diff --git a/lib/coffeescript/cake.js b/lib/coffeescript/cake.js
index b5334b7d6c..13fb0e7e06 100644
--- a/lib/coffeescript/cake.js
+++ b/lib/coffeescript/cake.js
@@ -24,15 +24,10 @@
 
   helpers.extend(global, {
     task: function(name, description, action) {
-      var ref;
       if (!action) {
-        ref = [description, action], action = ref[0], description = ref[1];
+        [action, description] = [description, action];
       }
-      return tasks[name] = {
-        name: name,
-        description: description,
-        action: action
-      };
+      return tasks[name] = {name, description, action};
     },
     option: function(letter, flag, description) {
       return switches.push([letter, flag, description]);
diff --git a/lib/coffeescript/coffeescript.js b/lib/coffeescript/coffeescript.js
index 66556ffd77..35f38ac13c 100644
--- a/lib/coffeescript/coffeescript.js
+++ b/lib/coffeescript/coffeescript.js
@@ -9,9 +9,9 @@
 
   path = require('path');
 
-  Lexer = require('./lexer').Lexer;
+  ({Lexer} = require('./lexer'));
 
-  parser = require('./parser').parser;
+  ({parser} = require('./parser'));
 
   helpers = require('./helpers');
 
@@ -59,7 +59,7 @@
 
   exports.compile = compile = withPrettyErrors(function(code, options) {
     var currentColumn, currentLine, encoded, extend, filename, fragment, fragments, generateSourceMap, header, i, j, js, len, len1, map, merge, newLines, ref, ref1, sourceMapDataURI, sourceURL, token, tokens, v3SourceMap;
-    merge = helpers.merge, extend = helpers.extend;
+    ({merge, extend} = helpers);
     options = extend({}, options);
     generateSourceMap = options.sourceMap || options.inlineMap || (options.filename == null);
     filename = options.filename || '<anonymous>';
@@ -132,7 +132,7 @@
     }
     if (options.sourceMap) {
       return {
-        js: js,
+        js,
         sourceMap: map,
         v3SourceMap: JSON.stringify(v3SourceMap, null, 2)
       };
@@ -254,9 +254,9 @@
     stripped = raw.charCodeAt(0) === 0xFEFF ? raw.substring(1) : raw;
     try {
       answer = compile(stripped, {
-        filename: filename,
-        sourceMap: sourceMap,
-        inlineMap: inlineMap,
+        filename,
+        sourceMap,
+        inlineMap,
         sourceFiles: [filename],
         literate: helpers.isLiterate(filename)
       });
@@ -274,7 +274,7 @@
       var tag, token;
       token = parser.tokens[this.pos++];
       if (token) {
-        tag = token[0], this.yytext = token[1], this.yylloc = token[2];
+        [tag, this.yytext, this.yylloc] = token;
         parser.errorToken = token.origin || token;
         this.yylineno = this.yylloc.first_line;
       } else {
@@ -295,9 +295,9 @@
 
   parser.yy.parseError = function(message, arg) {
     var errorLoc, errorTag, errorText, errorToken, token, tokens;
-    token = arg.token;
-    errorToken = parser.errorToken, tokens = parser.tokens;
-    errorTag = errorToken[0], errorText = errorToken[1], errorLoc = errorToken[2];
+    ({token} = arg);
+    ({errorToken, tokens} = parser);
+    [errorTag, errorText, errorLoc] = errorToken;
     errorText = (function() {
       switch (false) {
         case errorToken !== tokens[tokens.length - 1]:
diff --git a/lib/coffeescript/command.js b/lib/coffeescript/command.js
index 3bd6487dde..13478f4d86 100644
--- a/lib/coffeescript/command.js
+++ b/lib/coffeescript/command.js
@@ -1,6 +1,6 @@
 // Generated by CoffeeScript 2.0.0-alpha1
 (function() {
-  var BANNER, CoffeeScript, EventEmitter, SWITCHES, compileJoin, compileOptions, compilePath, compileScript, compileStdio, exec, findDirectoryIndex, forkNode, fs, helpers, hidden, joinTimeout, makePrelude, mkdirp, notSources, optionParser, optparse, opts, outputPath, parseOptions, path, printLine, printTokens, printWarn, ref, removeSource, removeSourceDir, silentUnlink, sourceCode, sources, spawn, timeLog, usage, useWinPathSep, version, wait, watch, watchDir, watchedDirs, writeJs,
+  var BANNER, CoffeeScript, EventEmitter, SWITCHES, compileJoin, compileOptions, compilePath, compileScript, compileStdio, exec, findDirectoryIndex, forkNode, fs, helpers, hidden, joinTimeout, makePrelude, mkdirp, notSources, optionParser, optparse, opts, outputPath, parseOptions, path, printLine, printTokens, printWarn, removeSource, removeSourceDir, silentUnlink, sourceCode, sources, spawn, timeLog, usage, useWinPathSep, version, wait, watch, watchDir, watchedDirs, writeJs,
     indexOf = [].indexOf || function(item) { for (var i = 0, l = this.length; i < l; i++) { if (i in this && this[i] === item) return i; } return -1; };
 
   fs = require('fs');
@@ -13,9 +13,9 @@
 
   CoffeeScript = require('./coffeescript');
 
-  ref = require('child_process'), spawn = ref.spawn, exec = ref.exec;
+  ({spawn, exec} = require('child_process'));
 
-  EventEmitter = require('events').EventEmitter;
+  ({EventEmitter} = require('events'));
 
   useWinPathSep = path.sep === '\\';
 
@@ -50,7 +50,7 @@
   optionParser = null;
 
   exports.run = function() {
-    var i, len, literals, ref1, replCliOpts, results, source;
+    var i, len, literals, ref, replCliOpts, results, source;
     parseOptions();
     replCliOpts = {
       useGlobal: true
@@ -90,10 +90,10 @@
       opts.join = path.resolve(opts.join);
       console.error('\nThe --join option is deprecated and will be removed in a future version.\n\nIf for some reason it\'s necessary to share local variables between files,\nreplace...\n\n    $ coffee --compile --join bundle.js -- a.coffee b.coffee c.coffee\n\nwith...\n\n    $ cat a.coffee b.coffee c.coffee | coffee --compile --stdio > bundle.js\n');
     }
-    ref1 = opts["arguments"];
+    ref = opts["arguments"];
     results = [];
-    for (i = 0, len = ref1.length; i < len; i++) {
-      source = ref1[i];
+    for (i = 0, len = ref.length; i < len; i++) {
+      source = ref[i];
       source = path.resolve(source);
       results.push(compilePath(source, true, source));
     }
@@ -104,7 +104,7 @@
     return requires.map(function(module) {
       var _, match, name;
       if (match = module.match(/^(.*)=(.*)$/)) {
-        _ = match[0], name = match[1], module = match[2];
+        [_, name, module] = match;
       }
       name || (name = helpers.baseFileName(module, true, useWinPathSep));
       return `${name} = require('${module}')`;
@@ -178,10 +178,10 @@
   };
 
   findDirectoryIndex = function(source) {
-    var err, ext, i, index, len, ref1;
-    ref1 = CoffeeScript.FILE_EXTENSIONS;
-    for (i = 0, len = ref1.length; i < len; i++) {
-      ext = ref1[i];
+    var err, ext, i, index, len, ref;
+    ref = CoffeeScript.FILE_EXTENSIONS;
+    for (i = 0, len = ref.length; i < len; i++) {
+      ext = ref[i];
       index = path.join(source, `index${ext}`);
       try {
         if ((fs.statSync(index)).isFile()) {
@@ -203,11 +203,7 @@
     o = opts;
     options = compileOptions(file, base);
     try {
-      t = task = {
-        file: file,
-        input: input,
-        options: options
-      };
+      t = task = {file, input, options};
       CoffeeScript.emit('compile', task);
       if (o.tokens) {
         return printTokens(CoffeeScript.tokens(t.input, t.options));
@@ -425,12 +421,12 @@
   };
 
   silentUnlink = function(path) {
-    var err, ref1;
+    var err, ref;
     try {
       return fs.unlinkSync(path);
     } catch (error) {
       err = error;
-      if ((ref1 = err.code) !== 'ENOENT' && ref1 !== 'EPERM') {
+      if ((ref = err.code) !== 'ENOENT' && ref !== 'EPERM') {
         throw err;
       }
     }
@@ -546,7 +542,7 @@
   compileOptions = function(filename, base) {
     var answer, cwd, jsDir, jsPath;
     answer = {
-      filename: filename,
+      filename,
       literate: opts.literate || helpers.isLiterate(filename),
       bare: opts.bare,
       header: opts.compile && !opts['no-header'],
@@ -559,7 +555,7 @@
         jsPath = outputPath(filename, base);
         jsDir = path.dirname(jsPath);
         answer = helpers.merge(answer, {
-          jsPath: jsPath,
+          jsPath,
           sourceRoot: path.relative(jsDir, cwd),
           sourceFiles: [path.relative(cwd, filename)],
           generatedFile: helpers.baseFileName(jsPath, false, useWinPathSep)
diff --git a/lib/coffeescript/grammar.js b/lib/coffeescript/grammar.js
index c47943faac..f778dbb5b3 100644
--- a/lib/coffeescript/grammar.js
+++ b/lib/coffeescript/grammar.js
@@ -2,7 +2,7 @@
 (function() {
   var Parser, alt, alternatives, grammar, name, o, operators, token, tokens, unwrap;
 
-  Parser = require('jison').Parser;
+  ({Parser} = require('jison'));
 
   unwrap = /^function\s*\(\)\s*\{\s*return\s*([\s\S]*);\s*\}/;
 
diff --git a/lib/coffeescript/helpers.js b/lib/coffeescript/helpers.js
index 7027a43f99..134a74dbcb 100644
--- a/lib/coffeescript/helpers.js
+++ b/lib/coffeescript/helpers.js
@@ -197,11 +197,11 @@
   };
 
   syntaxErrorToString = function() {
-    var codeLine, colorize, colorsEnabled, end, filename, first_column, first_line, last_column, last_line, marker, ref1, ref2, ref3, ref4, start;
+    var codeLine, colorize, colorsEnabled, end, filename, first_column, first_line, last_column, last_line, marker, ref1, ref2, ref3, start;
     if (!(this.code && this.location)) {
       return Error.prototype.toString.call(this);
     }
-    ref1 = this.location, first_line = ref1.first_line, first_column = ref1.first_column, last_line = ref1.last_line, last_column = ref1.last_column;
+    ({first_line, first_column, last_line, last_column} = this.location);
     if (last_line == null) {
       last_line = first_line;
     }
@@ -214,9 +214,9 @@
     end = first_line === last_line ? last_column + 1 : codeLine.length;
     marker = codeLine.slice(0, start).replace(/[^\s]/g, ' ') + repeat('^', end - start);
     if (typeof process !== "undefined" && process !== null) {
-      colorsEnabled = ((ref2 = process.stdout) != null ? ref2.isTTY : void 0) && !((ref3 = process.env) != null ? ref3.NODE_DISABLE_COLORS : void 0);
+      colorsEnabled = ((ref1 = process.stdout) != null ? ref1.isTTY : void 0) && !((ref2 = process.env) != null ? ref2.NODE_DISABLE_COLORS : void 0);
     }
-    if ((ref4 = this.colorful) != null ? ref4 : colorsEnabled) {
+    if ((ref3 = this.colorful) != null ? ref3 : colorsEnabled) {
       colorize = function(str) {
         return `\x1B[1;31m${str}\x1B[0m`;
       };
diff --git a/lib/coffeescript/lexer.js b/lib/coffeescript/lexer.js
index cd97d9f9bf..b91efc1c1b 100644
--- a/lib/coffeescript/lexer.js
+++ b/lib/coffeescript/lexer.js
@@ -1,15 +1,15 @@
 // Generated by CoffeeScript 2.0.0-alpha1
 (function() {
-  var BOM, BOOL, CALLABLE, CODE, COFFEE_ALIASES, COFFEE_ALIAS_MAP, COFFEE_KEYWORDS, COMMENT, COMPARE, COMPOUND_ASSIGN, HERECOMMENT_ILLEGAL, HEREDOC_DOUBLE, HEREDOC_INDENT, HEREDOC_SINGLE, HEREGEX, HEREGEX_OMIT, HERE_JSTOKEN, IDENTIFIER, INDENTABLE_CLOSERS, INDEXABLE, INVALID_ESCAPE, INVERSES, JSTOKEN, JS_KEYWORDS, LEADING_BLANK_LINE, LINE_BREAK, LINE_CONTINUER, Lexer, MATH, MULTI_DENT, NOT_REGEX, NUMBER, OPERATOR, POSSIBLY_DIVISION, REGEX, REGEX_FLAGS, REGEX_ILLEGAL, RELATION, RESERVED, Rewriter, SHIFT, SIMPLE_STRING_OMIT, STRICT_PROSCRIBED, STRING_DOUBLE, STRING_OMIT, STRING_SINGLE, STRING_START, TRAILING_BLANK_LINE, TRAILING_SPACES, UNARY, UNARY_MATH, VALID_FLAGS, WHITESPACE, compact, count, invertLiterate, isForFrom, isUnassignable, key, locationDataToString, ref, ref1, repeat, starts, throwSyntaxError,
+  var BOM, BOOL, CALLABLE, CODE, COFFEE_ALIASES, COFFEE_ALIAS_MAP, COFFEE_KEYWORDS, COMMENT, COMPARE, COMPOUND_ASSIGN, HERECOMMENT_ILLEGAL, HEREDOC_DOUBLE, HEREDOC_INDENT, HEREDOC_SINGLE, HEREGEX, HEREGEX_OMIT, HERE_JSTOKEN, IDENTIFIER, INDENTABLE_CLOSERS, INDEXABLE, INVALID_ESCAPE, INVERSES, JSTOKEN, JS_KEYWORDS, LEADING_BLANK_LINE, LINE_BREAK, LINE_CONTINUER, Lexer, MATH, MULTI_DENT, NOT_REGEX, NUMBER, OPERATOR, POSSIBLY_DIVISION, REGEX, REGEX_FLAGS, REGEX_ILLEGAL, RELATION, RESERVED, Rewriter, SHIFT, SIMPLE_STRING_OMIT, STRICT_PROSCRIBED, STRING_DOUBLE, STRING_OMIT, STRING_SINGLE, STRING_START, TRAILING_BLANK_LINE, TRAILING_SPACES, UNARY, UNARY_MATH, VALID_FLAGS, WHITESPACE, compact, count, invertLiterate, isForFrom, isUnassignable, key, locationDataToString, repeat, starts, throwSyntaxError,
     indexOf = [].indexOf || function(item) { for (var i = 0, l = this.length; i < l; i++) { if (i in this && this[i] === item) return i; } return -1; };
 
-  ref = require('./rewriter'), Rewriter = ref.Rewriter, INVERSES = ref.INVERSES;
+  ({Rewriter, INVERSES} = require('./rewriter'));
 
