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

lib/runtime/dart/core.js

 var core;
 (function(exports) {
   'use strict';
   class Object {
     constructor() {
       let name = this.constructor.name;
       let init = this[name];
       let result = void 0;
       if (init)
         result = init.apply(this, arguments);
@@ skipping 159 matching lines @@
           addOneMillisecond = true;
           millisecond = 999;
         }
         let isUtc = false;
         if (match.get(8) != null) {
           isUtc = true;
           if (match.get(9) != null) {
             let sign = match.get(9) == '-' ? -1 : 1;
             let hourDifference = int.parse(match.get(10));
             let minuteDifference = parseIntOrZero(match.get(11));
-            minuteDifference = 60 * dart.notNull(hourDifference);
-            minute = dart.notNull(sign) * dart.notNull(minuteDifference);
+            minuteDifference = dart.notNull(minuteDifference) + 60 * dart.notNull(hourDifference);
+            minute = dart.notNull(minute) - dart.notNull(sign) * dart.notNull(minuteDifference);
           }
         }
         let millisecondsSinceEpoch = DateTime[_brokenDownDateToMillisecondsSinceEpoch](years, month, day, hour, minute, second, millisecond, isUtc);
         if (millisecondsSinceEpoch == null) {
           throw new FormatException("Time out of range", formattedString);
         }
-        if (addOneMillisecond)
+        if (addOneMillisecond) {
           millisecondsSinceEpoch = dart.notNull(millisecondsSinceEpoch) + 1;
+        }
         return new DateTime.fromMillisecondsSinceEpoch(millisecondsSinceEpoch, {isUtc: isUtc});
       } else {
         throw new FormatException("Invalid date format", formattedString);
       }
     }
     fromMillisecondsSinceEpoch(millisecondsSinceEpoch, opts) {
       let isUtc = opts && 'isUtc' in opts ? opts.isUtc : false;
       this.millisecondsSinceEpoch = millisecondsSinceEpoch;
       this.isUtc = isUtc;
       if (dart.notNull(millisecondsSinceEpoch.abs()) > dart.notNull(DateTime[_MAX_MILLISECONDS_SINCE_EPOCH])) {
@@ skipping 734 matching lines @@
       this.offset = offset;
     }
     toString() {
       let report = "FormatException";
       if (dart.notNull(this.message != null) && dart.notNull("" != this.message)) {
         report = `${report}: ${this.message}`;
       }
       let offset = this.offset;
       if (!(typeof this.source == 'string')) {
         if (offset != -1) {
-          report = ` (at offset ${offset})`;
+          report = String['+'](report, ` (at offset ${offset})`);
         }
         return report;
       }
       if (offset != -1 && (dart.notNull(offset) < 0 || offset['>'](dart.dload(this.source, 'length')))) {
         offset = -1;
       }
       if (offset == -1) {
         let source = dart.as(this.source, String);
         if (dart.notNull(source.length) > 78) {
           source = String['+'](source.substring(0, 75), "...");
@@ skipping 11 matching lines @@
           }
           lineStart = dart.notNull(i) + 1;
           lastWasCR = false;
         } else if (char == 13) {
           lineNum = dart.notNull(lineNum) + 1;
           lineStart = dart.notNull(i) + 1;
           lastWasCR = true;
         }
       }
       if (dart.notNull(lineNum) > 1) {
-        report = ` (at line ${lineNum}, character ${dart.notNull(offset) - dart.notNull(lineStart) + 1})\n`;
+        report = String['+'](report, ` (at line ${lineNum}, character ${dart.notNull(offset) - dart.notNull(lineStart) + 1})\n`);
       } else {
-        report = ` (at character ${dart.notNull(offset) + 1})\n`;
+        report = String['+'](report, ` (at character ${dart.notNull(offset) + 1})\n`);
       }
       let lineEnd = dart.as(dart.dload(this.source, 'length'), int);
       for (let i = offset; i['<'](dart.dload(this.source, 'length')); i = dart.notNull(i) + 1) {
