implement null aware ops, fixes #249

lib/runtime/dart/collection.js

 dart_library.library('dart/collection', null, /* Imports */[
   "dart_runtime/dart",
   'dart/core'
 ], /* Lazy imports */[
   'dart/_internal',
   'dart/_js_helper',
   'dart/math'
 ], function(exports, dart, core, _internal, _js_helper, math) {
   'use strict';
   let dartx = dart.dartx;
@@ skipping 2272 matching lines @@
     class MapBase extends dart.mixin(core.Object, MapMixin$(K, V)) {}
     return MapBase;
   });
   let MapBase = MapBase$();
   let _UnmodifiableMapMixin$ = dart.generic(function(K, V) {
     class _UnmodifiableMapMixin extends core.Object {
       set(key, value) {
         dart.as(key, K);
         dart.as(value, V);
         dart.throw(new core.UnsupportedError("Cannot modify unmodifiable map"));
+        return value;
       }
       addAll(other) {
         dart.as(other, core.Map$(K, V));
         dart.throw(new core.UnsupportedError("Cannot modify unmodifiable map"));
       }
       clear() {
         dart.throw(new core.UnsupportedError("Cannot modify unmodifiable map"));
       }
       remove(key) {
         dart.throw(new core.UnsupportedError("Cannot modify unmodifiable map"));
@@ skipping 104 matching lines @@
       MapView(map) {
         this[_map] = map;
       }
       get(key) {
         return this[_map].get(key);
       }
       set(key, value) {
         dart.as(key, K);
         dart.as(value, V);
         this[_map].set(key, value);
+        return value;
       }
       addAll(other) {
         dart.as(other, core.Map$(K, V));
         this[_map].addAll(other);
       }
       clear() {
         this[_map].clear();
       }
       putIfAbsent(key, ifAbsent) {
         dart.as(key, K);
@@ skipping 890 matching lines @@
     dart.setSignature(_SplayTreeMapNode, {
       constructors: () => ({_SplayTreeMapNode: [_SplayTreeMapNode$(K, V), [K, V]]})
     });
     return _SplayTreeMapNode;
   });
   let _SplayTreeMapNode = _SplayTreeMapNode$();
   let _dummy = Symbol('_dummy');
   let _root = Symbol('_root');
   let _count = Symbol('_count');
   let _splayCount = Symbol('_splayCount');
+  let _compare = Symbol('_compare');
   let _splay = Symbol('_splay');
-  let _compare = Symbol('_compare');
   let _splayMin = Symbol('_splayMin');
   let _splayMax = Symbol('_splayMax');
   let _addNewRoot = Symbol('_addNewRoot');
   let _first = Symbol('_first');
   let _last = Symbol('_last');
   let _clear = Symbol('_clear');
   let _SplayTree$ = dart.generic(function(K) {
     class _SplayTree extends core.Object {
       _SplayTree() {
         this[_dummy] = new (_SplayTreeNode$(K))(null);
@@ skipping 215 matching lines @@
       }
       remove(key) {
         if (!dart.notNull(this[_validKey](key)))
           return null;
         let mapRoot = dart.as(this[_remove](dart.as(key, K)), _SplayTreeMapNode);
         if (mapRoot != null)
           return dart.as(mapRoot.value, V);
         return null;
       }
       set(key, value) {
-        dart.as(key, K);
-        dart.as(value, V);
-        if (key == null)
-          dart.throw(new core.ArgumentError(key));
-        let comp = this[_splay](key);
-        if (comp == 0) {
-          let mapRoot = dart.as(this[_root], _SplayTreeMapNode);
-          mapRoot.value = value;
-          return;
-        }
-        this[_addNewRoot](new (_SplayTreeMapNode$(K, dart.dynamic))(key, value), comp);
+        ((() => {
+          dart.as(key, K);
+          dart.as(value, V);
+          if (key == null)
+            dart.throw(new core.ArgumentError(key));
+          let comp = this[_splay](key);
+          if (comp == 0) {
+            let mapRoot = dart.as(this[_root], _SplayTreeMapNode);
+            mapRoot.value = value;
+            return;
+          }
+          this[_addNewRoot](new (_SplayTreeMapNode$(K, dart.dynamic))(key, value), comp);
