Adding package:smoke. This CL includes the intial APIs, a mirror-based

pkg/smoke/lib/static.dart

+// Copyright (c) 2014, 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.
+
+/// Static implementation of smoke services using code-generated data.
+library smoke.static;
+
+import 'dart:math' as math;
+
+import 'package:logging/logging.dart';
+import 'package:smoke/smoke.dart';
+
+import 'src/common.dart';
+
+typedef T Getter<T>(object);
+typedef void Setter<T>(object, value);
+
+StaticConfiguration _configuration;
+
+class StaticConfiguration {
+  /// Maps symbol to a function that reads that symbol of an object. For
+  /// instance, `#i: (o) => o.i`.
+  final Map<Symbol, Getter> getters;
+
+  /// Maps symbol to a function that updates that symbol of an object. For
+  /// instance, `#i: (o, v) { o.i = v; }`.
+  final Map<Symbol, Setter> setters;
+
+  /// Maps a type to it's super class. For example, String: Object.
+  final Map<Type, Type> parents;
+
+  /// For each type, a map of declarations per symbol (property or method).
+  final Map<Type, Map<Symbol, Declaration>> declarations;
+
+  /// A map from symbol to strings.
+  final Map<Symbol, String> names;
+
+  /// A map from strings to symbols (the reverse of [names]).
+  final Map<String, Symbol> symbols;
+  StaticConfiguration({
+      this.getters: const {}, this.setters: const {}, this.parents: const {},
+      this.declarations: const {}, this.names: const {}})
+      : this.symbols = {} {
+    names.forEach((k, v) { symbols[v] = k; });
+  }
+}
+
+/// Set up the smoke package to use a static implementation based on the given
+/// [configuration].
+useGeneratedCode(StaticConfiguration configuration) {
+  _configuration = configuration;
+  configure(new _GeneratedObjectAccessorService(),
+      new _GeneratedTypeInspectorService(),
+      new _GeneratedSymbolConverterService());
+}
+
+/// Implements [ObjectAccessorService] using a static configuration.
+class _GeneratedObjectAccessorService implements ObjectAccessorService {
+  read(Object object, Symbol name) {
+    var getter = _configuration.getters[name];
+    if (getter == null) {
+      throw new MissingCodeException('getter "$name" in $object');
+    }
+    return getter(object);
+  }
+  void write(Object object, Symbol name, value) {
+    var setter = _configuration.setters[name];
+    if (setter == null) {
+      throw new MissingCodeException('setter "$name" in $object');
+    }
+    setter(object, value);
+  }
+
+  invoke(object, Symbol name, List args, {Map namedArgs, bool adjust: false}) {
+    var method;
+    if (object is Type) {
+    } else {
+      var getter = _configuration.getters[name];
+      method = getter == null ? null : getter(object);
+    }
+    if (method == null) {
+      throw new MissingCodeException('method "$name" in $object');
+    }
+    var tentativeError;
+    if (adjust) {
+      var min = minArgs(method);
+      if (min > SUPPORTED_ARGS) {
+        tentativeError = 'we tried to adjust the arguments for calling "$name"'
+            ', but we couldn\'t determine the exact number of arguments it '
+            'expects (it is more than $SUPPORTED_ARGS).';
+        // The argument list might be correct, so we still invoke the function
+        // and let the user see the error.
+        args = adjustList(args, min, math.max(min, args.length));
+      } else {
+        var max = maxArgs(method);
+        args = adjustList(args, min, max >= 0 ? max : args.length);
+      }
+    }
+    if (namedArgs != null) {
+      throw new UnsupportedError(
+          'smoke.static doesn\'t support namedArguments in invoke');
+    }
+    try {
+      return Function.apply(method, args);
+    } on NoSuchMethodError catch (e) {
+      // TODO(sigmund): consider whether this should just be in a logger or if
+      // we should wrap `e` as a new exception (what's the best way to let users
+      // know about this tentativeError?)
+      if (tentativeError != null) print(tentativeError);
+      rethrow;
+    }
+  }
+}
+
+/// Implements [TypeInspectorService] using a static configuration.
+class _GeneratedTypeInspectorService implements TypeInspectorService {
+  bool hasGetter(Type type, Symbol name) {
+    var decl = _findDeclaration(type, name);
+    // No need to check decl.isProperty because methods are also automatically
+    // considered getters (auto-closures).
+    return decl != null && !decl.isStatic;
+  }
+
+  bool hasSetter(Type type, Symbol name) {
+    var decl = _findDeclaration(type, name);
+    return decl != null && !decl.isMethod && !decl.isFinal && !decl.isStatic;
+  }
+
+  bool hasInstanceMethod(Type type, Symbol name) {
+    var decl = _findDeclaration(type, name);
+    return decl != null && decl.isMethod && !decl.isStatic;
+  }
+
+  bool hasStaticMethod(Type type, Symbol name) {
+    final map = _configuration.declarations[type];
+    if (map == null) {
+      throw new MissingCodeException('declarations for $type');
+    }
+    final decl = map[name];
+    return decl != null && decl.isMethod && decl.isStatic;
+  }
+
+  Declaration getDeclaration(Type type, Symbol name) {
+    var decl = _findDeclaration(type, name);
+    if (decl == null) {
+      throw new MissingCodeException('declaration for $type.$name');
+    }
+    return decl;
+  }
+
+  List<Declaration> query(Type type, QueryOptions options) {
+    var result;
+    if (options.includeInherited) {
+      var superclass = _configuration.parents[type];
+      if (superclass == null) {
+        throw new MissingCodeException('superclass of "$type"');
+      }
+      result = (superclass == Object) ? [] : query(superclass, options);
+    } else {
+      result = [];
+    }
+    var map = _configuration.declarations[type];
+    if (map == null) {
+      throw new MissingCodeException('declarations for $type');
+    }
+    for (var decl in map.values) {
+      if (!options.includeProperties && decl.isProperty) continue;
+      if (options.excludeFinal && decl.isFinal) continue;
+      if (!options.includeMethods && decl.isMethod) continue;
+      if (options.withAnnotations != null &&
+          !matchesAnnotation(decl.annotations, options.withAnnotations)) {
+        continue;
+      }
+      result.add(decl);
+    }
+    return result;
+  }
+}
+
+/// Implements [SymbolConverterService] using a static configuration.
+class _GeneratedSymbolConverterService implements SymbolConverterService {
+  String symbolToName(Symbol symbol) => _configuration.names[symbol];
+  Symbol nameToSymbol(String name) => _configuration.symbols[name];
+}
+
+
+/// Exception thrown when trynig to access something that should be there, but
+/// the code generator didn't include it.
+class MissingCodeException implements Exception {
+  final String description;
+  MissingCodeException(this.description);
+
+  String toString() => 'Missing $description. '
+      'Code generation for the smoke package seems incomplete.';
+}
+
+Declaration _findDeclaration(Type type, Symbol name) {
+  while (type != Object) {
+    final declarations = _configuration.declarations[type];
+    if (declarations != null) {
+      final declaration = declarations[name];
+      if (declaration != null) return declaration;
+    }
+    var parentType = _configuration.parents[type];
+    if (parentType == null) {
+      throw new MissingCodeException('superclass of "$type"');
+    }
+    type = parentType;
+  }
+  return null;
+}