implement opassign, fix bugs in pre/postfix, introduce a let* helper

lib/runtime/dart/_js_helper.js

Index: lib/runtime/dart/_js_helper.js
diff --git a/lib/runtime/dart/_js_helper.js b/lib/runtime/dart/_js_helper.js
index b6a6dcd6d63505b71c897408066f0378d113f2bb..916f02a28223d4e56dd5da55002f0b1eaa284c33 100644
--- a/lib/runtime/dart/_js_helper.js
+++ b/lib/runtime/dart/_js_helper.js
@@ -560,7 +560,7 @@ var _js_helper;
         return null;
       if (match[core.$get](dart.notNull(match[core.$length]) - 1) != null)
         return null;
-      match[core.$length] = 1;
+      match[core.$length] = dart.notNull(match[core.$length]) - 1;
       return new _MatchImplementation(this, dart.as(match, core.List$(core.String)));
     }
     matchAsPrefix(string, start) {
@@ -818,7 +818,7 @@ var _js_helper;
         code = dart.as(dart.dinvoke(receiver, 'codeUnitAt', dart.notNull(i) + 1), core.int);
         if ((dart.notNull(code) & ~1023) == 56320) {
           buffer.write(dart.dinvokef(onNonMatch, dart.dinvoke(receiver, 'substring', i, dart.notNull(i) + 2)));
-          i = 2;
+          i = dart.notNull(i) + 2;
           continue;
         }
       }
@@ -1539,8 +1539,9 @@ var _js_helper;
         if (!dart.is(arguments$, _interceptors.JSArray))
           arguments$ = new core.List.from(arguments$);
       } else {
-        arguments$ = new core.List.from([victim]);
-        arguments$[core.$addAll](arguments$);
+        let _$ = new core.List.from([victim]);
+        _$[core.$addAll](arguments$);
+        arguments$ = _$;
         if (this.cachedInterceptor != null)
           receiver = this.cachedInterceptor;
       }
@@ -1570,8 +1571,9 @@ var _js_helper;
           providedArgumentCount = arguments$[core.$length];
         }
       } else {
-        arguments$ = new core.List.from([victim]);
-        arguments$[core.$addAll](arguments$);
+        let _$ = new core.List.from([victim]);
+        _$[core.$addAll](arguments$);
+        arguments$ = _$;
         if (this.cachedInterceptor != null)
           receiver = this.cachedInterceptor;
         providedArgumentCount = dart.notNull(arguments$[core.$length]) - 1;
@@ -1678,11 +1680,8 @@ var _js_helper;
           positions.set(this.parameterName(index), index);
         }
         let index = 0;
-        ((_$) => {
-          _$[core.$sort]();
-          return _$;
-        })(positions.keys[core.$toList]())[core.$forEach](((name) => {
-          this.cachedSortedIndices[core.$set](((x$) => index = dart.notNull(x$) + 1, x$)(index), positions.get(name));
+        ((_$) => (_$ = positions.keys[core.$toList](), _$[core.$sort](), _$))()[core.$forEach](((name) => {
+          this.cachedSortedIndices[core.$set](((x$) => (x$ = index, index = dart.notNull(x$) + 1, x$))(), positions.get(name));
         }).bind(this));
       }
       return dart.as(this.cachedSortedIndices[core.$get](unsortedIndex), core.int);
@@ -1717,8 +1716,8 @@ var _js_helper;
   let _mangledNameMatchesType = Symbol('_mangledNameMatchesType');
   class Primitives extends core.Object {
     static initializeStatics(id) {
-      Primitives.mirrorFunctionCacheName = `_${id}`;
-      Primitives.mirrorInvokeCacheName = `_${id}`;
+      Primitives.mirrorFunctionCacheName = core.String['+'](Primitives.mirrorFunctionCacheName, `_${id}`);
+      Primitives.mirrorInvokeCacheName = core.String['+'](Primitives.mirrorInvokeCacheName, `_${id}`);
     }
     static objectHashCode(object) {
       let hash = dart.as(object.$identityHash, core.int);
@@ -1857,7 +1856,7 @@ var _js_helper;
       let result = "";
       let kMaxApply = 500;
       let end = array[core.$length];
-      for (let i = 0; dart.notNull(i) < dart.notNull(end); i = kMaxApply) {
+      for (let i = 0; dart.notNull(i) < dart.notNull(end); i = dart.notNull(i) + dart.notNull(kMaxApply)) {
         let subarray = null;
         if (dart.notNull(end) <= dart.notNull(kMaxApply)) {
           subarray = array;
@@ -2020,7 +2019,7 @@ var _js_helper;
       let arguments$ = new core.List.from([]);
       let namedArgumentList = new core.List.from([]);
       if (positionalArguments != null) {
-        argumentCount = positionalArguments[core.$length];
+        argumentCount = dart.notNull(argumentCount) + dart.notNull(positionalArguments[core.$length]);