-  ref1 = require('./helpers'), count = ref1.count, starts = ref1.starts, compact = ref1.compact, repeat = ref1.repeat, invertLiterate = ref1.invertLiterate, locationDataToString = ref1.locationDataToString, throwSyntaxError = ref1.throwSyntaxError;
+  ({count, starts, compact, repeat, invertLiterate, locationDataToString, throwSyntaxError} = require('./helpers'));
 
   exports.Lexer = Lexer = class Lexer {
     tokenize(code, opts = {}) {
-      var consumed, end, i, ref2;
+      var consumed, end, i;
       this.literate = opts.literate;
       this.indent = 0;
       this.baseIndent = 0;
@@ -29,7 +29,7 @@
       i = 0;
       while (this.chunk = code.slice(i)) {
         consumed = this.identifierToken() || this.commentToken() || this.whitespaceToken() || this.lineToken() || this.stringToken() || this.numberToken() || this.regexToken() || this.jsToken() || this.literalToken();
-        ref2 = this.getLineAndColumnFromChunk(consumed), this.chunkLine = ref2[0], this.chunkColumn = ref2[1];
+        [this.chunkLine, this.chunkColumn] = this.getLineAndColumnFromChunk(consumed);
         i += consumed;
         if (opts.untilBalanced && this.ends.length === 0) {
           return {
@@ -64,11 +64,11 @@
     }
 
     identifierToken() {
-      var alias, colon, colonOffset, id, idLength, input, match, poppedToken, prev, ref2, ref3, ref4, ref5, ref6, ref7, tag, tagToken;
+      var alias, colon, colonOffset, id, idLength, input, match, poppedToken, prev, ref, ref1, ref2, ref3, ref4, tag, tagToken;
       if (!(match = IDENTIFIER.exec(this.chunk))) {
         return 0;
       }
-      input = match[0], id = match[1], colon = match[2];
+      [input, id, colon] = match;
       idLength = id.length;
       poppedToken = void 0;
       if (id === 'own' && this.tag() === 'FOR') {
@@ -82,10 +82,10 @@
       if (id === 'as' && this.seenImport) {
         if (this.value() === '*') {
           this.tokens[this.tokens.length - 1][0] = 'IMPORT_ALL';
-        } else if (ref2 = this.value(), indexOf.call(COFFEE_KEYWORDS, ref2) >= 0) {
+        } else if (ref = this.value(), indexOf.call(COFFEE_KEYWORDS, ref) >= 0) {
           this.tokens[this.tokens.length - 1][0] = 'IDENTIFIER';
         }
-        if ((ref3 = this.tag()) === 'DEFAULT' || ref3 === 'IMPORT_ALL' || ref3 === 'IDENTIFIER') {
+        if ((ref1 = this.tag()) === 'DEFAULT' || ref1 === 'IMPORT_ALL' || ref1 === 'IDENTIFIER') {
           this.token('AS', id);
           return id.length;
         }
@@ -98,11 +98,11 @@
         this.token('DEFAULT', id);
         return id.length;
       }
-      ref4 = this.tokens, prev = ref4[ref4.length - 1];
-      tag = colon || (prev != null) && (((ref5 = prev[0]) === '.' || ref5 === '?.' || ref5 === '::' || ref5 === '?::') || !prev.spaced && prev[0] === '@') ? 'PROPERTY' : 'IDENTIFIER';
+      ref2 = this.tokens, prev = ref2[ref2.length - 1];
+      tag = colon || (prev != null) && (((ref3 = prev[0]) === '.' || ref3 === '?.' || ref3 === '::' || ref3 === '?::') || !prev.spaced && prev[0] === '@') ? 'PROPERTY' : 'IDENTIFIER';
       if (tag === 'IDENTIFIER' && (indexOf.call(JS_KEYWORDS, id) >= 0 || indexOf.call(COFFEE_KEYWORDS, id) >= 0) && !(this.exportSpecifierList && indexOf.call(COFFEE_KEYWORDS, id) >= 0)) {
         tag = id.toUpperCase();
-        if (tag === 'WHEN' && (ref6 = this.tag(), indexOf.call(LINE_BREAK, ref6) >= 0)) {
+        if (tag === 'WHEN' && (ref4 = this.tag(), indexOf.call(LINE_BREAK, ref4) >= 0)) {
           tag = 'LEADING_WHEN';
         } else if (tag === 'FOR') {
           this.seenFor = true;
@@ -167,7 +167,7 @@
         tagToken.origin = [tag, alias, tagToken[2]];
       }
       if (poppedToken) {
-        ref7 = [poppedToken[2].first_line, poppedToken[2].first_column], tagToken[2].first_line = ref7[0], tagToken[2].first_column = ref7[1];
+        [tagToken[2].first_line, tagToken[2].first_column] = [poppedToken[2].first_line, poppedToken[2].first_column];
       }
       if (colon) {
         colonOffset = input.lastIndexOf(':');
@@ -223,8 +223,8 @@
     }
 
     stringToken() {
-      var $, attempt, delimiter, doc, end, heredoc, i, indent, indentRegex, match, quote, ref2, ref3, regex, token, tokens;
-      quote = (STRING_START.exec(this.chunk) || [])[0];
+      var $, attempt, delimiter, doc, end, heredoc, i, indent, indentRegex, match, quote, ref, regex, token, tokens;
+      [quote] = STRING_START.exec(this.chunk) || [];
       if (!quote) {
         return 0;
       }
@@ -244,7 +244,10 @@
         }
       })();
       heredoc = quote.length === 3;
-      ref2 = this.matchWithInterpolations(regex, quote), tokens = ref2.tokens, end = ref2.index;
+      ({
+        tokens,
+        index: end
+      } = this.matchWithInterpolations(regex, quote));
       $ = tokens.length - 1;
       delimiter = quote.charAt(0);
       if (heredoc) {
@@ -262,16 +265,14 @@
         })()).join('#{}');
         while (match = HEREDOC_INDENT.exec(doc)) {
           attempt = match[1];
-          if (indent === null || (0 < (ref3 = attempt.length) && ref3 < indent.length)) {
+          if (indent === null || (0 < (ref = attempt.length) && ref < indent.length)) {
             indent = attempt;
           }
         }
         if (indent) {
           indentRegex = RegExp(`\\n${indent}`, "g");
         }
-        this.mergeInterpolationTokens(tokens, {
-          delimiter: delimiter
-        }, (value, i) => {
+        this.mergeInterpolationTokens(tokens, {delimiter}, (value, i) => {
           value = this.formatString(value);
           if (indentRegex) {
             value = value.replace(indentRegex, '\n');
@@ -285,9 +286,7 @@
           return value;
         });
       } else {
-        this.mergeInterpolationTokens(tokens, {
-          delimiter: delimiter
-        }, (value, i) => {
+        this.mergeInterpolationTokens(tokens, {delimiter}, (value, i) => {
           value = this.formatString(value);
           value = value.replace(SIMPLE_STRING_OMIT, function(match, offset) {
             if ((i === 0 && offset === 0) || (i === $ && offset + match.length === value.length)) {
@@ -307,7 +306,7 @@
       if (!(match = this.chunk.match(COMMENT))) {
         return 0;
       }
-      comment = match[0], here = match[1];
+      [comment, here] = match;
       if (here) {
         if (match = HERECOMMENT_ILLEGAL.exec(comment)) {
           this.error(`block comments cannot contain ${match[0]}`, {
@@ -336,7 +335,7 @@
     }
 
     regexToken() {
-      var body, closed, end, flags, index, match, origin, prev, ref2, ref3, ref4, regex, tokens;
+      var body, closed, end, flags, index, match, origin, prev, ref, ref1, ref2, regex, tokens;
       switch (false) {
         case !(match = REGEX_ILLEGAL.exec(this.chunk)):
           this.error(`regular expressions cannot begin with ${match[2]}`, {
@@ -344,22 +343,22 @@
           });
           break;
         case !(match = this.matchWithInterpolations(HEREGEX, '///')):
-          tokens = match.tokens, index = match.index;
+          ({tokens, index} = match);
           break;
         case !(match = REGEX.exec(this.chunk)):
-          regex = match[0], body = match[1], closed = match[2];
+          [regex, body, closed] = match;
           this.validateEscapes(body, {
             isRegex: true,
             offsetInChunk: 1
           });
           index = regex.length;
-          ref2 = this.tokens, prev = ref2[ref2.length - 1];
+          ref = this.tokens, prev = ref[ref.length - 1];
           if (prev) {
-            if (prev.spaced && (ref3 = prev[0], indexOf.call(CALLABLE, ref3) >= 0)) {
+            if (prev.spaced && (ref1 = prev[0], indexOf.call(CALLABLE, ref1) >= 0)) {
               if (!closed || POSSIBLY_DIVISION.test(regex)) {
                 return 0;
               }
-            } else if (ref4 = prev[0], indexOf.call(NOT_REGEX, ref4) >= 0) {
+            } else if (ref2 = prev[0], indexOf.call(NOT_REGEX, ref2) >= 0) {
               return 0;
             }
           }
@@ -370,7 +369,7 @@
         default:
           return 0;
       }
-      flags = REGEX_FLAGS.exec(this.chunk.slice(index))[0];
+      [flags] = REGEX_FLAGS.exec(this.chunk.slice(index));
       end = index + flags.length;
       origin = this.makeToken('REGEX', null, 0, end);
       switch (false) {
@@ -469,7 +468,7 @@
     }
 
     outdentToken(moveOut, noNewlines, outdentLength) {
-      var decreasedIndent, dent, lastIndent, ref2;
+      var decreasedIndent, dent, lastIndent, ref;
       decreasedIndent = this.indent - moveOut;
       while (moveOut > 0) {
         lastIndent = this.indents[this.indents.length - 1];
@@ -483,7 +482,7 @@
           moveOut -= lastIndent;
         } else {
           dent = this.indents.pop() + this.outdebt;
-          if (outdentLength && (ref2 = this.chunk[outdentLength], indexOf.call(INDENTABLE_CLOSERS, ref2) >= 0)) {
+          if (outdentLength && (ref = this.chunk[outdentLength], indexOf.call(INDENTABLE_CLOSERS, ref) >= 0)) {
             decreasedIndent -= dent - moveOut;
             moveOut = dent;
           }
@@ -508,11 +507,11 @@
     }
 
     whitespaceToken() {
-      var match, nline, prev, ref2;
+      var match, nline, prev, ref;
       if (!((match = WHITESPACE.exec(this.chunk)) || (nline = this.chunk.charAt(0) === '\n'))) {
         return 0;
       }
-      ref2 = this.tokens, prev = ref2[ref2.length - 1];
+      ref = this.tokens, prev = ref[ref.length - 1];
       if (prev) {
         prev[match ? 'spaced' : 'newLine'] = true;
       }
@@ -541,9 +540,9 @@
     }
 
     literalToken() {
-      var match, message, origin, prev, ref2, ref3, ref4, ref5, ref6, skipToken, tag, token, value;
+      var match, message, origin, prev, ref, ref1, ref2, ref3, ref4, skipToken, tag, token, value;
       if (match = OPERATOR.exec(this.chunk)) {
-        value = match[0];
+        [value] = match;
         if (CODE.test(value)) {
           this.tagParameters();
         }
@@ -551,17 +550,17 @@
         value = this.chunk.charAt(0);
       }
       tag = value;
-      ref2 = this.tokens, prev = ref2[ref2.length - 1];
+      ref = this.tokens, prev = ref[ref.length - 1];
       if (prev && indexOf.call(['=', ...COMPOUND_ASSIGN], value) >= 0) {
         skipToken = false;
-        if (value === '=' && ((ref3 = prev[1]) === '||' || ref3 === '&&') && !prev.spaced) {
+        if (value === '=' && ((ref1 = prev[1]) === '||' || ref1 === '&&') && !prev.spaced) {
           prev[0] = 'COMPOUND_ASSIGN';
           prev[1] += '=';
           prev = this.tokens[this.tokens.length - 2];
           skipToken = true;
         }
         if (prev && prev[0] !== 'PROPERTY') {
-          origin = (ref4 = prev.origin) != null ? ref4 : prev;
+          origin = (ref2 = prev.origin) != null ? ref2 : prev;
           message = isUnassignable(prev[1], origin[1]);
           if (message) {
             this.error(message, origin[2]);
@@ -596,12 +595,12 @@
       } else if (value === '?' && (prev != null ? prev.spaced : void 0)) {
         tag = 'BIN?';
       } else if (prev && !prev.spaced) {
-        if (value === '(' && (ref5 = prev[0], indexOf.call(CALLABLE, ref5) >= 0)) {
+        if (value === '(' && (ref3 = prev[0], indexOf.call(CALLABLE, ref3) >= 0)) {
           if (prev[0] === '?') {
             prev[0] = 'FUNC_EXIST';
           }
           tag = 'CALL_START';
-        } else if (value === '[' && (ref6 = prev[0], indexOf.call(INDEXABLE, ref6) >= 0)) {
+        } else if (value === '[' && (ref4 = prev[0], indexOf.call(INDEXABLE, ref4) >= 0)) {
           tag = 'INDEX_START';
           switch (prev[0]) {
             case '?':
@@ -634,7 +633,7 @@
         return this;
       }
       stack = [];
-      tokens = this.tokens;
+      ({tokens} = this);
       i = tokens.length;
       tokens[--i][0] = 'PARAM_END';
       while (tok = tokens[--i]) {
@@ -662,7 +661,7 @@
     }
 
     matchWithInterpolations(regex, delimiter) {
-      var close, column, firstToken, index, lastToken, line, nested, offsetInChunk, open, ref2, ref3, ref4, str, strPart, tokens;
+      var close, column, firstToken, index, lastToken, line, nested, offsetInChunk, open, ref, str, strPart, tokens;
       tokens = [];
       offsetInChunk = delimiter.length;
       if (this.chunk.slice(0, offsetInChunk) !== delimiter) {
@@ -670,10 +669,10 @@
       }
       str = this.chunk.slice(offsetInChunk);
       while (true) {
-        strPart = regex.exec(str)[0];
+        [strPart] = regex.exec(str);
         this.validateEscapes(strPart, {
           isRegex: delimiter.charAt(0) === '/',
-          offsetInChunk: offsetInChunk
+          offsetInChunk
         });
         tokens.push(this.makeToken('NEOSTRING', strPart, offsetInChunk));
         str = str.slice(strPart.length);
@@ -681,18 +680,21 @@
         if (str.slice(0, 2) !== '#{') {
           break;
         }
-        ref2 = this.getLineAndColumnFromChunk(offsetInChunk + 1), line = ref2[0], column = ref2[1];
-        ref3 = new Lexer().tokenize(str.slice(1), {
+        [line, column] = this.getLineAndColumnFromChunk(offsetInChunk + 1);
+        ({
+          tokens: nested,
+          index
+        } = new Lexer().tokenize(str.slice(1), {
           line: line,
           column: column,
           untilBalanced: true
-        }), nested = ref3.tokens, index = ref3.index;
+        }));
         index += 1;
         open = nested[0], close = nested[nested.length - 1];
         open[0] = open[1] = '(';
         close[0] = close[1] = ')';
         close.origin = ['', 'end of interpolation', close[2]];
-        if (((ref4 = nested[1]) != null ? ref4[0] : void 0) === 'TERMINATOR') {
+        if (((ref = nested[1]) != null ? ref[0] : void 0) === 'TERMINATOR') {
           nested.splice(1, 1);
         }
         tokens.push(['TOKENS', nested]);
@@ -716,7 +718,7 @@
         lastToken[2].last_column -= 1;
       }
       return {
-        tokens: tokens,
+        tokens,
         index: offsetInChunk + delimiter.length
       };
     }
@@ -729,7 +731,7 @@
       firstIndex = this.tokens.length;
       for (i = j = 0, len = tokens.length; j < len; i = ++j) {
         token = tokens[i];
-        tag = token[0], value = token[1];
+        [tag, value] = token;
         switch (tag) {
           case 'TOKENS':
             if (value.length === 2) {
@@ -787,13 +789,13 @@
     }
 
