Lots of frog cleanup

frog/member_set.dart

+// Copyright (c) 2012, 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.
+
+class MemberSet {
+  final String name;
+  final List<Member> members;
+  final String jsname;
+  final bool isVar;
+
+  bool _treatAsField;
+  Type _returnTypeForGet;
+  bool _preparedForSet = false;
+  List<InvokeKey> _invokes;
+
+  MemberSet(Member member, [bool isVar=false]):
+    name = member.name, members = [member], jsname = member.jsname,
+    isVar = isVar;
+
+  toString() => '$name:${members.length}';
+
+  void add(Member member) {
+    // Only methods on classes "really exist" - so warn if we add others?
+    members.add(member);
+  }
+
+  // TODO(jimhug): Better way to check for operator.
+  bool get isOperator() => members[0].isOperator;
+
+  Value _makeError(Node node, Value target, String action) {
+    if (!target.type.isVar) {
+      world.warning('could not find applicable $action for "$name"', node.span);
+    }
+    return new Value(world.varType,
+        '${target.code}.$jsname() /*no applicable $action*/', node.span);
+  }
+
+  bool get treatAsField() {
+    if (_treatAsField == null) {
+      _treatAsField = !isVar && members.every((m) => m.isField);
+    }
+    return _treatAsField;
+  }
+
+  static Type unionTypes(Type t1, Type t2) {
+    if (t1 == null) return t2;
+    if (t2 == null) return t1;
+    return Type.union(t1, t2);
+  }
+
+  /**
+   * This needs to generate one of the following:
+   * - target.name
+   * - target.get$name()
+   * - target.noSuchMethod(...)
+   *
+   * Can be treated as a field only if this is a properly resolved reference
+   * and all resolve members are fields.
+   */
+  Value _get(CallingContext context, Node node, Value target) {
+    if (members.length == 1 && !isVar) {
+      return members[0]._get(context, node, target);
+    }
+
+    if (_returnTypeForGet == null) {
+      for (var member in members) {
+        if (!member.canGet) continue;
+        if (!treatAsField) member.providePropertySyntax();
+        // TODO(jimhug): Need to make target less specific...
+        var r = member._get(context, node, target);
+        _returnTypeForGet = unionTypes(_returnTypeForGet, r.type);
+      }
+      if (_returnTypeForGet == null) {
+        world.error('no valid getters for "$name"', node.span);
+      }
+    }
+
+    if (_treatAsField) {
+      return new Value(_returnTypeForGet, '${target.code}.$jsname',
+        node.span);
+    } else {
+      return new Value(_returnTypeForGet, '${target.code}.get\$$jsname()',
+          node.span);
+    }
+  }
+
+  // TODO(jimhug): Return value of this method is unclear.
+  Value _set(CallingContext context, Node node, Value target, Value value) {
+    // If this is the global MemberSet from world, always bind dynamically.
+    // Note: we need this for proper noSuchMethod and REPL behavior.
+    if (members.length == 1 && !isVar) {
+      return members[0]._set(context, node, target, value);
+    }
+
+    if (!_preparedForSet) {
+      _preparedForSet = true;
+
+      for (var member in members) {
+        if (!member.canSet) continue;
+        if (!treatAsField) member.providePropertySyntax();
+        // !!! Need more generic args to this call below.
+        var r = member._set(context, node, target, value);
+      }
+    }
+
+    if (treatAsField) {
+      return new Value(value.type,
+        '${target.code}.$jsname = ${value.code}', node.span);
+    } else {
+      return new Value(value.type,
+        '${target.code}.set\$$jsname(${value.code})', node.span);
+    }
+  }
+
+  Value invoke(CallingContext context, Node node, Value target,
+      Arguments args) {
+    if (members.length == 1 && !isVar) {
+      return members[0].invoke(context, node, target, args);
+    }
+
+    var invokeKey = null;
+    if (_invokes == null) {
+      _invokes = [];
+      invokeKey = null;
+    } else {
+      for (var ik in _invokes) {
+        if (ik.matches(args)) {
+          invokeKey = ik;
+          break;
+        }
+      }
+    }
+    if (invokeKey == null) {
+      invokeKey = new InvokeKey(args);
+      _invokes.add(invokeKey);
+      invokeKey.addMembers(members, context, target, args);
+    }
+
+    // TODO(jimhug): isOperator test is too lenient - misses opt chances
+    if (invokeKey.needsVarCall || isOperator) {
+      if (name == ':call') {
+        return target._varCall(context, node, args);
+      } else if (isOperator) {
+        // TODO(jmesserly): make operators less special.