         arguments$[core.$addAll](positionalArguments);
       }
       let names = '';
@@ -2533,8 +2532,8 @@ var _js_helper;
     let index = 0;
     let length = getLength(keyValuePairs);
     while (dart.notNull(index) < dart.notNull(length)) {
-      let key = getIndex(keyValuePairs, ((x$) => index = dart.notNull(x$) + 1, x$)(index));
-      let value = getIndex(keyValuePairs, ((x$) => index = dart.notNull(x$) + 1, x$)(index));
+      let key = getIndex(keyValuePairs, ((x$) => (x$ = index, index = dart.notNull(x$) + 1, x$))());
+      let value = getIndex(keyValuePairs, ((x$) => (x$ = index, index = dart.notNull(x$) + 1, x$))());
       result.set(key, value);
     }
     return result;
@@ -2590,7 +2589,7 @@ var _js_helper;
         this.$initialize();
       } : Closure.isCsp ? function(a, b, c, d) {
         this.$initialize(a, b, c, d);
-      } : new Function("a", "b", "c", "d", "this.$initialize(a,b,c,d);" + ((x$) => Closure.functionCounter = dart.notNull(x$) + 1, x$)(Closure.functionCounter));
+      } : new Function("a", "b", "c", "d", "this.$initialize(a,b,c,d);" + ((x$) => (x$ = Closure.functionCounter, Closure.functionCounter = dart.notNull(x$) + 1, x$))());
       prototype.constructor = constructor;
       constructor.prototype = prototype;
       let trampoline = func;
@@ -2711,11 +2710,11 @@ var _js_helper;
         return Closure.cspForwardCall(arity, isSuperCall, stubName, func);
       }
       if (arity == 0) {
-        return new Function('return function(){' + `return this.${BoundClosure.selfFieldName()}.${stubName}();` + `${((x$) => Closure.functionCounter = dart.notNull(x$) + 1, x$)(Closure.functionCounter)}` + '}')();
+        return new Function('return function(){' + `return this.${BoundClosure.selfFieldName()}.${stubName}();` + `${((x$) => (x$ = Closure.functionCounter, Closure.functionCounter = dart.notNull(x$) + 1, x$))()}` + '}')();
       }
       dart.assert(1 <= dart.notNull(arity) && dart.notNull(arity) < 27);
       let arguments$ = "abcdefghijklmnopqrstuvwxyz".split("").splice(0, arity).join(",");
-      return new Function(`return function(${arguments$}){` + `return this.${BoundClosure.selfFieldName()}.${stubName}(${arguments$});` + `${((x$) => Closure.functionCounter = dart.notNull(x$) + 1, x$)(Closure.functionCounter)}` + '}')();
+      return new Function(`return function(${arguments$}){` + `return this.${BoundClosure.selfFieldName()}.${stubName}(${arguments$});` + `${((x$) => (x$ = Closure.functionCounter, Closure.functionCounter = dart.notNull(x$) + 1, x$))()}` + '}')();
     }
     static cspForwardInterceptedCall(arity, isSuperCall, name, func) {
       let getSelf = _foreign_helper.RAW_DART_FUNCTION_REF(BoundClosure.selfOf);
@@ -2799,11 +2798,11 @@ var _js_helper;
         return Closure.cspForwardInterceptedCall(arity, isSuperCall, stubName, func);
       }
       if (arity == 1) {
-        return new Function('return function(){' + `return this.${selfField}.${stubName}(this.${receiverField});` + `${((x$) => Closure.functionCounter = dart.notNull(x$) + 1, x$)(Closure.functionCounter)}` + '}')();
+        return new Function('return function(){' + `return this.${selfField}.${stubName}(this.${receiverField});` + `${((x$) => (x$ = Closure.functionCounter, Closure.functionCounter = dart.notNull(x$) + 1, x$))()}` + '}')();
       }
       dart.assert(1 < dart.notNull(arity) && dart.notNull(arity) < 28);
       let arguments$ = "abcdefghijklmnopqrstuvwxyz".split("").splice(0, dart.notNull(arity) - 1).join(",");
-      return new Function(`return function(${arguments$}){` + `return this.${selfField}.${stubName}(this.${receiverField}, ${arguments$});` + `${((x$) => Closure.functionCounter = dart.notNull(x$) + 1, x$)(Closure.functionCounter)}` + '}')();
+      return new Function(`return function(${arguments$}){` + `return this.${selfField}.${stubName}(this.${receiverField}, ${arguments$});` + `${((x$) => (x$ = Closure.functionCounter, Closure.functionCounter = dart.notNull(x$) + 1, x$))()}` + '}')();
     }
     toString() {
       return "Closure";
@@ -3358,42 +3357,47 @@ var _js_helper;
       if (this.parameterTypes != null) {
         for (let i = 0; dart.notNull(i) < dart.notNull(this.parameterTypes[core.$length]); i = dart.notNull(i) + 1) {