     pair(tag) {
-      var lastIndent, prev, ref2, ref3, wanted;
-      ref2 = this.ends, prev = ref2[ref2.length - 1];
+      var lastIndent, prev, ref, ref1, wanted;
+      ref = this.ends, prev = ref[ref.length - 1];
       if (tag !== (wanted = prev != null ? prev.tag : void 0)) {
         if ('OUTDENT' !== wanted) {
           this.error(`unmatched ${tag}`);
         }
-        ref3 = this.indents, lastIndent = ref3[ref3.length - 1];
+        ref1 = this.indents, lastIndent = ref1[ref1.length - 1];
         this.outdentToken(lastIndent, true);
         return this.pair(tag);
       }
@@ -801,7 +803,7 @@
     }
 
     getLineAndColumnFromChunk(offset) {
-      var column, lastLine, lineCount, ref2, string;
+      var column, lastLine, lineCount, ref, string;
       if (offset === 0) {
         return [this.chunkLine, this.chunkColumn];
       }
@@ -813,7 +815,7 @@
       lineCount = count(string, '\n');
       column = this.chunkColumn;
       if (lineCount > 0) {
-        ref2 = string.split('\n'), lastLine = ref2[ref2.length - 1];
+        ref = string.split('\n'), lastLine = ref[ref.length - 1];
         column = lastLine.length;
       } else {
         column += string.length;
@@ -822,11 +824,11 @@
     }
 
     makeToken(tag, value, offsetInChunk = 0, length = value.length) {
-      var lastCharacter, locationData, ref2, ref3, token;
+      var lastCharacter, locationData, token;
       locationData = {};
-      ref2 = this.getLineAndColumnFromChunk(offsetInChunk), locationData.first_line = ref2[0], locationData.first_column = ref2[1];
+      [locationData.first_line, locationData.first_column] = this.getLineAndColumnFromChunk(offsetInChunk);
       lastCharacter = length > 0 ? length - 1 : 0;
-      ref3 = this.getLineAndColumnFromChunk(offsetInChunk + lastCharacter), locationData.last_line = ref3[0], locationData.last_column = ref3[1];
+      [locationData.last_line, locationData.last_column] = this.getLineAndColumnFromChunk(offsetInChunk + lastCharacter);
       token = [tag, value, locationData];
       return token;
     }
@@ -842,20 +844,20 @@
     }
 
     tag() {
-      var ref2, token;
-      ref2 = this.tokens, token = ref2[ref2.length - 1];
+      var ref, token;
+      ref = this.tokens, token = ref[ref.length - 1];
       return token != null ? token[0] : void 0;
     }
 
     value() {
-      var ref2, token;
-      ref2 = this.tokens, token = ref2[ref2.length - 1];
+      var ref, token;
+      ref = this.tokens, token = ref[ref.length - 1];
       return token != null ? token[1] : void 0;
     }
 
     unfinished() {
-      var ref2;
-      return LINE_CONTINUER.test(this.chunk) || ((ref2 = this.tag()) === '\\' || ref2 === '.' || ref2 === '?.' || ref2 === '?::' || ref2 === 'UNARY' || ref2 === 'MATH' || ref2 === 'UNARY_MATH' || ref2 === '+' || ref2 === '-' || ref2 === '**' || ref2 === 'SHIFT' || ref2 === 'RELATION' || ref2 === 'COMPARE' || ref2 === '&' || ref2 === '^' || ref2 === '|' || ref2 === '&&' || ref2 === '||' || ref2 === 'BIN?' || ref2 === 'THROW' || ref2 === 'EXTENDS');
+      var ref;
+      return LINE_CONTINUER.test(this.chunk) || ((ref = this.tag()) === '\\' || ref === '.' || ref === '?.' || ref === '?::' || ref === 'UNARY' || ref === 'MATH' || ref === 'UNARY_MATH' || ref === '+' || ref === '-' || ref === '**' || ref === 'SHIFT' || ref === 'RELATION' || ref === 'COMPARE' || ref === '&' || ref === '^' || ref === '|' || ref === '&&' || ref === '||' || ref === 'BIN?' || ref === 'THROW' || ref === 'EXTENDS');
     }
 
     formatString(str) {
@@ -867,7 +869,7 @@
     }
 
     validateEscapes(str, options = {}) {
-      var before, hex, invalidEscape, match, message, octal, ref2, unicode;
+      var before, hex, invalidEscape, match, message, octal, ref, unicode;
       match = INVALID_ESCAPE.exec(str);
       if (!match) {
         return;
@@ -879,7 +881,7 @@
       message = octal ? "octal escape sequences are not allowed" : "invalid escape sequence";
       invalidEscape = `\\${octal || hex || unicode}`;
       return this.error(`${message} ${invalidEscape}`, {
-        offset: ((ref2 = options.offsetInChunk) != null ? ref2 : 0) + match.index + before.length,
+        offset: ((ref = options.offsetInChunk) != null ? ref : 0) + match.index + before.length,
         length: invalidEscape.length
       });
     }
@@ -922,11 +924,11 @@
     }
 
     error(message, options = {}) {
-      var first_column, first_line, location, ref2, ref3, ref4;
-      location = 'first_line' in options ? options : ((ref3 = this.getLineAndColumnFromChunk((ref2 = options.offset) != null ? ref2 : 0), first_line = ref3[0], first_column = ref3[1], ref3), {
-        first_line: first_line,
-        first_column: first_column,
-        last_column: first_column + ((ref4 = options.length) != null ? ref4 : 1) - 1
+      var first_column, first_line, location, ref, ref1;
+      location = 'first_line' in options ? options : ([first_line, first_column] = this.getLineAndColumnFromChunk((ref = options.offset) != null ? ref : 0), {
+        first_line,
+        first_column,
+        last_column: first_column + ((ref1 = options.length) != null ? ref1 : 1) - 1
       });
       return throwSyntaxError(message, location);
     }
@@ -949,7 +951,7 @@
   exports.isUnassignable = isUnassignable;
 
   isForFrom = function(prev) {
-    var ref2;
+    var ref;
     if (prev[0] === 'IDENTIFIER') {
       if (prev[1] === 'from') {
         prev[1][0] = 'IDENTIFIER';
@@ -958,7 +960,7 @@
       return true;
     } else if (prev[0] === 'FOR') {
       return false;
-    } else if ((ref2 = prev[1]) === '{' || ref2 === '[' || ref2 === ',' || ref2 === ':') {
+    } else if ((ref = prev[1]) === '{' || ref === '[' || ref === ',' || ref === ':') {
       return false;
     } else {
       return true;
diff --git a/lib/coffeescript/nodes.js b/lib/coffeescript/nodes.js
index 9162cb7958..c076004cb2 100644
--- a/lib/coffeescript/nodes.js
+++ b/lib/coffeescript/nodes.js
@@ -1,16 +1,16 @@
 // Generated by CoffeeScript 2.0.0-alpha1
 (function() {
-  var Access, Arr, Assign, AwaitReturn, Base, Block, BooleanLiteral, Call, Class, Code, CodeFragment, Comment, ExecutableClassBody, Existence, Expansion, ExportAllDeclaration, ExportDeclaration, ExportDefaultDeclaration, ExportNamedDeclaration, ExportSpecifier, ExportSpecifierList, Extends, For, HoistTarget, IdentifierLiteral, If, ImportClause, ImportDeclaration, ImportDefaultSpecifier, ImportNamespaceSpecifier, ImportSpecifier, ImportSpecifierList, In, Index, InfinityLiteral, JS_FORBIDDEN, LEVEL_ACCESS, LEVEL_COND, LEVEL_LIST, LEVEL_OP, LEVEL_PAREN, LEVEL_TOP, Literal, ModuleDeclaration, ModuleSpecifier, ModuleSpecifierList, NEGATE, NO, NaNLiteral, NullLiteral, NumberLiteral, Obj, Op, Param, Parens, PassthroughLiteral, PropertyName, Range, RegexLiteral, RegexWithInterpolations, Return, SIMPLENUM, Scope, Slice, Splat, StatementLiteral, StringLiteral, StringWithInterpolations, Super, SuperCall, Switch, TAB, THIS, TaggedTemplateCall, ThisLiteral, Throw, Try, UTILITIES, UndefinedLiteral, Value, While, YES, YieldReturn, addLocationDataFn, compact, del, ends, extend, flatten, fragmentsToText, isLiteralArguments, isLiteralThis, isUnassignable, locationDataToString, merge, multident, ref1, ref2, shouldCacheOrIsAssignable, some, starts, throwSyntaxError, unfoldSoak, utility,
+  var Access, Arr, Assign, AwaitReturn, Base, Block, BooleanLiteral, Call, Class, Code, CodeFragment, Comment, ExecutableClassBody, Existence, Expansion, ExportAllDeclaration, ExportDeclaration, ExportDefaultDeclaration, ExportNamedDeclaration, ExportSpecifier, ExportSpecifierList, Extends, For, HoistTarget, IdentifierLiteral, If, ImportClause, ImportDeclaration, ImportDefaultSpecifier, ImportNamespaceSpecifier, ImportSpecifier, ImportSpecifierList, In, Index, InfinityLiteral, JS_FORBIDDEN, LEVEL_ACCESS, LEVEL_COND, LEVEL_LIST, LEVEL_OP, LEVEL_PAREN, LEVEL_TOP, Literal, ModuleDeclaration, ModuleSpecifier, ModuleSpecifierList, NEGATE, NO, NaNLiteral, NullLiteral, NumberLiteral, Obj, Op, Param, Parens, PassthroughLiteral, PropertyName, Range, RegexLiteral, RegexWithInterpolations, Return, SIMPLENUM, Scope, Slice, Splat, StatementLiteral, StringLiteral, StringWithInterpolations, Super, SuperCall, Switch, TAB, THIS, TaggedTemplateCall, ThisLiteral, Throw, Try, UTILITIES, UndefinedLiteral, Value, While, YES, YieldReturn, addLocationDataFn, compact, del, ends, extend, flatten, fragmentsToText, isLiteralArguments, isLiteralThis, isUnassignable, locationDataToString, merge, multident, shouldCacheOrIsAssignable, some, starts, throwSyntaxError, unfoldSoak, utility,
     indexOf = [].indexOf || function(item) { for (var i = 0, l = this.length; i < l; i++) { if (i in this && this[i] === item) return i; } return -1; },
     slice = [].slice;
 
   Error.stackTraceLimit = 2e308;
 
-  Scope = require('./scope').Scope;
+  ({Scope} = require('./scope'));
 
-  ref1 = require('./lexer'), isUnassignable = ref1.isUnassignable, JS_FORBIDDEN = ref1.JS_FORBIDDEN;
+  ({isUnassignable, JS_FORBIDDEN} = require('./lexer'));
 
-  ref2 = require('./helpers'), compact = ref2.compact, flatten = ref2.flatten, extend = ref2.extend, merge = ref2.merge, del = ref2.del, starts = ref2.starts, ends = ref2.ends, some = ref2.some, addLocationDataFn = ref2.addLocationDataFn, locationDataToString = ref2.locationDataToString, throwSyntaxError = ref2.throwSyntaxError;
+  ({compact, flatten, extend, merge, del, starts, ends, some, addLocationDataFn, locationDataToString, throwSyntaxError} = require('./helpers'));
 
   exports.extend = extend;
 
@@ -35,10 +35,10 @@
 
   exports.CodeFragment = CodeFragment = class CodeFragment {
     constructor(parent, code) {
-      var ref3;
+      var ref1;
       this.code = `${code}`;
       this.locationData = parent != null ? parent.locationData : void 0;
-      this.type = (parent != null ? (ref3 = parent.constructor) != null ? ref3.name : void 0 : void 0) || 'unknown';
+      this.type = (parent != null ? (ref1 = parent.constructor) != null ? ref1.name : void 0 : void 0) || 'unknown';
     }
 
     toString() {
@@ -82,7 +82,7 @@
       }
 
       compileClosure(o) {
-        var args, argumentsNode, func, jumpNode, meth, parts, ref3, ref4;
+        var args, argumentsNode, func, jumpNode, meth, parts, ref1, ref2;
         if (jumpNode = this.jumps()) {
           jumpNode.error('cannot use a pure statement in an expression');
         }
@@ -105,11 +105,11 @@
         }
         parts = (new Call(func, args)).compileNode(o);
         switch (false) {
-          case !(func.isGenerator || ((ref3 = func.base) != null ? ref3.isGenerator : void 0)):
+          case !(func.isGenerator || ((ref1 = func.base) != null ? ref1.isGenerator : void 0)):
             parts.unshift(this.makeCode("(yield* "));
             parts.push(this.makeCode(")"));
             break;
-          case !(func.isAsync || ((ref4 = func.base) != null ? ref4.isAsync : void 0)):
+          case !(func.isAsync || ((ref2 = func.base) != null ? ref2.isAsync : void 0)):
             parts.unshift(this.makeCode("(await "));
             parts.push(this.makeCode(")"));
         }
@@ -198,17 +198,17 @@
       }
 
       eachChild(func) {
-        var attr, child, j, k, len1, len2, ref3, ref4;
+        var attr, child, j, k, len1, len2, ref1, ref2;
         if (!this.children) {
           return this;
         }
-        ref3 = this.children;
-        for (j = 0, len1 = ref3.length; j < len1; j++) {
-          attr = ref3[j];
+        ref1 = this.children;
+        for (j = 0, len1 = ref1.length; j < len1; j++) {
+          attr = ref1[j];
           if (this[attr]) {
-            ref4 = flatten([this[attr]]);
-            for (k = 0, len2 = ref4.length; k < len2; k++) {
-              child = ref4[k];
+            ref2 = flatten([this[attr]]);
+            for (k = 0, len2 = ref2.length; k < len2; k++) {
+              child = ref2[k];
               if (func(child) === false) {
                 return this;
               }
@@ -229,19 +229,19 @@
       }
 
       replaceInContext(match, replacement) {
-        var attr, child, children, i, j, k, len1, len2, ref3, ref4;
+        var attr, child, children, i, j, k, len1, len2, ref1, ref2;
         if (!this.children) {
           return false;
         }
-        ref3 = this.children;
-        for (j = 0, len1 = ref3.length; j < len1; j++) {
-          attr = ref3[j];
+        ref1 = this.children;
+        for (j = 0, len1 = ref1.length; j < len1; j++) {
+          attr = ref1[j];
           if (children = this[attr]) {
             if (Array.isArray(children)) {
               for (i = k = 0, len2 = children.length; k < len2; i = ++k) {
                 child = children[i];
                 if (match(child)) {
-                  [].splice.apply(children, [i, i - i + 1].concat(ref4 = replacement(child, this))), ref4;
+                  [].splice.apply(children, [i, i - i + 1].concat(ref2 = replacement(child, this))), ref2;
                   return true;
                 } else {
                   if (child.replaceInContext(match, replacement)) {
@@ -337,11 +337,11 @@
 
   exports.HoistTarget = HoistTarget = class HoistTarget extends Base {
     static expand(fragments) {
-      var fragment, i, j, ref3;
+      var fragment, i, j, ref1;
       for (i = j = fragments.length - 1; j >= 0; i = j += -1) {
         fragment = fragments[i];
         if (fragment.fragments) {
-          [].splice.apply(fragments, [i, i - i + 1].concat(ref3 = this.expand(fragment.fragments))), ref3;
+          [].splice.apply(fragments, [i, i - i + 1].concat(ref1 = this.expand(fragment.fragments))), ref1;
         }
       }
       return fragments;
@@ -414,10 +414,10 @@
       }
 