         let char = dart.as(dart.dinvoke(this.source, 'codeUnitAt', i), int);
         if (char == 10 || char == 13) {
           lineEnd = i;
           break;
         }
       }
       let length = dart.notNull(lineEnd) - dart.notNull(lineStart);
@@ skipping 51 matching lines @@
         let values = _js_helper.Primitives.getProperty(object, Expando[_EXPANDO_PROPERTY_NAME]);
         if (values == null) {
           values = new Object();
           _js_helper.Primitives.setProperty(object, Expando[_EXPANDO_PROPERTY_NAME], values);
         }
         _js_helper.Primitives.setProperty(values, this[_getKey](), value);
       }
       [_getKey]() {
         let key = dart.as(_js_helper.Primitives.getProperty(this, Expando[_KEY_PROPERTY_NAME]), String);
         if (key == null) {
-          key = `expando$key$${((x) => Expando[_keyCount] = dart.notNull(x) + 1, x)(Expando[_keyCount])}`;
+          key = `expando$key$${(() => {
+            let x = Expando[_keyCount];
+            Expando[_keyCount] = dart.notNull(x) + 1;
+            return x;
+          })()}`;
           _js_helper.Primitives.setProperty(this, Expando[_KEY_PROPERTY_NAME], key);
         }
         return key;
       }
     }
     Expando._KEY_PROPERTY_NAME = 'expando$key';
     Expando._EXPANDO_PROPERTY_NAME = 'expando$values';
     Expando._keyCount = 0;
     return Expando;
   });
@@ skipping 175 matching lines @@
         return dart.as(result, List$(E));
       }
       from(elements, opts) {
         let growable = opts && 'growable' in opts ? opts.growable : true;
         return null;
       }
       generate(length, generator, opts) {
         let growable = opts && 'growable' in opts ? opts.growable : true;
         let result = null;
         if (growable) {
-          result = ((_$) => {
-            _$[exports.$length] = length;
-            return _$;
-          })(new List$(E).from([]));
+          result = new List$(E).from([]);
+          result[exports.$length] = length;
         } else {
           result = new (List$(E))(length);
         }
         for (let i = 0; dart.notNull(i) < dart.notNull(length); i = dart.notNull(i) + 1) {
           result[exports.$set](i, generator(i));
         }
         return result;
       }
     }
     List[dart.implements] = () => [Iterable$(E), _internal.EfficientLength];
@@ skipping 789 matching lines @@
     static get base() {
       let uri = _js_helper.Primitives.currentUri();
       if (uri != null)
         return Uri.parse(uri);
       throw new UnsupportedError("'Uri.base' is not supported");
     }
     static get [_isWindows]() {
       return false;
     }
     static [_checkNonWindowsPathReservedCharacters](segments, argumentError) {
-      segments[exports.$forEach](dart.as((segment) => {
+      segments[exports.$forEach](dart.as(segment => {
         if (dart.dinvoke(segment, 'contains', "/")) {
           if (argumentError) {
             throw new ArgumentError(`Illegal path character ${segment}`);
           } else {
             throw new UnsupportedError(`Illegal path character ${segment}`);
           }
         }
       }, dart.throw_("Unimplemented type (String) → void")));
     }
     static [_checkWindowsPathReservedCharacters](segments, argumentError, firstSegment) {
       if (firstSegment === void 0)
         firstSegment = 0;
-      segments[exports.$skip](firstSegment)[exports.$forEach](dart.as((segment) => {
+      segments[exports.$skip](firstSegment)[exports.$forEach](dart.as(segment => {
         if (dart.dinvoke(segment, 'contains', new RegExp('["*/:<>?\\\\|]'))) {
           if (argumentError) {
             throw new ArgumentError("Illegal character in path");
           } else {
             throw new UnsupportedError("Illegal character in path");
           }
         }
       }, dart.throw_("Unimplemented type (String) → void")));