           let type = this.parameterTypes[core.$get](i);
-          if (needsComma)
-            result = ', ';
-          result = `${type}`;
+          if (needsComma) {
+            result = core.String['+'](result, ', ');
+          }
+          result = core.String['+'](result, `${type}`);
           needsComma = true;
         }
       }
       if (dart.notNull(this.optionalParameterTypes != null) && !dart.notNull(this.optionalParameterTypes[core.$isEmpty])) {
-        if (needsComma)
-          result = ', ';
+        if (needsComma) {
+          result = core.String['+'](result, ', ');
+        }
         needsComma = false;
-        result = '[';
+        result = core.String['+'](result, '[');
         for (let i = 0; dart.notNull(i) < dart.notNull(this.optionalParameterTypes[core.$length]); i = dart.notNull(i) + 1) {
           let type = this.optionalParameterTypes[core.$get](i);
-          if (needsComma)
-            result = ', ';
-          result = `${type}`;
+          if (needsComma) {
+            result = core.String['+'](result, ', ');
+          }
+          result = core.String['+'](result, `${type}`);
           needsComma = true;
         }
-        result = ']';
+        result = core.String['+'](result, ']');
       } else if (this.namedParameters != null) {
-        if (needsComma)
-          result = ', ';
+        if (needsComma) {
+          result = core.String['+'](result, ', ');
+        }
         needsComma = false;
-        result = '{';
+        result = core.String['+'](result, '{');
         let keys = _js_names.extractKeys(this.namedParameters);
         for (let i = 0; dart.notNull(i) < dart.notNull(keys[core.$length]); i = dart.notNull(i) + 1) {
           let name = keys[core.$get](i);
-          if (needsComma)
-            result = ', ';
+          if (needsComma) {
+            result = core.String['+'](result, ', ');
+          }
           let rti = dart.dinvoke(this.namedParameters[name], 'toRti');
-          result = `${rti} ${name}`;
+          result = core.String['+'](result, `${rti} ${name}`);
           needsComma = true;
         }
-        result = '}';
+        result = core.String['+'](result, '}');
       }
-      result = `) -> ${this.returnType}`;
+      result = core.String['+'](result, `) -> ${this.returnType}`);
       return result;
     }
   }
@@ -3585,39 +3589,39 @@ var _js_helper;
       let sep = '';
       if (this[_hasArguments]) {
         for (let argument of this[_arguments]) {
-          s = sep;
-          s = this[_convert](argument);
+          s = core.String['+'](s, sep);
+          s = core.String['+'](s, this[_convert](argument));
           sep = ', ';
         }
       }
       if (this[_hasOptionalArguments]) {
-        s = `${sep}[`;
+        s = core.String['+'](s, `${sep}[`);
         sep = '';
         for (let argument of this[_optionalArguments]) {
-          s = sep;
-          s = this[_convert](argument);
+          s = core.String['+'](s, sep);
+          s = core.String['+'](s, this[_convert](argument));
           sep = ', ';
         }
-        s = ']';
+        s = core.String['+'](s, ']');
       }
       if (this[_hasNamedArguments]) {
-        s = `${sep}{`;
+        s = core.String['+'](s, `${sep}{`);
         sep = '';
         for (let name of _js_names.extractKeys(this[_namedArguments])) {
-          s = sep;
-          s = `${name}: `;
-          s = this[_convert](this[_namedArguments][name]);
+          s = core.String['+'](s, sep);
+          s = core.String['+'](s, `${name}: `);
+          s = core.String['+'](s, this[_convert](this[_namedArguments][name]));
           sep = ', ';
         }
-        s = '}';
+        s = core.String['+'](s, '}');
       }
-      s = ') -> ';
+      s = core.String['+'](s, ') -> ');
       if (this[_isVoid]) {
-        s = 'void';
+        s = core.String['+'](s, 'void');
       } else if (this[_hasReturnType]) {
-        s = this[_convert](this[_returnType]);
+        s = core.String['+'](s, this[_convert](this[_returnType]));
       } else {
-        s = 'dynamic';
+        s = core.String['+'](s, 'dynamic');
       }
       return this[_cachedToString] = `${s}`;
     }