       isStatement(o) {
-        var exp, j, len1, ref3;
-        ref3 = this.expressions;
-        for (j = 0, len1 = ref3.length; j < len1; j++) {
-          exp = ref3[j];
+        var exp, j, len1, ref1;
+        ref1 = this.expressions;
+        for (j = 0, len1 = ref1.length; j < len1; j++) {
+          exp = ref1[j];
           if (exp.isStatement(o)) {
             return true;
           }
@@ -426,10 +426,10 @@
       }
 
       jumps(o) {
-        var exp, j, jumpNode, len1, ref3;
-        ref3 = this.expressions;
-        for (j = 0, len1 = ref3.length; j < len1; j++) {
-          exp = ref3[j];
+        var exp, j, jumpNode, len1, ref1;
+        ref1 = this.expressions;
+        for (j = 0, len1 = ref1.length; j < len1; j++) {
+          exp = ref1[j];
           if (jumpNode = exp.jumps(o)) {
             return jumpNode;
           }
@@ -461,13 +461,13 @@
       }
 
       compileNode(o) {
-        var answer, compiledNodes, fragments, index, j, len1, node, ref3, top;
+        var answer, compiledNodes, fragments, index, j, len1, node, ref1, top;
         this.tab = o.indent;
         top = o.level === LEVEL_TOP;
         compiledNodes = [];
-        ref3 = this.expressions;
-        for (index = j = 0, len1 = ref3.length; j < len1; index = ++j) {
-          node = ref3[index];
+        ref1 = this.expressions;
+        for (index = j = 0, len1 = ref1.length; j < len1; index = ++j) {
+          node = ref1[index];
           node = node.unwrapAll();
           node = node.unfoldSoak(o) || node;
           if (node instanceof Block) {
@@ -506,24 +506,24 @@
       }
 
       compileRoot(o) {
-        var exp, fragments, i, j, len1, name, prelude, preludeExps, ref3, ref4, rest;
+        var exp, fragments, i, j, len1, name, prelude, preludeExps, ref1, ref2, rest;
         o.indent = o.bare ? '' : TAB;
         o.level = LEVEL_TOP;
         this.spaced = true;
-        o.scope = new Scope(null, this, null, (ref3 = o.referencedVars) != null ? ref3 : []);
-        ref4 = o.locals || [];
-        for (j = 0, len1 = ref4.length; j < len1; j++) {
-          name = ref4[j];
+        o.scope = new Scope(null, this, null, (ref1 = o.referencedVars) != null ? ref1 : []);
+        ref2 = o.locals || [];
+        for (j = 0, len1 = ref2.length; j < len1; j++) {
+          name = ref2[j];
           o.scope.parameter(name);
         }
         prelude = [];
         if (!o.bare) {
           preludeExps = (function() {
-            var k, len2, ref5, results;
-            ref5 = this.expressions;
+            var k, len2, ref3, results;
+            ref3 = this.expressions;
             results = [];
-            for (i = k = 0, len2 = ref5.length; k < len2; i = ++k) {
-              exp = ref5[i];
+            for (i = k = 0, len2 = ref3.length; k < len2; i = ++k) {
+              exp = ref3[i];
               if (!(exp.unwrap() instanceof Comment)) {
                 break;
               }
@@ -550,12 +550,12 @@
       }
 
       compileWithDeclarations(o) {
-        var assigns, declars, exp, fragments, i, j, len1, post, ref3, ref4, ref5, rest, scope, spaced;
+        var assigns, declars, exp, fragments, i, j, len1, post, ref1, rest, scope, spaced;
         fragments = [];
         post = [];
-        ref3 = this.expressions;
-        for (i = j = 0, len1 = ref3.length; j < len1; i = ++j) {
-          exp = ref3[i];
+        ref1 = this.expressions;
+        for (i = j = 0, len1 = ref1.length; j < len1; i = ++j) {
+          exp = ref1[i];
           exp = exp.unwrap();
           if (!(exp instanceof Comment || exp instanceof Literal)) {
             break;
@@ -566,12 +566,12 @@
         });
         if (i) {
           rest = this.expressions.splice(i, 9e9);
-          ref4 = [this.spaced, false], spaced = ref4[0], this.spaced = ref4[1];
-          ref5 = [this.compileNode(o), spaced], fragments = ref5[0], this.spaced = ref5[1];
+          [spaced, this.spaced] = [this.spaced, false];
+          [fragments, this.spaced] = [this.compileNode(o), spaced];
           this.expressions = rest;
         }
         post = this.compileNode(o);
-        scope = o.scope;
+        ({scope} = o);
         if (scope.expressions === this) {
           declars = o.scope.hasDeclarations();
           assigns = scope.hasAssignments;
@@ -672,7 +672,12 @@
   exports.PassthroughLiteral = PassthroughLiteral = class PassthroughLiteral extends Literal {};
 
   exports.IdentifierLiteral = IdentifierLiteral = (function() {
-    class IdentifierLiteral extends Literal {};
+    class IdentifierLiteral extends Literal {
+      eachName(iterator) {
+        return iterator(this);
+      }
+
+    };
 
     IdentifierLiteral.prototype.isAssignable = YES;
 
@@ -720,8 +725,8 @@
     }
 
     compileNode(o) {
-      var code, ref3;
-      code = ((ref3 = o.scope.method) != null ? ref3.bound : void 0) ? o.scope.method.context : this.value;
+      var code, ref1;
+      code = ((ref1 = o.scope.method) != null ? ref1.bound : void 0) ? o.scope.method.context : this.value;
       return [this.makeCode(code)];
     }
 
@@ -755,8 +760,8 @@
       }
 
       compileToFragments(o, level) {
-        var expr, ref3;
-        expr = (ref3 = this.expression) != null ? ref3.makeReturn() : void 0;
+        var expr, ref1;
+        expr = (ref1 = this.expression) != null ? ref1.makeReturn() : void 0;
         if (expr && !(expr instanceof Return)) {
           return expr.compileToFragments(o, level);
         } else {
@@ -878,10 +883,10 @@
       }
 
       isAtomic() {
-        var j, len1, node, ref3;
-        ref3 = this.properties.concat(this.base);
-        for (j = 0, len1 = ref3.length; j < len1; j++) {
-          node = ref3[j];
+        var j, len1, node, ref1;
+        ref1 = this.properties.concat(this.base);
+        for (j = 0, len1 = ref1.length; j < len1; j++) {
+          node = ref1[j];
           if (node.soak || node instanceof Call) {
             return false;
           }
@@ -913,14 +918,14 @@
       }
 
       isSplice() {
-        var lastProp, ref3;
-        ref3 = this.properties, lastProp = ref3[ref3.length - 1];
+        var lastProp, ref1;
+        ref1 = this.properties, lastProp = ref1[ref1.length - 1];
         return lastProp instanceof Slice;
       }
 
       looksStatic(className) {
-        var ref3;
-        return (this["this"] || this.base instanceof ThisLiteral || this.base.value === className) && this.properties.length === 1 && ((ref3 = this.properties[0].name) != null ? ref3.value : void 0) !== 'prototype';
+        var ref1;
+        return (this["this"] || this.base instanceof ThisLiteral || this.base.value === className) && this.properties.length === 1 && ((ref1 = this.properties[0].name) != null ? ref1.value : void 0) !== 'prototype';
       }
 
       unwrap() {
@@ -932,8 +937,8 @@
       }
 
       cacheReference(o) {
-        var base, bref, name, nref, ref3;
-        ref3 = this.properties, name = ref3[ref3.length - 1];
+        var base, bref, name, nref, ref1;
+        ref1 = this.properties, name = ref1[ref1.length - 1];
         if (this.properties.length < 2 && !this.base.shouldCache() && !(name != null ? name.shouldCache() : void 0)) {
           return [this, this];
         }
@@ -970,14 +975,14 @@
 
       unfoldSoak(o) {
         return this.unfoldedSoak != null ? this.unfoldedSoak : this.unfoldedSoak = (() => {
-          var fst, i, ifn, j, len1, prop, ref, ref3, snd;
+          var fst, i, ifn, j, len1, prop, ref, ref1, snd;
           if (ifn = this.base.unfoldSoak(o)) {
             ifn.body.properties.push(...this.properties);
             return ifn;
           }
-          ref3 = this.properties;
-          for (i = j = 0, len1 = ref3.length; j < len1; i = ++j) {
-            prop = ref3[i];
+          ref1 = this.properties;
+          for (i = j = 0, len1 = ref1.length; j < len1; i = ++j) {
+            prop = ref1[i];
             if (!prop.soak) {
               continue;
             }
@@ -997,6 +1002,16 @@
         })();
       }
 
+      eachName(iterator) {
+        if (this.hasProperties()) {
+          return iterator(this);
+        } else if (this.base.isAssignable()) {
+          return this.base.eachName(iterator);
+        } else {
+          return this.error('tried to assign to unassignable value');
+        }
+      }
+
     };
 
     Value.prototype.children = ['base', 'properties'];
@@ -1046,11 +1061,11 @@
       }
 
       updateLocationDataIfMissing(locationData) {
-        var base, ref3;
+        var base, ref1;
         if (this.locationData && this.needsUpdatedStartLocation) {
           this.locationData.first_line = locationData.first_line;
           this.locationData.first_column = locationData.first_column;
-          base = ((ref3 = this.variable) != null ? ref3.base : void 0) || this.variable;
+          base = ((ref1 = this.variable) != null ? ref1.base : void 0) || this.variable;
           if (base.needsUpdatedStartLocation) {
             this.variable.locationData.first_line = locationData.first_line;
             this.variable.locationData.first_column = locationData.first_column;
@@ -1062,8 +1077,8 @@
       }
 
       newInstance() {
-        var base, ref3;
-        base = ((ref3 = this.variable) != null ? ref3.base : void 0) || this.variable;
+        var base, ref1;
+        base = ((ref1 = this.variable) != null ? ref1.base : void 0) || this.variable;
         if (base instanceof Call && !base.isNew) {
           base.newInstance();
         } else {
@@ -1074,7 +1089,7 @@
       }
 
       unfoldSoak(o) {
-        var call, ifn, j, left, len1, list, ref3, ref4, rite;
+        var call, ifn, j, left, len1, list, ref1, rite;
         if (this.soak) {
           if (this.variable instanceof Super) {
             left = new Literal(this.variable.compile(o));
@@ -1086,7 +1101,7 @@
             if (ifn = unfoldSoak(o, this, 'variable')) {
               return ifn;
             }
-            ref3 = new Value(this.variable).cacheReference(o), left = ref3[0], rite = ref3[1];
+            [left, rite] = new Value(this.variable).cacheReference(o);
           }
           rite = new Call(rite, this.args);
           rite.isNew = this.isNew;
@@ -1111,9 +1126,9 @@
             break;
           }
         }
-        ref4 = list.reverse();
-        for (j = 0, len1 = ref4.length; j < len1; j++) {
-          call = ref4[j];
+        ref1 = list.reverse();
+        for (j = 0, len1 = ref1.length; j < len1; j++) {
+          call = ref1[j];
           if (ifn) {
             if (call.variable instanceof Call) {
               call.variable = ifn;
@@ -1127,14 +1142,14 @@
       }
 
       compileNode(o) {
-        var arg, argIndex, compiledArgs, fragments, j, len1, ref3, ref4;
-        if ((ref3 = this.variable) != null) {
-          ref3.front = this.front;
+        var arg, argIndex, compiledArgs, fragments, j, len1, ref1, ref2;
+        if ((ref1 = this.variable) != null) {
+          ref1.front = this.front;
         }
         compiledArgs = [];
-        ref4 = this.args;
-        for (argIndex = j = 0, len1 = ref4.length; j < len1; argIndex = ++j) {
-          arg = ref4[argIndex];
+        ref2 = this.args;
+        for (argIndex = j = 0, len1 = ref2.length; j < len1; argIndex = ++j) {
+          arg = ref2[argIndex];
           if (argIndex) {
             compiledArgs.push(this.makeCode(", "));
           }
@@ -1163,19 +1178,19 @@
   exports.SuperCall = SuperCall = (function() {
     class SuperCall extends Call {
       isStatement(o) {
-        var ref3;
-        return ((ref3 = this.expressions) != null ? ref3.length : void 0) && o.level === LEVEL_TOP;
+        var ref1;
+        return ((ref1 = this.expressions) != null ? ref1.length : void 0) && o.level === LEVEL_TOP;
       }
 
       compileNode(o) {
-        var ref, ref3, ref4, replacement, superCall;
-        if (!((ref3 = this.expressions) != null ? ref3.length : void 0)) {
+        var ref, ref1, replacement, superCall;
+        if (!((ref1 = this.expressions) != null ? ref1.length : void 0)) {
           return super.compileNode(o);
         }
         superCall = new Literal(fragmentsToText(super.compileNode(o)));
         replacement = new Block(this.expressions.slice());
         if (o.level > LEVEL_TOP) {
-          ref4 = superCall.cache(o, null, YES), superCall = ref4[0], ref = ref4[1];
+          [superCall, ref] = superCall.cache(o, null, YES);
           replacement.push(ref);
         }
         replacement.unshift(superCall);
@@ -1205,7 +1220,7 @@
         }
         this.inCtor = !!method.ctor;
         if (!(this.inCtor || (this.accessor != null))) {
-          name = method.name, variable = method.variable;
+          ({name, variable} = method);
           if (name.shouldCache() || (name instanceof Index && name.index.isAssignable())) {
             nref = new IdentifierLiteral(o.scope.parent.freeVariable('name'));
             name.index = new Assign(nref, name.index);
@@ -1273,11 +1288,11 @@
       }
 
       compileToFragments(o) {
-        var name, node, ref3;
+        var name, node, ref1;
         name = this.name.compileToFragments(o);
         node = this.name.unwrap();
         if (node instanceof PropertyName) {
-          if (ref3 = node.value, indexOf.call(JS_FORBIDDEN, ref3) >= 0) {
+          if (ref1 = node.value, indexOf.call(JS_FORBIDDEN, ref1) >= 0) {
             return [this.makeCode('["'), ...name, this.makeCode('"]')];
           } else {
             return [this.makeCode('.'), ...name];
@@ -1331,15 +1346,15 @@
       }
 
       compileVariables(o) {
-        var ref3, ref4, ref5, shouldCache, step;
+        var shouldCache, step;
         o = merge(o, {
           top: true
         });
         shouldCache = del(o, 'shouldCache');
-        ref3 = this.cacheToCodeFragments(this.from.cache(o, LEVEL_LIST, shouldCache)), this.fromC = ref3[0], this.fromVar = ref3[1];
-        ref4 = this.cacheToCodeFragments(this.to.cache(o, LEVEL_LIST, shouldCache)), this.toC = ref4[0], this.toVar = ref4[1];
+        [this.fromC, this.fromVar] = this.cacheToCodeFragments(this.from.cache(o, LEVEL_LIST, shouldCache));
+        [this.toC, this.toVar] = this.cacheToCodeFragments(this.to.cache(o, LEVEL_LIST, shouldCache));
         if (step = del(o, 'step')) {
-          ref5 = this.cacheToCodeFragments(step.cache(o, LEVEL_LIST, shouldCache)), this.step = ref5[0], this.stepVar = ref5[1];
+          [this.step, this.stepVar] = this.cacheToCodeFragments(step.cache(o, LEVEL_LIST, shouldCache));
         }
         this.fromNum = this.from.isNumber() ? Number(this.fromVar) : null;
         this.toNum = this.to.isNumber() ? Number(this.toVar) : null;
@@ -1347,7 +1362,7 @@
       }
 
