+      // 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;
+}
+
+class Cls {
+  final String name;
+  final StringBuffer tests = new StringBuffer();
+  final StringBuffer fields = new StringBuffer();
+  final StringBuffer boolTests = new StringBuffer();
+  final StringBuffer statics = new StringBuffer();
+  final StringBuffer methods = new StringBuffer();
+
+  Cls(this.name);
+
+  void write(StringBuffer buffer) {
+    buffer.write("""
+class $name<T> {
+  runTests({bool tIsDynamic}) {\n $tests }
+  boolTests() {\n$boolTests}
+  $fields
+  $methods
+}
+    """);
+  }
+}
+
+void generateTests({bool typedefsOnly}) {
+  StringBuffer typedefs = new StringBuffer();
+  StringBuffer typedefOnlyTests = new StringBuffer();
+  StringBuffer statics = new StringBuffer();
+
+  // Keep methods and classes smaller by distributing over several different
+  // classes.
+  List<Cls> classes = [];
+  for (int i = 0; i < 100; i++) {
+    classes.add(new Cls("C$i"));
+  }
+
+  var types = buildFunctionTypes();
+  print("""
+// 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; })();
+
+""");
+  int typeCounter = 0;
+  types.forEach((FunctionType t) {
+    Cls cls = classes[typeCounter % classes.length];
+    /*
+    StringBuffer identifierBuffer = new StringBuffer();
+    t.writeIdentifier(identifierBuffer);
+    String typeName = identifierBuffer.toString();
+    */
+    String typeName = "F$typeCounter";
+
+    StringBuffer typeBuffer = new StringBuffer();
+    t.writeType(typeBuffer);
+    String typeCode = typeBuffer.toString();
+
+    String staticFunName = "f$typeCounter";
+    StringBuffer staticFunBuffer = new StringBuffer();
+    t.writeFunction(staticFunBuffer, staticFunName);
+    String staticFunCode = staticFunBuffer.toString();
+
+    String methodFunName = "m$typeCounter";
+    StringBuffer methodFunBuffer = new StringBuffer();
+    t.writeFunction(methodFunBuffer, methodFunName, replaceT: false);
+    String methodFunCode = methodFunBuffer.toString();
+
+    String fieldName = "_$typeCounter";
+    cls.fields.writeln("  $typeCode $fieldName;");
+
+    String localName = "l$typeCounter";
+
+    typedefs.writeln("typedef $typeName<T> = $typeCode;");
+    statics.writeln(staticFunCode);
+    cls.methods.writeln(methodFunCode);
+
+    // Just make sure that we reference all typedefs in typedefOnly mode.
+    typedefOnlyTests.writeln("  Expect.isFalse(true is $typeName);");
+
+    cls.tests.writeln("  Expect.isTrue($staticFunName is $typeName);");
+    cls.tests.writeln("  Expect.isTrue(confuse($staticFunName) is $typeName);");
+    // In checked mode, verifies the type.
+    cls.tests.writeln("  $fieldName = $staticFunName as dynamic;");
+    cls.tests.writeln("  $typeCode $localName = $staticFunName as dynamic;");
+    cls.tests.writeln("  $fieldName = confuse($staticFunName);");
+    cls.tests.writeln("  $localName = confuse($staticFunName);");
+
+    cls.tests.writeln("  Expect.isTrue($methodFunName is $typeName);");
+    cls.tests.writeln("  Expect.isTrue($methodFunName is $typeCode);");
+    cls.tests.writeln("  Expect.isTrue(confuse($methodFunName) is $typeName);");
+    // In checked mode, verifies the type.
+    cls.tests.writeln("  $fieldName = $methodFunName;");
+    cls.tests.writeln("  $localName = $methodFunName;");
+    cls.tests.writeln("  $fieldName = confuse($methodFunName);");
+    cls.tests.writeln("  $localName = confuse($methodFunName);");
+
+    if (t.usesT) {
+      cls.tests.writeln("  Expect.isTrue($staticFunName is $typeName<int>);");
+      cls.tests.writeln("  Expect.isFalse($staticFunName is $typeName<bool>);");
+      cls.tests.writeln(
+          "  Expect.isTrue(confuse($staticFunName) is $typeName<int>);");
+      cls.tests.writeln(
+          "  Expect.isFalse(confuse($staticFunName) is $typeName<bool>);");
+      cls.tests.writeln(
+          "  Expect.equals(tIsDynamic, $methodFunName is $typeName<bool>);");
+      cls.tests.writeln("  Expect.equals("
+          "tIsDynamic, confuse($methodFunName) is $typeName<bool>);");
+
+
+      cls.boolTests.writeln("  if (inCheckedMode) {");
+      cls.boolTests.writeln(
+          "  Expect.throws(() { $fieldName = ($staticFunName as dynamic); });");
+      cls.boolTests.writeln(
+          "  Expect.throws(() { $fieldName = confuse($staticFunName); });");
+      cls.boolTests.writeln("  Expect.throws("
+          "() { $localName = ($staticFunName as dynamic); });");
+      cls.boolTests.writeln("  Expect.throws("
+          "() { $localName = confuse($staticFunName); });");
+      cls.boolTests.writeln("  }");
+      cls.boolTests.writeln("$typeCode $localName = $methodFunName;");
+
+      // In checked mode, verifies the type.
+      cls.boolTests.writeln("  $fieldName = $methodFunName;");
+      cls.boolTests.writeln("  $fieldName = confuse($methodFunName);");
+    }
+
+    typeCounter++;
+  });
+
+  if (typedefsOnly) {
+    print("""
+$typedefs
+void runTests() {
+$typedefOnlyTests
+}
+""");
+    return;
+  }
+
+  for (var cls in classes) {
+    var buffer = new StringBuffer();
+    cls.write(buffer);
+    print(buffer.toString());
+  }
+  print("""
+$typedefs
+$statics
+
+void runTests() {
+""");
+  for (var cls in classes) {
+    print("""
+ new ${cls.name}().runTests(tIsDynamic: true);
+ new ${cls.name}<int>().runTests(tIsDynamic: false);
+ new ${cls.name}<bool>().boolTests();
+""");
+  }
+  print("} // main");
+}
+
+void printUsage() {
+  print("""
+This program can be run in two modes:
+1. Generating generalized function-type tests.
+2. Running the tests imported from "generated_function_syntax_tests.dart".
+
+It is assumed that the "generated_function_syntax_tests.dart" file is the output
+of a run of this program.
+
+To generate the tests run with either
+* `--generate-typedefs`, or
+* `--generate-all`.
+
+The first generates only tests that use function-type syntax in typedefs.
+The latter generates tests for the same syntax in other locations.
+
+Normally the tests don't need to be regenerated.
+If necessary, a typical workflow would look like follows:
+
+dart generalized_function_type_test.dart --generate-all > generated_function_syntax_tests.dart
+""");
+}
+
+void main(List<String> arguments) {
+  if (arguments.length > 0) {
+    if (arguments.length != 1) {
+      printUsage();
+      return;
+    }
+    if (arguments[0] == "--generate-typedefs") {
+      generateTests(typedefsOnly: true);
+    } else if (arguments[0] == "--generate-all") {
+      generateTests(typedefsOnly: false);
+    } else {
+      printUsage();
+      return;
+    }
+  } else {
+    runTests();
+  }
+}