move fancy_syntax into Dart SVN

pkg/polymer_expression/lib/expression.dart

+// 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_expression.expression;
+
+import 'visitor.dart';
+
+// Helper functions for building expression trees programmatically
+
+EmptyExpression empty() => new 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 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);
+Invoke invoke(Expression e, String m, [List<Expression> a]) =>
+    new Invoke(e, m, a);
+InExpression inExpr(Expression l, Expression r) => new InExpression(l, r);
+
+
+class AstFactory {
+  EmptyExpression empty() => new 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);
+
+  Invoke invoke(Expression e, String m, [List<Expression> a]) =>
+      new Invoke(e, m, a);
+
+  InExpression inExpr(Expression l, Expression r) => new InExpression(l, r);
+}
+
+/// Base class for all expressions
+abstract class Expression {
+  accept(Visitor v);
+}
+
+class EmptyExpression extends Expression {
+  accept(Visitor v) => v.visitEmptyExpression(this);
+  bool operator ==(o) => o is EmptyExpression;
+}
+
+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 MapLiteral extends Expression {
+  final List<MapLiteralEntry> entries;
+
+  MapLiteral(this.entries);
+
+  accept(Visitor v) => v.visitMapLiteral(this);
+
+  String toString() => "{$entries}";
+
+  bool operator ==(o) => o is MapLiteral && _listEquals(o.entries, entries);
+}
+
+class MapLiteralEntry extends Expression {
+  final Literal key;
+  final Expression entryValue;
+
+  MapLiteralEntry(this.key, this.entryValue);
+
+  accept(Visitor v) => v.visitMapLiteralEntry(this);
+
+  String toString() => "$key: $entryValue";
+
+  bool operator ==(o) => o is MapLiteralEntry && o.key == key
+      && o.entryValue == entryValue;
+}
+
+class ParenthesizedExpression extends Expression {
+  final Expression child;
+
+  ParenthesizedExpression(this.child);
+
+  accept(Visitor v) => v.visitParenthesizedExpression(this);
+
+  String toString() => '($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 $child';
+
+  bool operator ==(o) => o is UnaryOperator && o.operator == operator
+      && o.child == child;
+}
+
+class BinaryOperator extends Expression {
+  final String operator;
+  final Expression left;
+  final Expression right;
+
+  BinaryOperator(this.left, this.operator, this.right);
+
+  accept(Visitor v) => v.visitBinaryOperator(this);
+
+  String toString() => '($left $operator $right)';
+
+  bool operator ==(o) => o is BinaryOperator && o.operator == operator
+      && o.left == left && o.right == right;
+}
+
+class InExpression extends Expression {
+  final Expression left;
+  final Expression right;
+
+  InExpression(this.left, this.right);
+
+  accept(Visitor v) => v.visitInExpression(this);
+
+  String toString() => '($left in $right)';
+
+  bool operator ==(o) => o is InExpression && o.left == left
+      && o.right == right;
+}
+
+/**
+ * Represents a function or method invocation. If [method] is null, then
+ * [receiver] is an expression that should evaluate to a function. If [method]
+ * is not null, then [receiver] is an expression that should evaluate to an
+ * object that has an appropriate method.
+ */
+class Invoke extends Expression {
+  final Expression receiver;
+  final String method;
+  final List<Expression> arguments;
+
+  Invoke(this.receiver, this.method, [this.arguments]);
+
+  accept(Visitor v) => v.visitInvoke(this);
+
+  bool get isGetter => arguments == null;
+
+  String toString() => '$receiver.$method($arguments)';
+
+  bool operator ==(o) =>
+      o is Invoke
+      && o.receiver == receiver
+      && o.method == method
+      && _listEquals(o.arguments, 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;
+}