Add support for the node net module.

frog/lib/node/nodeimpl.dart

+// Copyright (c) 2011, 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.
+
+// Utilities used by the node library.
+
+#library('nodeimpl');
+
+// Helpers for read-only collections of native objects
+
+// Takes a JavaScript object, returns a dart object
+// Used to wrap list elements and map values
+
+typedef var NativeValueWrapper(var v);
+
+class NativeListBase<E> implements List<E>{
+  var _list;
+  NativeListBase(this._list);
+  int get length() => _length(_list);
+  int _length(var list) native "return list.length;";
+  abstract E operator[](int index);
+
+  bool isEmpty() => length == 0;
+  
+  void forEach(void f(E e)) {
+    int len = length;
+    for (int i = 0; i < len; i++) {
+      f(this[i]);
+    }
+  }
+}
+
+class NativeList<E> extends NativeListBase<E> {
+  NativeValueWrapper _ctor;
+  NativeList(var list, this._ctor) : super(list);
+  E operator[](int index) => _ctor(_at(_list, index));
+  var _at(var list, int index) native "return list[index];";
+}
+
+class NativeListPrimitiveElement<E> extends NativeListBase<E> {
+  NativeListPrimitiveElement(var list) : super(list);
+  E operator[](int index) => _at(_list, index);
+  E _at(var list, int index) native "return list[index];"; 
+}
+
+class NativeMapBase<V> implements Map<String, V> {
+  var _map;
+  NativeMapBase(this._map);
+  int get length() => _length(_map);
+  int _length(var map) native "return map.length;";
+  
+  bool isEmpty() => length == 0;
+  
+  abstract V operator[](String key);
+
+  Collection<String> getKeys() {
+    List<String> keys = new List<String>();
+    _forEachKey(_map, (String key) => keys.add(key));
+    return keys;
+  }
+  
+  Collection<V> getValues() {
+    List<V> values = new List<V>();
+    _forEachKey(_map, (String key) => values.add(this[key]));
+    return values;
+  }
+  
+  void forEach(void f(String key, V value)) =>
+      _forEachKey(_map, (String k) => f(k, this[k]));
+  
+  void _forEachKey(var map, void f(String key))
+    native """
+      for (var i in map) {
+        if (map.hasOwnProperty(i)) {
+          f(i);
+        }
+      }
+    """;
+}
+
+class NativeMap<V> extends NativeMapBase<V> {
+  NativeValueWrapper _ctor;  
+  NativeMap(var map, this._ctor) : super(map);
+  V operator[](String key) => _ctor(_at(_map, key));
+  var _at(var map, String key) native "return map[key];";
+}
+
+class NativeMapPrimitiveValue<V> extends NativeMapBase<V> {
+  NativeMapPrimitiveValue(map) : super(map);
+  V operator[](String key) => _at(_map, key);
+  var _at(var map, String key) native "return map[key];";
+}
+
+String NativeGetStringProperty(var object, String key)
+  native "var v = object[key];return v == undefined ? null : v;";
+
+bool NativeGetBoolProperty(var object, String key)
+  native "var v = object[key];return v == undefined ? null : v;";
+
+int NativeGetIntProperty(var object, String key)
+  native "var v = object[key];return v == undefined ? null : v;";
+
+double NativeGetDoubleProperty(var object, String key)
+  native "var v = object[key];return v == undefined ? null : v;";
+
+
+// Fixed size List utilities
+
+class FixedLists {
+  static void getRangeCheck(int srcLength, int start, int length) {
+    if (length < 0) {
+      throw new IllegalArgumentException();
+    }
+    int end = start + length;
+    if (start < 0 || start >= srcLength) {
+      throw new IndexOutOfRangeException(start);
+    }
+    if (end < 0 || end > srcLength) {
+      throw new IndexOutOfRangeException(end);
+    }
+  }
+
+  static int indexOf(List list, var element, int start) {
+    if (start == null) {
+      start = 0;
+    }
+    int end = list.length;
+    for (int i = start; i < end; i++) {
+      if (list[i] == element) {
+        return i;
+      }
+    }
+    return -1;
+  }
+
+  static int lastIndexOf(List list, var element, int start) {
+    int end = start == null ? list.length : start;
+    for (int i = end-1; i >= 0; i--) {
+      if (list[i] == element) {
+        return i;
+      }
+    }
+    return -1;
+  }
+
+  static num last(List list) {
+    int end = list.length;
+    if (end <= 0) {
+      throw new IndexOutOfRangeException(0);
+    }
+    return list[end-1]; 
+  }
+
+  static void forEach(List list, void f(var element)) {
+    int len = list.length;
+    for (int i = 0; i < len; i++) {
+      f(list[i]);
+    }
+  }
+
+  static Collection filter(List list, bool f(element), List ctor(int length)) {
+    // Assume computation is more expensive than allocation, so use a
+    // temporary growable list to store the filtered results.
+    // (The alternative would be to make two passes through the list.)
+    List filtered = [];
+    int len = list.length;
+    for (int i = 0; i < len; i++) {
+      var e = list[i];
+      if (f(e)) {
+        filtered.add(e);
+      }
+    }
+    int filteredLength = filtered.length;
+    List result = ctor(filteredLength);
+    for (int i = 0; i < len; i++) {
+      result[i] = filtered[i];
+    }
+    return result;
+  }
+
+  static bool every(List list, bool f(int element)) {
+    int len = list.length;
+    for (int i = 0; i < len; i++) {
+      if (! f(list[i])) {
+        return false;
+      }
+    }
+    return true;
+  }
+  
+  static Collection map(List list, f(element), List result) {
+    int len = list.length;
+    for (int i = 0; i < len; i++) {
+      result[i] = f(list[i]);
+    }
+    return result;
+  }
+  
+
+  static bool some(List list, bool f(num element)) {
+    int len = list.length;
+    for (int i = 0; i < len; i++) {
+      if (f(list[i])) {
+        return true;
+      }
+    }
+    return false;
+  }
+
+  static bool isEmpty(List list) => list.length == 0;
+}