Add observatory_pub_packages snapshot to third_party

observatory_pub_packages/polymer_expressions/expression.dart

Index: observatory_pub_packages/polymer_expressions/expression.dart
===================================================================
--- observatory_pub_packages/polymer_expressions/expression.dart	(revision 0)
+++ observatory_pub_packages/polymer_expressions/expression.dart	(working copy)
@@ -0,0 +1,368 @@
+// Copyright (c) 2013, 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.
+
+library polymer_expressions.expression;
+
+import 'visitor.dart';
+
+// Helper functions for building expression trees programmatically
+
+EmptyExpression empty() => const EmptyExpression();
+Literal literal(v) => new Literal(v);
+ListLiteral listLiteral(List<Expression> items) => new ListLiteral(items);
+MapLiteral mapLiteral(List<MapLiteralEntry> entries) => new MapLiteral(entries);
+MapLiteralEntry mapLiteralEntry(Literal key, Expression value) =>
+    new MapLiteralEntry(key, value);
+Identifier ident(String v) => new Identifier(v);
+ParenthesizedExpression paren(Expression e) => new ParenthesizedExpression(e);
+UnaryOperator unary(String op, Expression e) => new UnaryOperator(op, e);
+BinaryOperator binary(Expression l, String op, Expression r) =>
+    new BinaryOperator(l, op, r);
+Getter getter(Expression e, String m) => new Getter(e, m);
+Index index(Expression e, Expression a) => new Index(e, a);
+Invoke invoke(Expression e, String m, List<Expression> a) =>
+    new Invoke(e, m, a);
+InExpression inExpr(Expression l, Expression r) => new InExpression(l, r);
+AsExpression asExpr(Expression l, Expression r) => new AsExpression(l, r);
+TernaryOperator ternary(Expression c, Expression t, Expression f) =>
+    new TernaryOperator(c, t, f);
+
+class AstFactory {
+  EmptyExpression empty() => const EmptyExpression();
+
+  Literal literal(v) => new Literal(v);
+
+  MapLiteral mapLiteral(List<MapLiteralEntry> entries) =>
+      new MapLiteral(entries);
+
+  MapLiteralEntry mapLiteralEntry(Literal key, Expression value) =>
+      new MapLiteralEntry(key, value);
+
+  Identifier identifier(String v) => new Identifier(v);
+
+  ParenthesizedExpression parenthesized(Expression e) =>
+      new ParenthesizedExpression(e);
+
+  UnaryOperator unary(String op, Expression e) => new UnaryOperator(op, e);
+
+  BinaryOperator binary(Expression l, String op, Expression r) =>
+      new BinaryOperator(l, op, r);
+
+  TernaryOperator ternary(Expression c, Expression t, Expression f) =>
+      new TernaryOperator(c, t, f);
+
+  Getter getter(Expression g, String n) => new Getter(g, n);
+
+  Index index(Expression e, Expression a) => new Index(e, a);
+
+  Invoke invoke(Expression e, String m, List<Expression> a) =>
+      new Invoke(e, m, a);
+
+  InExpression inExpr(Expression l, Expression r) => new InExpression(l, r);
+
+  AsExpression asExpr(Expression l, Expression r) => new AsExpression(l, r);
+}
+
+/// Base class for all expressions
+abstract class Expression {
+  const Expression();
+  accept(Visitor v);
+}
+
+abstract class HasIdentifier {
+  String get identifier;
+  Expression get expr;
+}
+
+class EmptyExpression extends Expression {
+  const EmptyExpression();
+  accept(Visitor v) => v.visitEmptyExpression(this);
+}
+
+class Literal<T> extends Expression {
+  final T value;
+
+  Literal(this.value);
+
+  accept(Visitor v) => v.visitLiteral(this);
+
+  String toString() => (value is String) ? '"$value"' : '$value';
+
+  bool operator ==(o) => o is Literal<T> && o.value == value;
+
+  int get hashCode => value.hashCode;
+}
+
+class ListLiteral extends Expression {