+        return invokeSpecial(target, args, invokeKey.returnType);
+      } else {
+        return invokeOnVar(context, node, target, args);
+      }
+    } else {
+      var code = '${target.code}.${jsname}(${args.getCode()})';
+      return new Value(invokeKey.returnType, code, node.span);
+    }
+  }
+
+  Value invokeSpecial(Value target, Arguments args, Type returnType) {
+    assert(name.startsWith(':'));
+    assert(!args.hasNames);
+    // TODO(jimhug): We need to do this a little bit more like get and set on
+    // properties.  We should check the set of members for something
+    // like "requiresNativeIndexer" and "requiresDartIndexer" to
+    // decide on a strategy.
+
+    var argsString = args.getCode();
+    // Most operator calls need to be emitted as function calls, so we don't
+    // box numbers accidentally. Indexing is the exception.
+    if (name == ':index' || name == ':setindex') {
+      // TODO(jimhug): should not need this test both here and in invoke
+      if (name == ':index') {
+        world.gen.corejs.useIndex = true;
+      } else if (name == ':setindex') {
+        world.gen.corejs.useSetIndex = true;
+      }
+      return new Value(returnType, '${target.code}.$jsname($argsString)',
+          target.span);
+    } else {
+      if (argsString.length > 0) argsString = ', $argsString';
+      world.gen.corejs.useOperator(name);
+      return new Value(returnType, '$jsname(${target.code}$argsString)',
+          target.span);
+    }
+  }
+
+  Value invokeOnVar(CallingContext context, Node node, Value target,
+      Arguments args) {
+    context.counters.dynamicMethodCalls++;
+
+    var member = getVarMember(context, node, args);
+    return member.invoke(context, node, target, args);
+  }
+
+  dumpAllMembers() {
+    for (var member in members) {
+      world.warning('hard-multi $name on ${member.declaringType.name}',
+          member.span);
+    }
+  }
+
+  VarMember getVarMember(CallingContext context, Node node, Arguments args) {
+    if (world.objectType.varStubs == null) {
+      world.objectType.varStubs = {};
+    }
+
+    var stubName = _getCallStubName(name, args);
+    var stub = world.objectType.varStubs[stubName];
+    if (stub == null) {
+      // Ensure that we're making stub with all possible members of this name.
+      // We need this canonicalization step because only one VarMemberSet can
+      // live on Object.prototype
+      // TODO(jmesserly): this is ugly--we're throwing away type information!
+      // The right solution is twofold:
+      //   1. put stubs on a more precise type when possible
+      //   2. merge VarMemberSets together if necessary
+      final mset = context.findMembers(name).members;
+
+      final targets = mset.filter((m) => m.canInvoke(context, args));
+      stub = new VarMethodSet(name, stubName, targets, args,
+          _foldTypes(targets));
+      world.objectType.varStubs[stubName] = stub;
+    }
+    return stub;
+  }
+
+  Type _foldTypes(List<Member> targets) =>
+    reduce(map(targets, (t) => t.returnType), Type.union, world.varType);
+}
+
+
+class InvokeKey {
+  int bareArgs;
+  List<String> namedArgs;
+  Type returnType;
+  bool needsVarCall = false;
+
+  InvokeKey(Arguments args) {
+    bareArgs = args.bareCount;
+    if (bareArgs != args.length) {
+      namedArgs = args.getNames();
+    }
+  }
+
+  bool matches(Arguments args) {
+    if (namedArgs == null) {
+      if (bareArgs != args.length) return false;
+    } else {
+      if (bareArgs + namedArgs.length != args.length) return false;
+    }
+    if (bareArgs != args.bareCount) return false;
+
+    if (namedArgs == null) return true;
+
+    for (int i = 0; i < namedArgs.length; i++) {
+      if (namedArgs[i] != args.getName(bareArgs + i)) return false;
+    }
+    return true;
+  }
+
+  void addMembers(List<Member> members, CallingContext context, Value target,
+      Arguments args) {
+    // TODO(jimhug): In checked mode include parameter types to determine
+    // need for varCall.
+    for (var member in members) {
+      // check that this is a "perfect" match - or require a var call
+      // TODO(jimhug): Add support of "perfect matches" even with names
+      if (!(member.parameters.length == bareArgs && namedArgs == null)) {
+        needsVarCall = true;
+      }
+      // TODO(jimhug): Should create a less specific version of args.
+      if (member.canInvoke(context, args)) {
+        if (member.isMethod) {
+          returnType = MemberSet.unionTypes(returnType, member.returnType);
+          member.declaringType.genMethod(member);
+        } else {
+          needsVarCall = true;
+          returnType = world.varType;
+        }
+      }
+    }
+    if (returnType == null) {
+      // TODO(jimhug): Warning here for no match anywhere in the world?
+      returnType = world.varType;
+    }
+  }
+}