       compileNode(o) {
-        var cond, condPart, from, gt, idx, idxName, known, lt, namedIndex, ref3, ref4, stepPart, to, varPart;
+        var cond, condPart, from, gt, idx, idxName, known, lt, namedIndex, stepPart, to, varPart;
         if (!this.fromVar) {
           this.compileVariables(o);
         }
@@ -1365,8 +1380,8 @@
         if (this.step !== this.stepVar) {
           varPart += `, ${this.step}`;
         }
-        ref3 = [`${idx} <${this.equals}`, `${idx} >${this.equals}`], lt = ref3[0], gt = ref3[1];
-        condPart = this.stepNum != null ? this.stepNum > 0 ? `${lt} ${this.toVar}` : `${gt} ${this.toVar}` : known ? ((ref4 = [this.fromNum, this.toNum], from = ref4[0], to = ref4[1], ref4), from <= to ? `${lt} ${to}` : `${gt} ${to}`) : (cond = this.stepVar ? `${this.stepVar} > 0` : `${this.fromVar} <= ${this.toVar}`, `${cond} ? ${lt} ${this.toVar} : ${gt} ${this.toVar}`);
+        [lt, gt] = [`${idx} <${this.equals}`, `${idx} >${this.equals}`];
+        condPart = this.stepNum != null ? this.stepNum > 0 ? `${lt} ${this.toVar}` : `${gt} ${this.toVar}` : known ? ([from, to] = [this.fromNum, this.toNum], from <= to ? `${lt} ${to}` : `${gt} ${to}`) : (cond = this.stepVar ? `${this.stepVar} > 0` : `${this.fromVar} <= ${this.toVar}`, `${cond} ? ${lt} ${this.toVar} : ${gt} ${this.toVar}`);
         stepPart = this.stepVar ? `${idx} += ${this.stepVar}` : known ? namedIndex ? from <= to ? `++${idx}` : `--${idx}` : from <= to ? `${idx}++` : `${idx}--` : namedIndex ? `${cond} ? ++${idx} : --${idx}` : `${cond} ? ${idx}++ : ${idx}--`;
         if (namedIndex) {
           varPart = `${idxName} = ${varPart}`;
@@ -1378,12 +1393,12 @@
       }
 
       compileArray(o) {
-        var args, body, cond, hasArgs, i, idt, j, known, post, pre, range, ref3, ref4, result, results, vars;
+        var args, body, cond, hasArgs, i, idt, j, known, post, pre, range, ref1, ref2, result, results, vars;
         known = (this.fromNum != null) && (this.toNum != null);
         if (known && Math.abs(this.fromNum - this.toNum) <= 20) {
           range = (function() {
             results = [];
-            for (var j = ref3 = this.fromNum, ref4 = this.toNum; ref3 <= ref4 ? j <= ref4 : j >= ref4; ref3 <= ref4 ? j++ : j--){ results.push(j); }
+            for (var j = ref1 = this.fromNum, ref2 = this.toNum; ref1 <= ref2 ? j <= ref2 : j >= ref2; ref1 <= ref2 ? j++ : j--){ results.push(j); }
             return results;
           }).apply(this);
           if (this.exclusive) {
@@ -1431,8 +1446,8 @@
       }
 
       compileNode(o) {
-        var compiled, compiledText, from, fromCompiled, ref3, to, toStr;
-        ref3 = this.range, to = ref3.to, from = ref3.from;
+        var compiled, compiledText, from, fromCompiled, to, toStr;
+        ({to, from} = this.range);
         fromCompiled = from && from.compileToFragments(o, LEVEL_PAREN) || [this.makeCode('0')];
         if (to) {
           compiled = to.compileToFragments(o, LEVEL_PAREN);
@@ -1460,8 +1475,23 @@
         this.objects = this.properties = props || [];
       }
 
+      isAssignable() {
+        var j, len1, prop, ref1;
+        ref1 = this.properties;
+        for (j = 0, len1 = ref1.length; j < len1; j++) {
+          prop = ref1[j];
+          if (prop instanceof Assign) {
+            prop = prop.value;
+          }
+          if (!prop.isAssignable()) {
+            return false;
+          }
+        }
+        return true;
+      }
+
       compileNode(o) {
-        var answer, i, idt, indent, j, join, k, key, lastNoncom, len1, len2, node, prop, props, ref3, value;
+        var answer, i, idt, indent, isCompact, j, join, k, key, l, lastNoncom, len1, len2, len3, node, prop, props, ref1, value;
         props = this.properties;
         if (this.generated) {
           for (j = 0, len1 = props.length; j < len1; j++) {
@@ -1473,12 +1503,20 @@
         }
         idt = o.indent += TAB;
         lastNoncom = this.lastNonComment(this.properties);
+        isCompact = true;
+        ref1 = this.properties;
+        for (k = 0, len2 = ref1.length; k < len2; k++) {
+          prop = ref1[k];
+          if (prop instanceof Assign || prop instanceof Comment) {
+            isCompact = false;
+          }
+        }
         answer = [];
-        answer.push(this.makeCode(`{${(props.length === 0 ? '}' : '\n')}`));
-        for (i = k = 0, len2 = props.length; k < len2; i = ++k) {
+        answer.push(this.makeCode(`{${(isCompact ? '' : '\n')}`));
+        for (i = l = 0, len3 = props.length; l < len3; i = ++l) {
           prop = props[i];
-          join = i === props.length - 1 ? '' : prop === lastNoncom || prop instanceof Comment ? '\n' : ',\n';
-          indent = prop instanceof Comment ? '' : idt;
+          join = i === props.length - 1 ? '' : isCompact ? ', ' : prop === lastNoncom || prop instanceof Comment ? '\n' : ',\n';
+          indent = isCompact || prop instanceof Comment ? '' : idt;
           if (prop instanceof Assign) {
             if (prop.context !== 'object') {
               prop.operatorToken.error(`unexpected ${prop.operatorToken.value}`);
@@ -1492,12 +1530,12 @@
           }
           if (!(prop instanceof Comment) && !(prop instanceof Assign)) {
             if (prop.shouldCache()) {
-              ref3 = prop.base.cache(o), key = ref3[0], value = ref3[1];
+              [key, value] = prop.base.cache(o);
               if (key instanceof IdentifierLiteral) {
                 key = new PropertyName(key.value);
               }
               prop = new Assign(key, value, 'object');
-            } else {
+            } else if (!(typeof prop.bareLiteral === "function" ? prop.bareLiteral(IdentifierLiteral) : void 0)) {
               prop = new Assign(prop, prop, 'object');
             }
           }
@@ -1509,9 +1547,7 @@
             answer.push(this.makeCode(join));
           }
         }
-        if (props.length !== 0) {
-          answer.push(this.makeCode(`\n${this.tab}}`));
-        }
+        answer.push(this.makeCode(`${(isCompact ? '' : `\n${this.tab}`)}}`));
         if (this.front) {
           return this.wrapInBraces(answer);
         } else {
@@ -1520,10 +1556,10 @@
       }
 
       assigns(name) {
-        var j, len1, prop, ref3;
-        ref3 = this.properties;
-        for (j = 0, len1 = ref3.length; j < len1; j++) {
-          prop = ref3[j];
+        var j, len1, prop, ref1;
+        ref1 = this.properties;
+        for (j = 0, len1 = ref1.length; j < len1; j++) {
+          prop = ref1[j];
           if (prop.assigns(name)) {
             return true;
           }
@@ -1531,6 +1567,21 @@
         return false;
       }
 
+      eachName(iterator) {
+        var j, len1, prop, ref1, results;
+        ref1 = this.properties;
+        results = [];
+        for (j = 0, len1 = ref1.length; j < len1; j++) {
+          prop = ref1[j];
+          if (prop instanceof Assign) {
+            prop = prop.value;
+          }
+          prop = prop.unwrapAll();
+          results.push(prop.eachName(iterator));
+        }
+        return results;
+      }
+
     };
 
     Obj.prototype.children = ['properties'];
@@ -1546,6 +1597,24 @@
         this.objects = objs || [];
       }
 
+      isAssignable() {
+        var i, j, len1, obj, ref1;
+        if (!this.objects.length) {
+          return false;
+        }
+        ref1 = this.objects;
+        for (i = j = 0, len1 = ref1.length; j < len1; i = ++j) {
+          obj = ref1[i];
+          if (obj instanceof Splat && i + 1 !== this.objects.length) {
+            return false;
+          }
+          if (!(obj.isAssignable() && (!obj.isAtomic || obj.isAtomic()))) {
+            return false;
+          }
+        }
+        return true;
+      }
+
       compileNode(o) {
         var answer, compiledObjs, fragments, index, j, len1, obj;
         if (!this.objects.length) {
@@ -1554,11 +1623,11 @@
         o.indent += TAB;
         answer = [];
         compiledObjs = (function() {
-          var j, len1, ref3, results;
-          ref3 = this.objects;
+          var j, len1, ref1, results;
+          ref1 = this.objects;
           results = [];
-          for (j = 0, len1 = ref3.length; j < len1; j++) {
-            obj = ref3[j];
+          for (j = 0, len1 = ref1.length; j < len1; j++) {
+            obj = ref1[j];
             results.push(obj.compileToFragments(o, LEVEL_LIST));
           }
           return results;
@@ -1581,10 +1650,10 @@
       }
 
       assigns(name) {
-        var j, len1, obj, ref3;
-        ref3 = this.objects;
-        for (j = 0, len1 = ref3.length; j < len1; j++) {
-          obj = ref3[j];
+        var j, len1, obj, ref1;
+        ref1 = this.objects;
+        for (j = 0, len1 = ref1.length; j < len1; j++) {
+          obj = ref1[j];
           if (obj.assigns(name)) {
             return true;
           }
@@ -1592,6 +1661,18 @@
         return false;
       }
 
+      eachName(iterator) {
+        var j, len1, obj, ref1, results;
+        ref1 = this.objects;
+        results = [];
+        for (j = 0, len1 = ref1.length; j < len1; j++) {
+          obj = ref1[j];
+          obj = obj.unwrapAll();
+          results.push(obj.eachName(iterator));
+        }
+        return results;
+      }
+
     };
 
     Arr.prototype.children = ['objects'];
@@ -1628,9 +1709,7 @@
           }
         }
         if (this.variable) {
-          assign = new Assign(this.variable, new Literal(''), null, {
-            moduleDeclaration: this.moduleDeclaration
-          });
+          assign = new Assign(this.variable, new Literal(''), null, {moduleDeclaration: this.moduleDeclaration});
           return [...assign.compileToFragments(o), ...result];
         } else {
           return result;
@@ -1638,14 +1717,14 @@
       }
 
       compileClassDeclaration(o) {
-        var ref3, result;
+        var ref1, result;
         if (this.externalCtor || this.boundMethods.length) {
           if (this.ctor == null) {
             this.ctor = this.makeDefaultConstructor();
           }
         }
-        if ((ref3 = this.ctor) != null) {
-          ref3.noReturn = true;
+        if ((ref1 = this.ctor) != null) {
+          ref1.noReturn = true;
         }
         if (this.boundMethods.length) {
           this.proxyBoundMethods(o);
@@ -1671,11 +1750,11 @@
       }
 
       determineName() {
-        var message, name, node, ref3, tail;
+        var message, name, node, ref1, tail;
         if (!this.variable) {
           return null;
         }
-        ref3 = this.variable.properties, tail = ref3[ref3.length - 1];
+        ref1 = this.variable.properties, tail = ref1[ref1.length - 1];
         node = tail ? tail instanceof Access && tail.name : this.variable.base;
         if (!(node instanceof IdentifierLiteral || node instanceof PropertyName)) {
           return null;
@@ -1695,18 +1774,18 @@
       }
 
       walkBody() {
-        var assign, end, executableBody, expression, expressions, exprs, i, initializer, initializerExpression, j, k, len1, len2, method, properties, pushSlice, ref3, start;
+        var assign, end, executableBody, expression, expressions, exprs, i, initializer, initializerExpression, j, k, len1, len2, method, properties, pushSlice, ref1, start;
         this.ctor = null;
         this.boundMethods = [];
         executableBody = null;
         initializer = [];
-        expressions = this.body.expressions;
+        ({expressions} = this.body);
         i = 0;
-        ref3 = expressions.slice();
-        for (j = 0, len1 = ref3.length; j < len1; j++) {
-          expression = ref3[j];
+        ref1 = expressions.slice();
+        for (j = 0, len1 = ref1.length; j < len1; j++) {
+          expression = ref1[j];
           if (expression instanceof Value && expression.isObject(true)) {
-            properties = expression.base.properties;
+            ({properties} = expression.base);
             exprs = [];
             end = 0;
             start = 0;
@@ -1794,7 +1873,10 @@
 
       addInitializerMethod(assign) {
         var method, methodName, variable;
-        variable = assign.variable, method = assign.value;
+        ({
+          variable,
+          value: method
+        } = assign);
         method.isMethod = true;
         method.isStatic = variable.looksStatic(this.name);
         if (method.isStatic) {
@@ -1832,11 +1914,11 @@
       proxyBoundMethods(o) {
         var name;
         this.ctor.thisAssignments = (function() {
-          var j, ref3, results;
-          ref3 = this.boundMethods;
+          var j, ref1, results;
+          ref1 = this.boundMethods;
           results = [];
-          for (j = ref3.length - 1; j >= 0; j += -1) {
-            name = ref3[j];
+          for (j = ref1.length - 1; j >= 0; j += -1) {
+            name = ref1[j];
             name = new Value(new ThisLiteral, [name]).compile(o);
             results.push(new Literal(`${name} = ${utility('bind', o)}(${name}, this)`));
           }
@@ -1862,14 +1944,14 @@
       }
 
       compileNode(o) {
-        var args, argumentsNode, directives, externalCtor, ident, jumpNode, klass, params, parent, ref3, wrapper;
+        var args, argumentsNode, directives, externalCtor, ident, jumpNode, klass, params, parent, ref1, wrapper;
         if (jumpNode = this.body.jumps()) {
           jumpNode.error('Class bodies cannot contain pure statements');
         }
         if (argumentsNode = this.body.contains(isLiteralArguments)) {
           argumentsNode.error("Class bodies shouldn't reference arguments");
         }
-        this.name = (ref3 = this["class"].name) != null ? ref3 : this.defaultClassVariableName;
+        this.name = (ref1 = this["class"].name) != null ? ref1 : this.defaultClassVariableName;
         directives = this.walkBody();
         this.setContext();
         ident = new IdentifierLiteral(this.name);
@@ -1917,15 +1999,15 @@
           }
         }
         this.traverseChildren(false, (child) => {
-          var cont, i, j, len1, node, ref3;
+          var cont, i, j, len1, node, ref1;
           if (child instanceof Class || child instanceof HoistTarget) {
             return false;
           }
           cont = true;
           if (child instanceof Block) {
-            ref3 = child.expressions;
-            for (i = j = 0, len1 = ref3.length; j < len1; i = ++j) {
-              node = ref3[i];
+            ref1 = child.expressions;
+            for (i = j = 0, len1 = ref1.length; j < len1; i = ++j) {
+              node = ref1[i];
               if (node instanceof Value && node.isObject(true)) {
                 cont = false;
                 child.expressions[i] = this.addProperties(node.base.properties);
@@ -2030,7 +2112,7 @@
 