+  final List<Expression> items;
+
+  ListLiteral(this.items);
+
+  accept(Visitor v) => v.visitListLiteral(this);
+
+  String toString() => "$items";
+
+  bool operator ==(o) => o is ListLiteral && _listEquals(o.items, items);
+
+  int get hashCode => _hashList(items);
+}
+
+class MapLiteral extends Expression {
+  final List<MapLiteralEntry> entries;
+
+  MapLiteral(this.entries);
+
+  accept(Visitor v) => v.visitMapLiteral(this);
+
+  String toString() => "{$entries}";
+
+  bool operator ==(o) => o is MapLiteral && _listEquals(o.entries, entries);
+
+  int get hashCode => _hashList(entries);
+}
+
+class MapLiteralEntry extends Expression {
+  final Literal key;
+  final Expression entryValue;
+
+  MapLiteralEntry(this.key, this.entryValue);
+
+  accept(Visitor v) => v.visitMapLiteralEntry(this);
+
+  String toString() => "$key: $entryValue";
+
+  bool operator ==(o) => o is MapLiteralEntry && o.key == key
+      && o.entryValue == entryValue;
+
+  int get hashCode => _JenkinsSmiHash.hash2(key.hashCode, entryValue.hashCode);
+}
+
+class ParenthesizedExpression extends Expression {
+  final Expression child;
+
+  ParenthesizedExpression(this.child);
+
+  accept(Visitor v) => v.visitParenthesizedExpression(this);
+
+  String toString() => '($child)';
+
+  bool operator ==(o) => o is ParenthesizedExpression && o.child == child;
+
+  int get hashCode => child.hashCode;
+}
+
+class Identifier extends Expression {
+  final String value;
+
+  Identifier(this.value);
+
+  accept(Visitor v) => v.visitIdentifier(this);
+
+  String toString() => value;
+
+  bool operator ==(o) => o is Identifier && o.value == value;
+
+  int get hashCode => value.hashCode;
+}
+
+class UnaryOperator extends Expression {
+  final String operator;
+  final Expression child;
+
+  UnaryOperator(this.operator, this.child);
+
+  accept(Visitor v) => v.visitUnaryOperator(this);
+
+  String toString() => '$operator $child';
+
+  bool operator ==(o) => o is UnaryOperator && o.operator == operator
+      && o.child == child;
+
+  int get hashCode => _JenkinsSmiHash.hash2(operator.hashCode, child.hashCode);
+}
+
+class BinaryOperator extends Expression {
+  final String operator;
+  final Expression left;
+  final Expression right;
+
+  BinaryOperator(this.left, this.operator, this.right);
+
+  accept(Visitor v) => v.visitBinaryOperator(this);
+
+  String toString() => '($left $operator $right)';
+
+  bool operator ==(o) => o is BinaryOperator && o.operator == operator
+      && o.left == left && o.right == right;
+
+  int get hashCode => _JenkinsSmiHash.hash3(operator.hashCode, left.hashCode,
+      right.hashCode);
+}
+
+class TernaryOperator extends Expression {
+  final Expression condition;
+  final Expression trueExpr;
+  final Expression falseExpr;
+
+  TernaryOperator(this.condition, this.trueExpr, this.falseExpr);
+
+  accept(Visitor v) => v.visitTernaryOperator(this);
+
+  String toString() => '($condition ? $trueExpr : $falseExpr)';
+
+  bool operator ==(o) => o is TernaryOperator
+      && o.condition == condition
+      && o.trueExpr == trueExpr
+      && o.falseExpr == falseExpr;
+
+  int get hashCode => _JenkinsSmiHash.hash3(condition.hashCode,
+      trueExpr.hashCode, falseExpr.hashCode);
+}
+
+class InExpression extends Expression implements HasIdentifier {
+  final Identifier left;
+  final Expression right;
+
+  InExpression(this.left, this.right);
+
+  accept(Visitor v) => v.visitInExpression(this);
+
+  String get identifier => left.value;
+
+  Expression get expr => right;
+
+  String toString() => '($left in $right)';
+