+        }).bind(this))();
+        return value;
       }
       putIfAbsent(key, ifAbsent) {
         dart.as(key, K);
         dart.as(ifAbsent, dart.functionType(V, []));
         if (key == null)
           dart.throw(new core.ArgumentError(key));
         let comp = this[_splay](key);
         if (comp == 0) {
           let mapRoot = dart.as(this[_root], _SplayTreeMapNode);
           return dart.as(mapRoot.value, V);
@@ skipping 635 matching lines @@
             this[_strings] = strings = _HashMap$()._newHashTable();
           this[_addHashTableEntry](strings, key, value);
         } else if (dart.notNull(_HashMap$()._isNumericKey(key))) {
           let nums = this[_nums];
           if (nums == null)
             this[_nums] = nums = _HashMap$()._newHashTable();
           this[_addHashTableEntry](nums, key, value);
         } else {
           this[_set](key, value);
         }
+        return value;
       }
       [_set](key, value) {
         dart.as(key, K);
         dart.as(value, V);
         let rest = this[_rest];
         if (rest == null)
           this[_rest] = rest = _HashMap$()._newHashTable();
         let hash = this[_computeHashCode](key);
         let bucket = rest[hash];
         if (bucket == null) {
@@ skipping 242 matching lines @@
       }
       get(key) {
         if (!dart.notNull(this[_validKey](key)))
           return null;
         return super[_get](key);
       }
       set(key, value) {
         dart.as(key, K);
         dart.as(value, V);
         super[_set](key, value);
+        return value;
       }
       containsKey(key) {
         if (!dart.notNull(this[_validKey](key)))
           return false;
         return super[_containsKey](key);
       }
       remove(key) {
         if (!dart.notNull(this[_validKey](key)))
           return null;
         return super[_remove](key);
@@ skipping 209 matching lines @@
             this[_strings] = strings = _LinkedHashMap$()._newHashTable();
           this[_addHashTableEntry](strings, key, value);
         } else if (dart.notNull(_LinkedHashMap$()._isNumericKey(key))) {
           let nums = this[_nums];
           if (nums == null)
             this[_nums] = nums = _LinkedHashMap$()._newHashTable();
           this[_addHashTableEntry](nums, key, value);
         } else {
           this[_set](key, value);
         }
+        return value;
       }
       [_set](key, value) {
         dart.as(key, K);
         dart.as(value, V);
         let rest = this[_rest];
         if (rest == null)
           this[_rest] = rest = _LinkedHashMap$()._newHashTable();
         let hash = this[_computeHashCode](key);
         let bucket = rest[hash];
         if (bucket == null) {
@@ skipping 232 matching lines @@
       }
       get(key) {
         if (!dart.notNull(this[_validKey](key)))
           return null;
         return super[_get](key);
       }
       set(key, value) {
         dart.as(key, K);
         dart.as(value, V);
         super[_set](key, value);
+        return value;
       }
       containsKey(key) {
         if (!dart.notNull(this[_validKey](key)))
           return false;
         return super[_containsKey](key);
       }
       remove(key) {
         if (!dart.notNull(this[_validKey](key)))
           return null;
         return super[_remove](key);
@@ skipping 1037 matching lines @@
   exports.LinkedHashMapKeyIterable$ = LinkedHashMapKeyIterable$;
   exports.LinkedHashMapKeyIterable = LinkedHashMapKeyIterable;
   exports.LinkedHashMapKeyIterator$ = LinkedHashMapKeyIterator$;
   exports.LinkedHashMapKeyIterator = LinkedHashMapKeyIterator;
   exports.HashSetIterator$ = HashSetIterator$;
   exports.HashSetIterator = HashSetIterator;
   exports.LinkedHashSetCell = LinkedHashSetCell;
   exports.LinkedHashSetIterator$ = LinkedHashSetIterator$;
   exports.LinkedHashSetIterator = LinkedHashSetIterator;
 });