   exports.ImportDeclaration = ImportDeclaration = class ImportDeclaration extends ModuleDeclaration {
     compileNode(o) {
-      var code, ref3;
+      var code, ref1;
       this.checkScope(o, 'import');
       o.importedSymbols = [];
       code = [];
@@ -2038,7 +2120,7 @@
       if (this.clause != null) {
         code.push(...this.clause.compileNode(o));
       }
-      if (((ref3 = this.source) != null ? ref3.value : void 0) != null) {
+      if (((ref1 = this.source) != null ? ref1.value : void 0) != null) {
         if (this.clause !== null) {
           code.push(this.makeCode(' from '));
         }
@@ -2083,7 +2165,7 @@
 
   exports.ExportDeclaration = ExportDeclaration = class ExportDeclaration extends ModuleDeclaration {
     compileNode(o) {
-      var code, ref3;
+      var code, ref1;
       this.checkScope(o, 'export');
       code = [];
       code.push(this.makeCode(`${this.tab}export `));
@@ -2102,7 +2184,7 @@
       } else {
         code = code.concat(this.clause.compileNode(o));
       }
-      if (((ref3 = this.source) != null ? ref3.value : void 0) != null) {
+      if (((ref1 = this.source) != null ? ref1.value : void 0) != null) {
         code.push(this.makeCode(` from ${this.source.value}`));
       }
       code.push(this.makeCode(';'));
@@ -2129,11 +2211,11 @@
         code = [];
         o.indent += TAB;
         compiledList = (function() {
-          var j, len1, ref3, results;
-          ref3 = this.specifiers;
+          var j, len1, ref1, results;
+          ref1 = this.specifiers;
           results = [];
-          for (j = 0, len1 = ref3.length; j < len1; j++) {
-            specifier = ref3[j];
+          for (j = 0, len1 = ref1.length; j < len1; j++) {
+            specifier = ref1[j];
             results.push(specifier.compileToFragments(o, LEVEL_LIST));
           }
           return results;
@@ -2201,8 +2283,8 @@
     }
 
     compileNode(o) {
-      var ref3;
-      if ((ref3 = this.identifier, indexOf.call(o.importedSymbols, ref3) >= 0) || o.scope.check(this.identifier)) {
+      var ref1;
+      if ((ref1 = this.identifier, indexOf.call(o.importedSymbols, ref1) >= 0) || o.scope.check(this.identifier)) {
         this.error(`'${this.identifier}' has already been declared`);
       } else {
         o.importedSymbols.push(this.identifier);
@@ -2230,7 +2312,7 @@
         this.variable = variable1;
         this.value = value1;
         this.context = context1;
-        this.param = options.param, this.subpattern = options.subpattern, this.operatorToken = options.operatorToken, this.moduleDeclaration = options.moduleDeclaration;
+        ({param: this.param, subpattern: this.subpattern, operatorToken: this.operatorToken, moduleDeclaration: this.moduleDeclaration} = options);
       }
 
       isStatement(o) {
@@ -2252,76 +2334,82 @@
       }
 
       compileNode(o) {
-        var answer, compiledName, isValue, j, name, properties, prototype, ref3, ref4, ref5, ref6, ref7, ref8, val, varBase;
+        var answer, compiledName, isValue, j, name, properties, prototype, ref1, ref2, ref3, ref4, ref5, ref6, val, varBase;
         if (isValue = this.variable instanceof Value) {
           if (this.variable.isArray() || this.variable.isObject()) {
-            return this.compilePatternMatch(o);
+            if (!this.variable.isAssignable()) {
+              return this.compilePatternMatch(o);
+            }
           }
           if (this.variable.isSplice()) {
             return this.compileSplice(o);
           }
-          if ((ref3 = this.context) === '||=' || ref3 === '&&=' || ref3 === '?=') {
+          if ((ref1 = this.context) === '||=' || ref1 === '&&=' || ref1 === '?=') {
             return this.compileConditional(o);
           }
-          if ((ref4 = this.context) === '**=' || ref4 === '//=' || ref4 === '%%=') {
+          if ((ref2 = this.context) === '**=' || ref2 === '//=' || ref2 === '%%=') {
             return this.compileSpecialMath(o);
           }
         }
-        if (this.value instanceof Code) {
-          if (this.value.isStatic) {
-            this.value.name = this.variable.properties[0];
-          } else if (((ref5 = this.variable.properties) != null ? ref5.length : void 0) >= 2) {
-            ref6 = this.variable.properties, properties = 3 <= ref6.length ? slice.call(ref6, 0, j = ref6.length - 2) : (j = 0, []), prototype = ref6[j++], name = ref6[j++];
-            if (((ref7 = prototype.name) != null ? ref7.value : void 0) === 'prototype') {
-              this.value.name = name;
-            }
-          }
-        }
         if (!this.context) {
           varBase = this.variable.unwrapAll();
           if (!varBase.isAssignable()) {
             this.variable.error(`'${this.variable.compile(o)}' can't be assigned`);
           }
-          if (!(typeof varBase.hasProperties === "function" ? varBase.hasProperties() : void 0)) {
+          varBase.eachName((name) => {
+            var message;
+            if (typeof name.hasProperties === "function" ? name.hasProperties() : void 0) {
+              return;
+            }
+            if (message = isUnassignable(name.value)) {
+              name.error(message);
+            }
             if (this.moduleDeclaration) {
-              this.checkAssignability(o, varBase);
-              o.scope.add(varBase.value, this.moduleDeclaration);
+              this.checkAssignability(o, name);
+              return o.scope.add(name.value, this.moduleDeclaration);
             } else if (this.param) {
-              o.scope.add(varBase.value, 'var');
+              return o.scope.add(name.value, 'var');
             } else {
-              this.checkAssignability(o, varBase);
-              o.scope.find(varBase.value);
+              this.checkAssignability(o, name);
+              return o.scope.find(name.value);
+            }
+          });
+        }
+        if (this.value instanceof Code) {
+          if (this.value.isStatic) {
+            this.value.name = this.variable.properties[0];
+          } else if (((ref3 = this.variable.properties) != null ? ref3.length : void 0) >= 2) {
+            ref4 = this.variable.properties, properties = 3 <= ref4.length ? slice.call(ref4, 0, j = ref4.length - 2) : (j = 0, []), prototype = ref4[j++], name = ref4[j++];
+            if (((ref5 = prototype.name) != null ? ref5.value : void 0) === 'prototype') {
+              this.value.name = name;
             }
           }
         }
         val = this.value.compileToFragments(o, LEVEL_LIST);
-        if (isValue && this.variable.base instanceof Obj) {
-          this.variable.front = true;
-        }
         compiledName = this.variable.compileToFragments(o, LEVEL_LIST);
         if (this.context === 'object') {
           if (this.variable.shouldCache()) {
             compiledName.unshift(this.makeCode('['));
             compiledName.push(this.makeCode(']'));
-          } else if (ref8 = fragmentsToText(compiledName), indexOf.call(JS_FORBIDDEN, ref8) >= 0) {
+          } else if (ref6 = fragmentsToText(compiledName), indexOf.call(JS_FORBIDDEN, ref6) >= 0) {
             compiledName.unshift(this.makeCode('"'));
             compiledName.push(this.makeCode('"'));
           }
           return compiledName.concat(this.makeCode(": "), val);
         }
         answer = compiledName.concat(this.makeCode(` ${this.context || '='} `), val);
-        if (o.level <= LEVEL_LIST) {
-          return answer;
-        } else {
+        if (o.level > LEVEL_LIST || (isValue && this.variable.base instanceof Obj)) {
           return this.wrapInBraces(answer);
+        } else {
+          return answer;
         }
       }
 
       compilePatternMatch(o) {
-        var acc, assigns, code, defaultValue, expandedIdx, fragments, i, idx, isObject, ivar, j, len1, message, name, obj, objects, olen, ref, ref3, ref4, ref5, ref6, rest, top, val, value, vvar, vvarText;
+        var acc, assigns, code, defaultValue, expandedIdx, fragments, i, idx, isObject, ivar, j, len1, message, name, obj, objects, olen, ref, rest, top, val, value, vvar, vvarText;
         top = o.level === LEVEL_TOP;
-        value = this.value;
-        objects = this.variable.base.objects;
+        ({value} = this);
+        ({objects} = this.variable.base);
         if (!(olen = objects.length)) {
           code = value.compileToFragments(o);
           if (o.level >= LEVEL_OP) {
@@ -2330,7 +2418,7 @@
             return code;
           }
         }
-        obj = objects[0];
+        [obj] = objects;
         if (olen === 1 && obj instanceof Expansion) {
           obj.error('Destructuring assignment has no target');
         }
@@ -2338,7 +2426,12 @@
         if (top && olen === 1 && !(obj instanceof Splat)) {
           defaultValue = null;
           if (obj instanceof Assign && obj.context === 'object') {
-            ref3 = obj, (ref4 = ref3.variable, idx = ref4.base), obj = ref3.value;
+            ({
+              variable: {
+                base: idx
+              },
+              value: obj
+            } = obj);
             if (obj instanceof Assign) {
               defaultValue = obj.value;
               obj = obj.variable;
@@ -2410,7 +2503,12 @@
             }
             defaultValue = null;
             if (obj instanceof Assign && obj.context === 'object') {
-              ref5 = obj, (ref6 = ref5.variable, idx = ref6.base), obj = ref5.value;
+              ({
+                variable: {
+                  base: idx
+                },
+                value: obj
+              } = obj);
               if (obj instanceof Assign) {
                 defaultValue = obj.value;
                 obj = obj.variable;
@@ -2452,8 +2550,8 @@
       }
 
       compileConditional(o) {
-        var fragments, left, ref3, right;
-        ref3 = this.variable.cacheReference(o), left = ref3[0], right = ref3[1];
+        var fragments, left, right;
+        [left, right] = this.variable.cacheReference(o);
         if (!left.properties.length && left.base instanceof Literal && !(left.base instanceof ThisLiteral) && !o.scope.check(left.base.value)) {
           this.variable.error(`the variable \"${left.base.value}\" can't be assigned with ${this.context} because it has not been declared before`);
         }
@@ -2473,17 +2571,19 @@
       }
 
       compileSpecialMath(o) {
-        var left, ref3, right;
-        ref3 = this.variable.cacheReference(o), left = ref3[0], right = ref3[1];
+        var left, right;
+        [left, right] = this.variable.cacheReference(o);
         return new Assign(left, new Op(this.context.slice(0, -1), right, this.value)).compileToFragments(o);
       }
 
       compileSplice(o) {
-        var answer, exclusive, from, fromDecl, fromRef, name, ref3, ref4, ref5, to, valDef, valRef;
-        ref3 = this.variable.properties.pop().range, from = ref3.from, to = ref3.to, exclusive = ref3.exclusive;
+        var answer, exclusive, from, fromDecl, fromRef, name, to, valDef, valRef;
+        ({
+          range: {from, to, exclusive}
+        } = this.variable.properties.pop());
         name = this.variable.compile(o);
         if (from) {
-          ref4 = this.cacheToCodeFragments(from.cache(o, LEVEL_OP)), fromDecl = ref4[0], fromRef = ref4[1];
+          [fromDecl, fromRef] = this.cacheToCodeFragments(from.cache(o, LEVEL_OP));
         } else {
           fromDecl = fromRef = '0';
         }
@@ -2502,7 +2602,7 @@
         } else {
           to = "9e9";
         }
-        ref5 = this.value.cache(o, LEVEL_LIST), valDef = ref5[0], valRef = ref5[1];
+        [valDef, valRef] = this.value.cache(o, LEVEL_LIST);
         answer = [].concat(this.makeCode(`[].splice.apply(${name}, [${fromDecl}, ${to}].concat(`), valDef, this.makeCode(")), "), valRef);
         if (o.level > LEVEL_TOP) {
           return this.wrapInBraces(answer);
@@ -2551,7 +2651,7 @@
       }
 
       compileNode(o) {
-        var answer, body, condition, exprs, haveBodyParam, haveSplatParam, i, ifTrue, j, k, len1, len2, m, methodScope, modifiers, name, param, paramNames, params, paramsAfterSplat, ref, ref3, ref4, ref5, ref6, ref7, ref8, signature, splatParamName, thisAssignments, wasEmpty;
+        var answer, body, condition, exprs, haveBodyParam, haveSplatParam, i, ifTrue, j, k, len1, len2, m, methodScope, modifiers, name, param, paramNames, params, paramsAfterSplat, ref, ref1, ref2, ref3, ref4, ref5, signature, splatParamName, thisAssignments, wasEmpty;
         if (this.ctor) {
           if (this.isAsync) {
             this.name.error('Class constructor may not be async');
@@ -2561,7 +2661,7 @@
           }
         }
         if (this.bound) {
-          if ((ref3 = o.scope.method) != null ? ref3.bound : void 0) {
+          if ((ref1 = o.scope.method) != null ? ref1.bound : void 0) {
             this.context = o.scope.method.context;
           }
           if (!this.context) {
@@ -2575,7 +2675,7 @@
         delete o.isExistentialEquals;
         params = [];
         exprs = [];
-        thisAssignments = (ref4 = (ref5 = this.thisAssignments) != null ? ref5.slice() : void 0) != null ? ref4 : [];
+        thisAssignments = (ref2 = (ref3 = this.thisAssignments) != null ? ref3.slice() : void 0) != null ? ref2 : [];
         paramsAfterSplat = [];
         haveSplatParam = false;
         haveBodyParam = false;
@@ -2596,9 +2696,9 @@
             return thisAssignments.push(new Assign(node, target));
           }
         });
-        ref6 = this.params;
-        for (i = j = 0, len1 = ref6.length; j < len1; i = ++j) {
-          param = ref6[i];
+        ref4 = this.params;
+        for (i = j = 0, len1 = ref4.length; j < len1; i = ++j) {
+          param = ref4[i];
           if (param.splat || param instanceof Expansion) {
             if (haveSplatParam) {
               param.error('only one splat or expansion parameter is allowed per function definition');
@@ -2610,7 +2710,7 @@
               params.push(ref = param.asReference(o));
               splatParamName = fragmentsToText(ref.compileNode(o));
               if (param.shouldCache()) {
-                exprs.push(new Assign(new Value(param.name), ref, '=', {
+                exprs.push(new Assign(new Value(param.name), ref, null, {
                   param: true
                 }));
               }
@@ -2625,12 +2725,12 @@
               haveBodyParam = true;
               if (param.value != null) {
                 condition = new Op('==', param, new UndefinedLiteral);
-                ifTrue = new Assign(new Value(param.name), param.value, '=', {
+                ifTrue = new Assign(new Value(param.name), param.value, null, {
                   param: true
                 });
                 exprs.push(new If(condition, ifTrue));
               } else {
-                exprs.push(new Assign(new Value(param.name), param.asReference(o), '=', {
+                exprs.push(new Assign(new Value(param.name), param.asReference(o), null, {
                   param: true
                 }));
               }
@@ -2640,7 +2740,7 @@
                 ref = param.asReference(o);
               } else {
                 if ((param.value != null) && !param.assignedInBody) {
-                  ref = new Assign(new Value(param.name), param.value, '=');
+                  ref = new Assign(new Value(param.name), param.value);
                 } else {
                   ref = param;
                 }
@@ -2651,10 +2751,10 @@
               paramsAfterSplat.push(param);
               if ((param.value != null) && !param.shouldCache()) {
                 condition = new Op('==', param, new UndefinedLiteral);
-                ifTrue = new Assign(new Value(param.name), param.value, '=');
+                ifTrue = new Assign(new Value(param.name), param.value);
                 exprs.push(new If(condition, ifTrue));
               }
-              if (((ref7 = param.name) != null ? ref7.value : void 0) != null) {
+              if (((ref5 = param.name) != null ? ref5.value : void 0) != null) {
                 o.scope.add(param.name.value, 'var', true);
               }
             }
@@ -2709,7 +2809,7 @@
           body = this.body.compileWithDeclarations(o);
         }
         if (this.isMethod) {
-          ref8 = [o.scope, o.scope.parent], methodScope = ref8[0], o.scope = ref8[1];
+          [methodScope, o.scope] = [o.scope, o.scope.parent];
           name = this.name.compileToFragments(o);
           if (name[0].code === '.') {
             name.shift();
@@ -2751,11 +2851,11 @@
       }
 