     }
     static [_checkWindowsDriveLetter](charCode, argumentError) {
@@ skipping 161 matching lines @@
     static [_normalizeRegName](host, start, end) {
       let buffer = null;
       let sectionStart = start;
       let index = start;
       let isNormalized = true;
       while (dart.notNull(index) < dart.notNull(end)) {
         let char = host.codeUnitAt(index);
         if (char == Uri[_PERCENT]) {
           let replacement = Uri[_normalizeEscape](host, index, true);
           if (dart.notNull(replacement == null) && dart.notNull(isNormalized)) {
-            index = 3;
+            index = dart.notNull(index) + 3;
             continue;
           }
           if (buffer == null)
             buffer = new StringBuffer();
           let slice = host.substring(sectionStart, index);
           if (!dart.notNull(isNormalized))
             slice = slice.toLowerCase();
           buffer.write(slice);
           let sourceLength = 3;
           if (replacement == null) {
             replacement = host.substring(index, dart.notNull(index) + 3);
           } else if (replacement == "%") {
             replacement = "%25";
             sourceLength = 1;
           }
           buffer.write(replacement);
-          index = sourceLength;
+          index = dart.notNull(index) + dart.notNull(sourceLength);
           sectionStart = index;
           isNormalized = true;
         } else if (Uri[_isRegNameChar](char)) {
           if (dart.notNull(isNormalized) && dart.notNull(Uri[_UPPER_CASE_A]) <= dart.notNull(char) && dart.notNull(Uri[_UPPER_CASE_Z]) >= dart.notNull(char)) {
             if (buffer == null)
               buffer = new StringBuffer();
             if (dart.notNull(sectionStart) < dart.notNull(index)) {
               buffer.write(host.substring(sectionStart, index));
               sectionStart = index;
             }
@@ skipping 11 matching lines @@
               sourceLength = 2;
             }
           }
           if (buffer == null)
             buffer = new StringBuffer();
           let slice = host.substring(sectionStart, index);
           if (!dart.notNull(isNormalized))
             slice = slice.toLowerCase();
           buffer.write(slice);
           buffer.write(Uri[_escapeChar](char));
-          index = sourceLength;
+          index = dart.notNull(index) + dart.notNull(sourceLength);
           sectionStart = index;
         }
       }
       if (buffer == null)
         return host.substring(start, end);
       if (dart.notNull(sectionStart) < dart.notNull(end)) {
         let slice = host.substring(sectionStart, end);
         if (!dart.notNull(isNormalized))
           slice = slice.toLowerCase();
         buffer.write(slice);
@@ skipping 30 matching lines @@
     static [_makePath](path, start, end, pathSegments, ensureLeadingSlash, isFile) {
       if (dart.notNull(path == null) && dart.notNull(pathSegments == null))
         return isFile ? "/" : "";
       if (dart.notNull(path != null) && dart.notNull(pathSegments != null)) {
         throw new ArgumentError('Both path and pathSegments specified');
       }
       let result = null;
       if (path != null) {
         result = Uri[_normalize](path, start, end, dart.as(Uri[_pathCharOrSlashTable], List$(int)));
       } else {
-        result = pathSegments[exports.$map](dart.as((s) => Uri[_uriEncode](dart.as(Uri[_pathCharTable], List$(int)), dart.as(s, String)), dart.throw_("Unimplemented type (String) → dynamic")))[exports.$join]("/");
+        result = pathSegments[exports.$map](dart.as(s => Uri[_uriEncode](dart.as(Uri[_pathCharTable], List$(int)), dart.as(s, String)), dart.throw_("Unimplemented type (String) → dynamic")))[exports.$join]("/");
       }
       if (dart.dload(result, 'isEmpty')) {
         if (isFile)
           return "/";