+  bool operator ==(o) => o is InExpression && o.left == left
+      && o.right == right;
+
+  int get hashCode => _JenkinsSmiHash.hash2(left.hashCode, right.hashCode);
+}
+
+class AsExpression extends Expression implements HasIdentifier {
+  final Expression left;
+  final Identifier right;
+
+  AsExpression(this.left, this.right);
+
+  accept(Visitor v) => v.visitAsExpression(this);
+
+  String get identifier => right.value;
+
+  Expression get expr => left;
+
+  String toString() => '($left as $right)';
+
+  bool operator ==(o) => o is AsExpression && o.left == left
+      && o.right == right;
+
+  int get hashCode => _JenkinsSmiHash.hash2(left.hashCode, right.hashCode);
+}
+
+class Index extends Expression {
+  final Expression receiver;
+  final Expression argument;
+
+  Index(this.receiver, this.argument);
+
+  accept(Visitor v) => v.visitIndex(this);
+
+  String toString() => '$receiver[$argument]';
+
+  bool operator ==(o) =>
+      o is Index
+      && o.receiver == receiver
+      && o.argument == argument;
+
+  int get hashCode =>
+      _JenkinsSmiHash.hash2(receiver.hashCode, argument.hashCode);
+}
+
+class Getter extends Expression {
+  final Expression receiver;
+  final String name;
+
+  Getter(this.receiver, this.name);
+
+  accept(Visitor v) => v.visitGetter(this);
+
+  String toString() => '$receiver.$name';
+
+  bool operator ==(o) =>
+      o is Getter
+      && o.receiver == receiver
+      && o.name == name;
+
+  int get hashCode => _JenkinsSmiHash.hash2(receiver.hashCode, name.hashCode);
+
+}
+
+/**
+ * Represents a function or method invocation. If [method] is null, then
+ * [receiver] is an expression that should evaluate to a function. If [method]
+ * is not null, then [receiver] is an expression that should evaluate to an
+ * object that has an appropriate method.
+ */
+class Invoke extends Expression {
+  final Expression receiver;
+  final String method;
+  final List<Expression> arguments;
+
+  Invoke(this.receiver, this.method, this.arguments) {
+    assert(arguments != null);
+  }
+
+  accept(Visitor v) => v.visitInvoke(this);
+
+  String toString() => '$receiver.$method($arguments)';
+
+  bool operator ==(o) =>
+      o is Invoke
+      && o.receiver == receiver
+      && o.method == method
+      && _listEquals(o.arguments, arguments);
+
+  int get hashCode => _JenkinsSmiHash.hash3(receiver.hashCode, method.hashCode,
+      _hashList(arguments));
+}
+
+bool _listEquals(List a, List b) {
+  if (a == b) return true;
+  if (a == null || b == null) return false;
+  if (a.length != b.length) return false;
+  for (int i = 0; i < a.length; i++) {
+    if (a[i] != b[i]) return false;
+  }
+  return true;
+}
+
+int _hashList(List l) {
+  var hash = l.fold(0,
+      (h, item) => _JenkinsSmiHash.combine(h, item.hashCode));
+  return _JenkinsSmiHash.finish(hash);
+}
+
+class _JenkinsSmiHash {
+  // TODO: Bug 11617- This class should be optimized and standardized elsewhere.
+
+  static int combine(int hash, int value) {
+    hash = 0x1fffffff & (hash + value);
+    hash = 0x1fffffff & (hash + ((0x0007ffff & hash) << 10));
+    return hash ^ (hash >> 6);
+  }
+
+  static int finish(int hash) {
+    hash = 0x1fffffff & (hash + ((0x03ffffff & hash) <<  3));
+    hash = hash ^ (hash >> 11);
+    return 0x1fffffff & (hash + ((0x00003fff & hash) << 15));
+  }
+
+  static int hash2(int a, int b) => finish(combine(combine(0, a), b));
+
+  static int hash3(int a, int b, int c) =>
+      finish(combine(combine(combine(0, a), b), c));
+
+  static int hash4(int a, int b, int c, int d) =>
+      finish(combine(combine(combine(combine(0, a), b), c), d));
+}