       eachParamName(iterator) {
-        var j, len1, param, ref3, results;
-        ref3 = this.params;
+        var j, len1, param, ref1, results;
+        ref1 = this.params;
         results = [];
-        for (j = 0, len1 = ref3.length; j < len1; j++) {
-          param = ref3[j];
+        for (j = 0, len1 = ref1.length; j < len1; j++) {
+          param = ref1[j];
           results.push(param.eachName(iterator));
         }
         return results;
@@ -2776,7 +2876,7 @@
       }
 
       expandCtorSuper(thisAssignments) {
-        var haveThisParam, param, ref3, seenSuper;
+        var haveThisParam, param, ref1, seenSuper;
         if (!this.ctor) {
           return false;
         }
@@ -2789,7 +2889,7 @@
           }
           return superCall.expressions = thisAssignments;
         });
-        haveThisParam = thisAssignments.length && thisAssignments.length !== ((ref3 = this.thisAssignments) != null ? ref3.length : void 0);
+        haveThisParam = thisAssignments.length && thisAssignments.length !== ((ref1 = this.thisAssignments) != null ? ref1.length : void 0);
         if (this.ctor === 'derived' && !seenSuper && haveThisParam) {
           param = thisAssignments[0].variable;
           param.error("Can't use @params in derived class constructors without calling super");
@@ -2869,7 +2969,7 @@
       }
 
       eachName(iterator, name = this.name) {
-        var atParam, j, len1, node, obj, ref3, ref4;
+        var atParam, j, len1, node, obj, ref1, ref2;
         atParam = (obj) => {
           return iterator(`@${obj.properties[0].name.value}`, obj, this);
         };
@@ -2879,9 +2979,9 @@
         if (name instanceof Value) {
           return atParam(name);
         }
-        ref4 = (ref3 = name.objects) != null ? ref3 : [];
-        for (j = 0, len1 = ref4.length; j < len1; j++) {
-          obj = ref4[j];
+        ref2 = (ref1 = name.objects) != null ? ref1 : [];
+        for (j = 0, len1 = ref2.length; j < len1; j++) {
+          obj = ref2[j];
           if (obj instanceof Assign && (obj.context == null)) {
             obj = obj.variable;
           }
@@ -2937,6 +3037,10 @@
 
   exports.Splat = Splat = (function() {
     class Splat extends Base {
+      isAssignable() {
+        return this.name.isAssignable() && (!this.name.isAtomic || this.name.isAtomic());
+      }
+
       constructor(name) {
         super();
         this.name = name.compile ? name : new Literal(name);
@@ -2958,8 +3062,6 @@
 
     Splat.prototype.children = ['name'];
 
-    Splat.prototype.isAssignable = YES;
-
     return Splat;
 
   })();
@@ -3010,7 +3112,7 @@
 
       jumps() {
         var expressions, j, jumpNode, len1, node;
-        expressions = this.body.expressions;
+        ({expressions} = this.body);
         if (!expressions.length) {
           return false;
         }
@@ -3029,7 +3131,7 @@
         var answer, body, rvar, set;
         o.indent += TAB;
         set = '';
-        body = this.body;
+        ({body} = this);
         if (body.isEmpty()) {
           body = this.makeCode('');
         } else {
@@ -3093,8 +3195,8 @@
       }
 
       isNumber() {
-        var ref3;
-        return this.isUnary() && ((ref3 = this.operator) === '+' || ref3 === '-') && this.first instanceof Value && this.first.isNumber();
+        var ref1;
+        return this.isUnary() && ((ref1 = this.operator) === '+' || ref1 === '-') && this.first instanceof Value && this.first.isNumber();
       }
 
       isAwait() {
@@ -3102,8 +3204,8 @@
       }
 
       isYield() {
-        var ref3;
-        return (ref3 = this.operator) === 'yield' || ref3 === 'yield*';
+        var ref1;
+        return (ref1 = this.operator) === 'yield' || ref1 === 'yield*';
       }
 
       isUnary() {
@@ -3115,12 +3217,12 @@
       }
 
       isChainable() {
-        var ref3;
-        return (ref3 = this.operator) === '<' || ref3 === '>' || ref3 === '>=' || ref3 === '<=' || ref3 === '===' || ref3 === '!==';
+        var ref1;
+        return (ref1 = this.operator) === '<' || ref1 === '>' || ref1 === '>=' || ref1 === '<=' || ref1 === '===' || ref1 === '!==';
       }
 
       invert() {
-        var allInvertable, curr, fst, op, ref3;
+        var allInvertable, curr, fst, op, ref1;
         if (this.isChainable() && this.first.isChainable()) {
           allInvertable = true;
           curr = this;
@@ -3146,7 +3248,7 @@
           return this;
         } else if (this.second) {
           return new Parens(this).invert();
-        } else if (this.operator === '!' && (fst = this.first.unwrap()) instanceof Op && ((ref3 = fst.operator) === '!' || ref3 === 'in' || ref3 === 'instanceof')) {
+        } else if (this.operator === '!' && (fst = this.first.unwrap()) instanceof Op && ((ref1 = fst.operator) === '!' || ref1 === 'in' || ref1 === 'instanceof')) {
           return fst;
         } else {
           return new Op('!', this);
@@ -3154,17 +3256,17 @@
       }
 
       unfoldSoak(o) {
-        var ref3;
-        return ((ref3 = this.operator) === '++' || ref3 === '--' || ref3 === 'delete') && unfoldSoak(o, this, 'first');
+        var ref1;
+        return ((ref1 = this.operator) === '++' || ref1 === '--' || ref1 === 'delete') && unfoldSoak(o, this, 'first');
       }
 
       generateDo(exp) {
-        var call, func, j, len1, param, passedParams, ref, ref3;
+        var call, func, j, len1, param, passedParams, ref, ref1;
         passedParams = [];
         func = exp instanceof Assign && (ref = exp.value.unwrap()) instanceof Code ? ref : exp;
-        ref3 = func.params || [];
-        for (j = 0, len1 = ref3.length; j < len1; j++) {
-          param = ref3[j];
+        ref1 = func.params || [];
+        for (j = 0, len1 = ref1.length; j < len1; j++) {
+          param = ref1[j];
           if (param.value) {
             passedParams.push(param.value);
             delete param.value;
@@ -3178,7 +3280,7 @@
       }
 
       compileNode(o) {
-        var answer, isChain, lhs, message, ref3, rhs;
+        var answer, isChain, lhs, message, ref1, rhs;
         isChain = this.isChainable() && this.first.isChainable();
         if (!isChain) {
           this.first.front = this.front;
@@ -3186,7 +3288,7 @@
         if (this.operator === 'delete' && o.scope.check(this.first.unwrapAll().value)) {
           this.error('delete operand may not be argument or var');
         }
-        if ((ref3 = this.operator) === '--' || ref3 === '++') {
+        if ((ref1 = this.operator) === '--' || ref1 === '++') {
           message = isUnassignable(this.first.unwrapAll().value);
           if (message) {
             this.first.error(message);
@@ -3223,8 +3325,8 @@
       }
 
       compileChain(o) {
-        var fragments, fst, ref3, shared;
-        ref3 = this.first.second.cache(o), this.first.second = ref3[0], shared = ref3[1];
+        var fragments, fst, shared;
+        [this.first.second, shared] = this.first.second.cache(o);
         fst = this.first.compileToFragments(o, LEVEL_OP);
         fragments = fst.concat(this.makeCode(` ${(this.invert ? '&&' : '||')} `), shared.compileToFragments(o), this.makeCode(` ${this.operator} `), this.second.compileToFragments(o, LEVEL_OP));
         return this.wrapInBraces(fragments);
@@ -3271,13 +3373,13 @@
       }
 
       compileContinuation(o) {
-        var op, parts, ref3, ref4;
+        var op, parts, ref1, ref2;
         parts = [];
         op = this.operator;
         if (o.scope.parent == null) {
           this.error(`${this.operator} can only occur inside functions`);
         }
-        if (((ref3 = o.scope.method) != null ? ref3.bound : void 0) && o.scope.method.isGenerator) {
+        if (((ref1 = o.scope.method) != null ? ref1.bound : void 0) && o.scope.method.isGenerator) {
           this.error('yield cannot occur inside bound (fat arrow) functions');
         }
         if (indexOf.call(Object.keys(this.first), 'expression') >= 0 && !(this.first instanceof Throw)) {
@@ -3289,7 +3391,7 @@
             parts.push([this.makeCode("(")]);
           }
           parts.push([this.makeCode(op)]);
-          if (((ref4 = this.first.base) != null ? ref4.value : void 0) !== '') {
+          if (((ref2 = this.first.base) != null ? ref2.value : void 0) !== '') {
             parts.push([this.makeCode(" ")]);
           }
           parts.push(this.first.compileToFragments(o, LEVEL_OP));
@@ -3353,11 +3455,11 @@
       }
 
       compileNode(o) {
-        var hasSplat, j, len1, obj, ref3;
+        var hasSplat, j, len1, obj, ref1;
         if (this.array instanceof Value && this.array.isArray() && this.array.base.objects.length) {
-          ref3 = this.array.base.objects;
-          for (j = 0, len1 = ref3.length; j < len1; j++) {
-            obj = ref3[j];
+          ref1 = this.array.base.objects;
+          for (j = 0, len1 = ref1.length; j < len1; j++) {
+            obj = ref1[j];
             if (!(obj instanceof Splat)) {
               continue;
             }
@@ -3372,13 +3474,13 @@
       }
 
       compileOrTest(o) {
-        var cmp, cnj, i, item, j, len1, ref, ref3, ref4, ref5, sub, tests;
-        ref3 = this.object.cache(o, LEVEL_OP), sub = ref3[0], ref = ref3[1];
-        ref4 = this.negated ? [' !== ', ' && '] : [' === ', ' || '], cmp = ref4[0], cnj = ref4[1];
+        var cmp, cnj, i, item, j, len1, ref, ref1, sub, tests;
+        [sub, ref] = this.object.cache(o, LEVEL_OP);
+        [cmp, cnj] = this.negated ? [' !== ', ' && '] : [' === ', ' || '];
         tests = [];
-        ref5 = this.array.base.objects;
-        for (i = j = 0, len1 = ref5.length; j < len1; i = ++j) {
-          item = ref5[i];
+        ref1 = this.array.base.objects;
+        for (i = j = 0, len1 = ref1.length; j < len1; i = ++j) {
+          item = ref1[i];
           if (i) {
             tests.push(this.makeCode(cnj));
           }
@@ -3392,8 +3494,8 @@
       }
 
       compileLoopTest(o) {
-        var fragments, ref, ref3, sub;
-        ref3 = this.object.cache(o, LEVEL_LIST), sub = ref3[0], ref = ref3[1];
+        var fragments, ref, sub;
+        [sub, ref] = this.object.cache(o, LEVEL_LIST);
         fragments = [].concat(this.makeCode(utility('indexOf', o) + ".call("), this.array.compileToFragments(o, LEVEL_LIST), this.makeCode(", "), ref, this.makeCode(") " + (this.negated ? '< 0' : '>= 0')));
         if (fragmentsToText(sub) === fragmentsToText(ref)) {
           return fragments;
@@ -3431,8 +3533,8 @@
       }
 
       jumps(o) {
-        var ref3;
-        return this.attempt.jumps(o) || ((ref3 = this.recovery) != null ? ref3.jumps(o) : void 0);
+        var ref1;
+        return this.attempt.jumps(o) || ((ref1 = this.recovery) != null ? ref1.jumps(o) : void 0);
       }
 
       makeReturn(res) {
@@ -3501,11 +3603,11 @@
       }
 
       compileNode(o) {
-        var cmp, cnj, code, ref3;
+        var cmp, cnj, code;
         this.expression.front = this.front;
         code = this.expression.compile(o, LEVEL_OP);
         if (this.expression.unwrap() instanceof IdentifierLiteral && !o.scope.check(code)) {
-          ref3 = this.negated ? ['===', '||'] : ['!==', '&&'], cmp = ref3[0], cnj = ref3[1];
+          [cmp, cnj] = this.negated ? ['===', '||'] : ['!==', '&&'];
           code = `typeof ${code} ${cmp} \"undefined\" ${cnj} ${code} ${cmp} null`;
         } else {
           code = `${code} ${(this.negated ? '==' : '!=')} null`;
@@ -3626,9 +3728,9 @@
   exports.For = For = (function() {
     class For extends While {
       constructor(body, source) {
-        var ref3;
+        var ref1, ref2;
         super();
-        this.source = source.source, this.guard = source.guard, this.step = source.step, this.name = source.name, this.index = source.index;
+        ({source: this.source, guard: this.guard, step: this.step, name: this.name, index: this.index} = source);
         this.body = Block.wrap([body]);
         this.own = !!source.own;
         this.object = !!source.object;
@@ -3640,9 +3742,9 @@
           source.ownTag.error(`cannot use own with for-${(this.from ? 'from' : 'in')}`);
         }
         if (this.object) {
-          ref3 = [this.index, this.name], this.name = ref3[0], this.index = ref3[1];
+          [this.name, this.index] = [this.index, this.name];
         }
-        if (this.index instanceof Value && !this.index.isAssignable()) {
+        if (((ref1 = this.index) != null ? typeof ref1.isArray === "function" ? ref1.isArray() : void 0 : void 0) || ((ref2 = this.index) != null ? typeof ref2.isObject === "function" ? ref2.isObject() : void 0 : void 0)) {
           this.index.error('index cannot be a pattern matching expression');
         }
         this.range = this.source instanceof Value && this.source.base instanceof Range && !this.source.properties.length && !this.from;
@@ -3657,9 +3759,9 @@
       }
 
       compileNode(o) {
-        var body, bodyFragments, compare, compareDown, declare, declareDown, defPart, defPartFragments, down, forPartFragments, guardPart, idt1, increment, index, ivar, kvar, kvarAssign, last, lvar, name, namePart, ref, ref3, ref4, resultPart, returnResult, rvar, scope, source, step, stepNum, stepVar, svar, varPart;
+        var body, bodyFragments, compare, compareDown, declare, declareDown, defPart, defPartFragments, down, forPartFragments, guardPart, idt1, increment, index, ivar, kvar, kvarAssign, last, lvar, name, namePart, ref, ref1, resultPart, returnResult, rvar, scope, source, step, stepNum, stepVar, svar, varPart;
         body = Block.wrap([this.body]);
-        ref3 = body.expressions, last = ref3[ref3.length - 1];
+        ref1 = body.expressions, last = ref1[ref1.length - 1];
         if ((last != null ? last.jumps() : void 0) instanceof Return) {
           this.returns = false;
         }
@@ -3692,7 +3794,7 @@
         kvar = ((this.range || this.from) && name) || index || ivar;
         kvarAssign = kvar !== ivar ? `${kvar} = ` : "";
         if (this.step && !this.range) {
-          ref4 = this.cacheToCodeFragments(this.step.cache(o, LEVEL_LIST, shouldCacheOrIsAssignable)), step = ref4[0], stepVar = ref4[1];
+          [step, stepVar] = this.cacheToCodeFragments(this.step.cache(o, LEVEL_LIST, shouldCacheOrIsAssignable));
           if (this.step.isNumber()) {
             stepNum = Number(stepVar);
           }
@@ -3707,7 +3809,7 @@
         if (this.range) {
           forPartFragments = source.compileToFragments(merge(o, {
             index: ivar,
-            name: name,
+            name,
             step: this.step,
             shouldCache: shouldCacheOrIsAssignable
           }));
@@ -3788,24 +3890,24 @@
       }
 