       } else if ((dart.notNull(isFile) || dart.notNull(ensureLeadingSlash)) && dart.notNull(!dart.equals(dart.dinvoke(result, 'codeUnitAt', 0), Uri[_SLASH]))) {
         return `/${result}`;
       }
       return dart.as(result, String);
     }
     static [_makeQuery](query, start, end, queryParameters) {
@@ skipping 23 matching lines @@
       if (fragment == null)
         return null;
       return Uri[_normalize](fragment, start, end, dart.as(Uri[_queryCharTable], List$(int)));
     }
     static [_stringOrNullLength](s) {
       return s == null ? 0 : s.length;
     }
     static [_isHexDigit](char) {
       if (dart.notNull(Uri[_NINE]) >= dart.notNull(char))
         return dart.notNull(Uri[_ZERO]) <= dart.notNull(char);
-      char = 32;
+      char = dart.notNull(char) | 32;
       return dart.notNull(Uri[_LOWER_CASE_A]) <= dart.notNull(char) && dart.notNull(Uri[_LOWER_CASE_F]) >= dart.notNull(char);
     }
     static [_hexValue](char) {
       dart.assert(Uri[_isHexDigit](char));
       if (dart.notNull(Uri[_NINE]) >= dart.notNull(char))
         return dart.notNull(char) - dart.notNull(Uri[_ZERO]);
-      char = 32;
+      char = dart.notNull(char) | 32;
       return dart.notNull(char) - (dart.notNull(Uri[_LOWER_CASE_A]) - 10);
     }
     static [_normalizeEscape](source, index, lowerCase) {
       dart.assert(source.codeUnitAt(index) == Uri[_PERCENT]);
       if (dart.notNull(index) + 2 >= dart.notNull(source.length)) {
         return "%";
       }
       let firstDigit = source.codeUnitAt(dart.notNull(index) + 1);
       let secondDigit = source.codeUnitAt(dart.notNull(index) + 2);
       if (!dart.notNull(Uri[_isHexDigit](firstDigit)) || !dart.notNull(Uri[_isHexDigit](secondDigit))) {
         return "%";
       }
       let value = dart.notNull(Uri[_hexValue](firstDigit)) * 16 + dart.notNull(Uri[_hexValue](secondDigit));
       if (Uri[_isUnreservedChar](value)) {
         if (dart.notNull(lowerCase) && dart.notNull(Uri[_UPPER_CASE_A]) <= dart.notNull(value) && dart.notNull(Uri[_UPPER_CASE_Z]) >= dart.notNull(value)) {
-          value = 32;
+          value = dart.notNull(value) | 32;
         }
         return new String.fromCharCode(value);
       }
       if (dart.notNull(firstDigit) >= dart.notNull(Uri[_LOWER_CASE_A]) || dart.notNull(secondDigit) >= dart.notNull(Uri[_LOWER_CASE_A])) {
         return source.substring(index, dart.notNull(index) + 3).toUpperCase();
       }
       return null;
     }
     static [_isUnreservedChar](ch) {
       return dart.notNull(ch) < 127 && dart.notNull(!dart.equals(dart.dbinary(Uri[_unreservedTable][exports.$get](dart.notNull(ch) >> 4), '&', 1 << (dart.notNull(ch) & 15)), 0));
@@ skipping 18 matching lines @@
             flag = 240;
           }
         }
         codeUnits = new List(3 * dart.notNull(encodedBytes));
         let index = 0;
         while ((encodedBytes = dart.notNull(encodedBytes) - 1) >= 0) {
           let byte = dart.as(dart.dbinary(dart.dbinary(dart.dbinary(char, '>>', 6 * dart.notNull(encodedBytes)), '&', 63), '|', flag), int);
           codeUnits[exports.$set](index, Uri[_PERCENT]);
           codeUnits[exports.$set](dart.notNull(index) + 1, hexDigits.codeUnitAt(dart.notNull(byte) >> 4));
           codeUnits[exports.$set](dart.notNull(index) + 2, hexDigits.codeUnitAt(dart.notNull(byte) & 15));
-          index = 3;
+          index = dart.notNull(index) + 3;
           flag = 128;
         }
       }
       return new String.fromCharCodes(dart.as(codeUnits, Iterable$(int)));
     }
     static [_normalize](component, start, end, charTable) {
       let buffer = null;
       let sectionStart = start;
       let index = start;
       while (dart.notNull(index) < dart.notNull(end)) {
         let char = component.codeUnitAt(index);
         if (dart.notNull(char) < 127 && (dart.notNull(charTable[exports.$get](dart.notNull(char) >> 4)) & 1 << (dart.notNull(char) & 15)) != 0) {
           index = dart.notNull(index) + 1;
         } else {
           let replacement = null;
           let sourceLength = null;
           if (char == Uri[_PERCENT]) {
             replacement = Uri[_normalizeEscape](component, index, false);
             if (replacement == null) {
-              index = 3;
+              index = dart.notNull(index) + 3;
               continue;
             }
             if ("%" == replacement) {
               replacement = "%25";
               sourceLength = 1;
             } else {
               sourceLength = 3;
             }
           } else if (Uri[_isGeneralDelimiter](char)) {
             Uri[_fail](component, index, "Invalid character");
           } else {
             sourceLength = 1;
             if ((dart.notNull(char) & 64512) == 55296) {
               if (dart.notNull(index) + 1 < dart.notNull(end)) {
                 let tail = component.codeUnitAt(dart.notNull(index) + 1);
                 if ((dart.notNull(tail) & 64512) == 56320) {
                   sourceLength = 2;
                   char = 65536 | (dart.notNull(char) & 1023) << 10 | dart.notNull(tail) & 1023;
                 }
               }
             }
             replacement = Uri[_escapeChar](char);
           }
           if (buffer == null)
             buffer = new StringBuffer();
           buffer.write(component.substring(sectionStart, index));
           buffer.write(replacement);
-          index = sourceLength;
+          index = dart.notNull(index) + dart.notNull(sourceLength);
           sectionStart = index;
         }
       }
       if (buffer == null) {
         return component.substring(start, end);
       }
       if (dart.notNull(sectionStart) < dart.notNull(end)) {
         buffer.write(component.substring(sectionStart, end));
       }
       return buffer.toString();
     }
     static [_isSchemeCharacter](ch) {
       return dart.notNull(ch) < 128 && dart.notNull(!dart.equals(dart.dbinary(Uri[_schemeTable][exports.$get](dart.notNull(ch) >> 4), '&', 1 << (dart.notNull(ch) & 15)), 0));
     }
     static [_isGeneralDelimiter](ch) {
       return dart.notNull(ch) <= dart.notNull(Uri[_RIGHT_BRACKET]) && dart.notNull(!dart.equals(dart.dbinary(Uri[_genDelimitersTable][exports.$get](dart.notNull(ch) >> 4), '&', 1 << (dart.notNull(ch) & 15)), 0));
     }
     get isAbsolute() {
       return dart.notNull(this.scheme != "") && dart.notNull(this.fragment == "");
     }
     [_merge](base, reference) {
       if (base.isEmpty)
         return `/${reference}`;
       let backCount = 0;
       let refStart = 0;
       while (reference.startsWith("../", refStart)) {
-        refStart = 3;
+        refStart = dart.notNull(refStart) + 3;
         backCount = dart.notNull(backCount) + 1;
       }
       let baseEnd = base.lastIndexOf('/');
       while (dart.notNull(baseEnd) > 0 && dart.notNull(backCount) > 0) {
         let newEnd = base.lastIndexOf('/', dart.notNull(baseEnd) - 1);
         if (dart.notNull(newEnd) < 0) {
           break;
         }
         let delta = dart.notNull(baseEnd) - dart.notNull(newEnd);
         if ((delta == 2 || delta == 3) && base.codeUnitAt(dart.notNull(newEnd) + 1) == Uri[_DOT] && (delta == 2 || base.codeUnitAt(dart.notNull(newEnd) + 2) == Uri[_DOT])) {
@@ skipping 250 matching lines @@
     }
     static parseIPv4Address(host) {
       // Function error: (String) → void
       function error(msg) {
         throw new FormatException(`Illegal IPv4 address, ${msg}`);
       }
       let bytes = host.split('.');
       if (bytes[exports.$length] != 4) {
         error('IPv4 address should contain exactly 4 parts');
       }
-      return dart.as(bytes[exports.$map](dart.as((byteString) => {
+      return dart.as(bytes[exports.$map](dart.as(byteString => {
         let byte = int.parse(dart.as(byteString, String));
         if (dart.notNull(byte) < 0 || dart.notNull(byte) > 255) {
           error('each part must be in the range of `0..255`');
         }
         return byte;
       }, dart.throw_("Unimplemented type (String) → dynamic")))[exports.$toList](), List$(int));
     }
     static parseIPv6Address(host, start, end) {
       if (start === void 0)
         start = 0;
@@ skipping 74 matching lines @@
         error('an address without a wildcard must contain exactly 8 parts');
       }
       let bytes = new (List$(int))(16);
       for (let i = 0, index = 0; dart.notNull(i) < dart.notNull(parts[exports.$length]); i = dart.notNull(i) + 1) {
         let value = parts[exports.$get](i);
         if (value == -1) {
           let wildCardLength = 9 - dart.notNull(parts[exports.$length]);
           for (let j = 0; dart.notNull(j) < dart.notNull(wildCardLength); j = dart.notNull(j) + 1) {
             bytes[exports.$set](index, 0);
             bytes[exports.$set](dart.notNull(index) + 1, 0);
-            index = 2;
+            index = dart.notNull(index) + 2;
           }
         } else {
           bytes[exports.$set](index, dart.notNull(value) >> 8);
           bytes[exports.$set](dart.notNull(index) + 1, dart.notNull(value) & 255);
-          index = 2;
+          index = dart.notNull(index) + 2;
         }
       }
       return dart.as(bytes, List$(int));
     }
     static [_uriEncode](canonicalTable, text, opts) {
       let encoding = opts && 'encoding' in opts ? opts.encoding : convert.UTF8;
       let spaceToPlus = opts && 'spaceToPlus' in opts ? opts.spaceToPlus : false;
       // Function byteToHex: (dynamic, dynamic) → dynamic
       function byteToHex(byte, buffer) {
         let hex = '0123456789ABCDEF';
@@ skipping 15 matching lines @@
       }
       return result.toString();
     }
     static [_hexCharPairToByte](s, pos) {
       let byte = 0;
       for (let i = 0; dart.notNull(i) < 2; i = dart.notNull(i) + 1) {
         let charCode = s.codeUnitAt(dart.notNull(pos) + dart.notNull(i));
         if (48 <= dart.notNull(charCode) && dart.notNull(charCode) <= 57) {
           byte = dart.notNull(byte) * 16 + dart.notNull(charCode) - 48;
         } else {
-          charCode = 32;
+          charCode = dart.notNull(charCode) | 32;
           if (97 <= dart.notNull(charCode) && dart.notNull(charCode) <= 102) {
             byte = dart.notNull(byte) * 16 + dart.notNull(charCode) - 87;
           } else {
             throw new ArgumentError("Invalid URL encoding");
           }
         }
       }
       return byte;
     }
     static [_uriDecode](text, opts) {
@@ skipping 16 matching lines @@
         for (let i = 0; dart.notNull(i) < dart.notNull(text.length); i = dart.notNull(i) + 1) {
           let codeUnit = text.codeUnitAt(i);
           if (dart.notNull(codeUnit) > 127) {
             throw new ArgumentError("Illegal percent encoding in URI");
           }
           if (codeUnit == Uri[_PERCENT]) {
             if (dart.notNull(i) + 3 > dart.notNull(text.length)) {
               throw new ArgumentError('Truncated URI');
             }
             bytes[exports.$add](Uri[_hexCharPairToByte](text, dart.notNull(i) + 1));
-            i = 2;
+            i = dart.notNull(i) + 2;
           } else if (dart.notNull(plusToSpace) && codeUnit == Uri[_PLUS]) {
             bytes[exports.$add](Uri[_SPACE]);
           } else {
             bytes[exports.$add](codeUnit);
           }
         }
       }
       return encoding.decode(bytes);
     }
     static [_isAlphabeticCharacter](codeUnit) {
@@ skipping 132 matching lines @@
   exports.Stopwatch = Stopwatch;
   exports.String = String;
   exports.$last = $last;
   exports.RuneIterator = RuneIterator;
   exports.StringBuffer = StringBuffer;
   exports.StringSink = StringSink;
   exports.Symbol = Symbol;
   exports.Type = Type;
   exports.Uri = Uri;
 })(core || (core = {}));