       pluckDirectCall(o, body) {
-        var base, defs, expr, fn, idx, j, len1, ref, ref3, ref4, ref5, ref6, ref7, ref8, ref9, val;
+        var base, defs, expr, fn, idx, j, len1, ref, ref1, ref2, ref3, ref4, ref5, ref6, val;
         defs = [];
-        ref3 = body.expressions;
-        for (idx = j = 0, len1 = ref3.length; j < len1; idx = ++j) {
-          expr = ref3[idx];
+        ref1 = body.expressions;
+        for (idx = j = 0, len1 = ref1.length; j < len1; idx = ++j) {
+          expr = ref1[idx];
           expr = expr.unwrapAll();
           if (!(expr instanceof Call)) {
             continue;
           }
-          val = (ref4 = expr.variable) != null ? ref4.unwrapAll() : void 0;
-          if (!((val instanceof Code) || (val instanceof Value && ((ref5 = val.base) != null ? ref5.unwrapAll() : void 0) instanceof Code && val.properties.length === 1 && ((ref6 = (ref7 = val.properties[0].name) != null ? ref7.value : void 0) === 'call' || ref6 === 'apply')))) {
+          val = (ref2 = expr.variable) != null ? ref2.unwrapAll() : void 0;
+          if (!((val instanceof Code) || (val instanceof Value && ((ref3 = val.base) != null ? ref3.unwrapAll() : void 0) instanceof Code && val.properties.length === 1 && ((ref4 = (ref5 = val.properties[0].name) != null ? ref5.value : void 0) === 'call' || ref4 === 'apply')))) {
             continue;
           }
-          fn = ((ref8 = val.base) != null ? ref8.unwrapAll() : void 0) || val;
+          fn = ((ref6 = val.base) != null ? ref6.unwrapAll() : void 0) || val;
           ref = new IdentifierLiteral(o.scope.freeVariable('fn'));
           base = new Value(ref);
           if (val.base) {
-            ref9 = [base, val], val.base = ref9[0], base = ref9[1];
+            [val.base, base] = [base, val];
           }
           body.expressions[idx] = new Call(base, expr.args);
           defs = defs.concat(this.makeCode(this.tab), new Assign(ref, fn).compileToFragments(o, LEVEL_TOP), this.makeCode(';\n'));
@@ -3833,44 +3935,44 @@
       jumps(o = {
           block: true
         }) {
-        var block, conds, j, jumpNode, len1, ref3, ref4, ref5;
-        ref3 = this.cases;
-        for (j = 0, len1 = ref3.length; j < len1; j++) {
-          ref4 = ref3[j], conds = ref4[0], block = ref4[1];
+        var block, conds, j, jumpNode, len1, ref1, ref2;
+        ref1 = this.cases;
+        for (j = 0, len1 = ref1.length; j < len1; j++) {
+          [conds, block] = ref1[j];
           if (jumpNode = block.jumps(o)) {
             return jumpNode;
           }
         }
-        return (ref5 = this.otherwise) != null ? ref5.jumps(o) : void 0;
+        return (ref2 = this.otherwise) != null ? ref2.jumps(o) : void 0;
       }
 
       makeReturn(res) {
-        var j, len1, pair, ref3, ref4;
-        ref3 = this.cases;
-        for (j = 0, len1 = ref3.length; j < len1; j++) {
-          pair = ref3[j];
+        var j, len1, pair, ref1, ref2;
+        ref1 = this.cases;
+        for (j = 0, len1 = ref1.length; j < len1; j++) {
+          pair = ref1[j];
           pair[1].makeReturn(res);
         }
         if (res) {
           this.otherwise || (this.otherwise = new Block([new Literal('void 0')]));
         }
-        if ((ref4 = this.otherwise) != null) {
-          ref4.makeReturn(res);
+        if ((ref2 = this.otherwise) != null) {
+          ref2.makeReturn(res);
         }
         return this;
       }
 
       compileNode(o) {
-        var block, body, cond, conditions, expr, fragments, i, idt1, idt2, j, k, len1, len2, ref3, ref4, ref5;
+        var block, body, cond, conditions, expr, fragments, i, idt1, idt2, j, k, len1, len2, ref1, ref2;
         idt1 = o.indent + TAB;
         idt2 = o.indent = idt1 + TAB;
         fragments = [].concat(this.makeCode(this.tab + "switch ("), (this.subject ? this.subject.compileToFragments(o, LEVEL_PAREN) : this.makeCode("false")), this.makeCode(") {\n"));
-        ref3 = this.cases;
-        for (i = j = 0, len1 = ref3.length; j < len1; i = ++j) {
-          ref4 = ref3[i], conditions = ref4[0], block = ref4[1];
-          ref5 = flatten([conditions]);
-          for (k = 0, len2 = ref5.length; k < len2; k++) {
-            cond = ref5[k];
+        ref1 = this.cases;
+        for (i = j = 0, len1 = ref1.length; j < len1; i = ++j) {
+          [conditions, block] = ref1[i];
+          ref2 = flatten([conditions]);
+          for (k = 0, len2 = ref2.length; k < len2; k++) {
+            cond = ref2[k];
             if (!this.subject) {
               cond = cond.invert();
             }
@@ -3913,17 +4015,17 @@
         this.condition = options.type === 'unless' ? condition.invert() : condition;
         this.elseBody = null;
         this.isChain = false;
-        this.soak = options.soak;
+        ({soak: this.soak} = options);
       }
 
       bodyNode() {
-        var ref3;
-        return (ref3 = this.body) != null ? ref3.unwrap() : void 0;
+        var ref1;
+        return (ref1 = this.body) != null ? ref1.unwrap() : void 0;
       }
 
       elseBodyNode() {
-        var ref3;
-        return (ref3 = this.elseBody) != null ? ref3.unwrap() : void 0;
+        var ref1;
+        return (ref1 = this.elseBody) != null ? ref1.unwrap() : void 0;
       }
 
       addElse(elseBody) {
@@ -3938,13 +4040,13 @@
       }
 
       isStatement(o) {
-        var ref3;
-        return (o != null ? o.level : void 0) === LEVEL_TOP || this.bodyNode().isStatement(o) || ((ref3 = this.elseBodyNode()) != null ? ref3.isStatement(o) : void 0);
+        var ref1;
+        return (o != null ? o.level : void 0) === LEVEL_TOP || this.bodyNode().isStatement(o) || ((ref1 = this.elseBodyNode()) != null ? ref1.isStatement(o) : void 0);
       }
 
       jumps(o) {
-        var ref3;
-        return this.body.jumps(o) || ((ref3 = this.elseBody) != null ? ref3.jumps(o) : void 0);
+        var ref1;
+        return this.body.jumps(o) || ((ref1 = this.elseBody) != null ? ref1.jumps(o) : void 0);
       }
 
       compileNode(o) {
@@ -3983,9 +4085,7 @@
         }
         indent = o.indent + TAB;
         cond = this.condition.compileToFragments(o, LEVEL_PAREN);
-        body = this.ensureBlock(this.body).compileToFragments(merge(o, {
-          indent: indent
-        }));
+        body = this.ensureBlock(this.body).compileToFragments(merge(o, {indent}));
         ifPart = [].concat(this.makeCode("if ("), cond, this.makeCode(") {\n"), body, this.makeCode(`\n${this.tab}}`));
         if (!child) {
           ifPart.unshift(this.makeCode(this.tab));
@@ -3998,9 +4098,7 @@
           o.chainChild = true;
           answer = answer.concat(this.elseBody.unwrap().compileToFragments(o, LEVEL_TOP));
         } else {
-          answer = answer.concat(this.makeCode("{\n"), this.elseBody.compileToFragments(merge(o, {
-            indent: indent
-          }), LEVEL_TOP), this.makeCode(`\n${this.tab}}`));
+          answer = answer.concat(this.makeCode("{\n"), this.elseBody.compileToFragments(merge(o, {indent}), LEVEL_TOP), this.makeCode(`\n${this.tab}}`));
         }
         return answer;
       }
@@ -4069,7 +4167,7 @@
 
   utility = function(name, o) {
     var ref, root;
-    root = o.scope.root;
+    ({root} = o.scope);
     if (name in root.utilities) {
       return root.utilities[name];
     } else {
diff --git a/lib/coffeescript/optparse.js b/lib/coffeescript/optparse.js
index 79cb367ddf..dbd707953f 100644
--- a/lib/coffeescript/optparse.js
+++ b/lib/coffeescript/optparse.js
@@ -2,7 +2,7 @@
 (function() {
   var LONG_FLAG, MULTI_FLAG, OPTIONAL, OptionParser, SHORT_FLAG, buildRule, buildRules, normalizeArguments, repeat;
 
-  repeat = require('./helpers').repeat;
+  ({repeat} = require('./helpers'));
 
   exports.OptionParser = OptionParser = class OptionParser {
     constructor(rules, banner) {
diff --git a/lib/coffeescript/register.js b/lib/coffeescript/register.js
index 4338790fe2..bc759db22a 100644
--- a/lib/coffeescript/register.js
+++ b/lib/coffeescript/register.js
@@ -48,7 +48,7 @@
   }
 
   if (child_process) {
-    fork = child_process.fork;
+    ({fork} = child_process);
     binary = require.resolve('../../bin/coffee');
     child_process.fork = function(path, args, options) {
       if (helpers.isCoffee(path)) {
diff --git a/lib/coffeescript/repl.js b/lib/coffeescript/repl.js
index a277a44101..0c299bedf0 100644
--- a/lib/coffeescript/repl.js
+++ b/lib/coffeescript/repl.js
@@ -1,6 +1,6 @@
 // Generated by CoffeeScript 2.0.0-alpha1
 (function() {
-  var CoffeeScript, addHistory, addMultilineHandler, fs, getCommandId, merge, nodeREPL, path, ref, replDefaults, runInContext, updateSyntaxError, vm;
+  var CoffeeScript, addHistory, addMultilineHandler, fs, getCommandId, merge, nodeREPL, path, replDefaults, runInContext, updateSyntaxError, vm;
 
   fs = require('fs');
 
@@ -12,18 +12,18 @@
 
   CoffeeScript = require('./coffeescript');
 
-  ref = require('./helpers'), merge = ref.merge, updateSyntaxError = ref.updateSyntaxError;
+  ({merge, updateSyntaxError} = require('./helpers'));
 
   replDefaults = {
     prompt: 'coffee> ',
     historyFile: process.env.HOME ? path.join(process.env.HOME, '.coffee_history') : void 0,
     historyMaxInputSize: 10240,
     "eval": function(input, context, filename, cb) {
-      var Assign, Block, Literal, Value, ast, err, js, ref1, referencedVars, token, tokens;
+      var Assign, Block, Literal, Value, ast, err, js, referencedVars, token, tokens;
       input = input.replace(/\uFF00/g, '\n');
       input = input.replace(/^\(([\s\S]*)\n\)$/m, '$1');
       input = input.replace(/^\s*try\s*{([\s\S]*)}\s*catch.*$/m, '$1');
-      ref1 = require('./nodes'), Block = ref1.Block, Assign = ref1.Assign, Value = ref1.Value, Literal = ref1.Literal;
+      ({Block, Assign, Value, Literal} = require('./nodes'));
       try {
         tokens = CoffeeScript.tokens(input);
         referencedVars = (function() {
@@ -42,7 +42,7 @@
         js = ast.compile({
           bare: true,
           locals: Object.keys(context),
-          referencedVars: referencedVars
+          referencedVars
         });
         return cb(null, runInContext(js, context, filename));
       } catch (error) {
@@ -62,9 +62,9 @@
   };
 
   addMultilineHandler = function(repl) {
-    var inputStream, multiline, nodeLineListener, origPrompt, outputStream, ref1, rli;
-    rli = repl.rli, inputStream = repl.inputStream, outputStream = repl.outputStream;
-    origPrompt = (ref1 = repl._prompt) != null ? ref1 : repl.prompt;
+    var inputStream, multiline, nodeLineListener, origPrompt, outputStream, ref, rli;
+    ({rli, inputStream, outputStream} = repl);
+    origPrompt = (ref = repl._prompt) != null ? ref : repl.prompt;
     multiline = {
       enabled: false,
       initialPrompt: origPrompt.replace(/^[^> ]*/, function(x) {
@@ -168,10 +168,10 @@
 
   module.exports = {
     start: function(opts = {}) {
-      var build, major, minor, ref1, repl;
-      ref1 = process.versions.node.split('.').map(function(n) {
+      var build, major, minor, repl;
+      [major, minor, build] = process.versions.node.split('.').map(function(n) {
         return parseInt(n);
-      }), major = ref1[0], minor = ref1[1], build = ref1[2];
+      });
       if (major < 6) {
         console.warn("Node 6+ required for CoffeeScript REPL");
         process.exit(1);
diff --git a/lib/coffeescript/rewriter.js b/lib/coffeescript/rewriter.js
index c3d7384d41..938da10920 100644
--- a/lib/coffeescript/rewriter.js
+++ b/lib/coffeescript/rewriter.js
@@ -1,6 +1,6 @@
 // Generated by CoffeeScript 2.0.0-alpha1
 (function() {
-  var BALANCED_PAIRS, CALL_CLOSERS, EXPRESSION_CLOSE, EXPRESSION_END, EXPRESSION_START, IMPLICIT_CALL, IMPLICIT_END, IMPLICIT_FUNC, IMPLICIT_UNSPACED_CALL, INVERSES, LINEBREAKS, SINGLE_CLOSERS, SINGLE_LINERS, generate, k, left, len, ref, rite,
+  var BALANCED_PAIRS, CALL_CLOSERS, EXPRESSION_CLOSE, EXPRESSION_END, EXPRESSION_START, IMPLICIT_CALL, IMPLICIT_END, IMPLICIT_FUNC, IMPLICIT_UNSPACED_CALL, INVERSES, LINEBREAKS, SINGLE_CLOSERS, SINGLE_LINERS, generate, k, left, len, rite,
     indexOf = [].indexOf || function(item) { for (var i = 0, l = this.length; i < l; i++) { if (i in this && this[i] === item) return i; } return -1; };
 
   generate = function(tag, value, origin) {
@@ -30,7 +30,7 @@
 
       scanTokens(block) {
         var i, token, tokens;
-        tokens = this.tokens;
+        ({tokens} = this);
         i = 0;
         while (token = tokens[i]) {
           i += block.call(this, token, i, tokens);
@@ -40,7 +40,7 @@
 
       detectEnd(i, condition, action) {
         var levels, ref, ref1, token, tokens;
-        tokens = this.tokens;
+        ({tokens} = this);
         levels = 0;
         while (token = tokens[i]) {
           if (levels === 0 && condition.call(this, token, i)) {
@@ -63,7 +63,7 @@
         var i, k, len, ref, tag;
         ref = this.tokens;
         for (i = k = 0, len = ref.length; k < len; i = ++k) {
-          tag = ref[i][0];
+          [tag] = ref[i];
           if (tag !== 'TERMINATOR') {
             break;
           }
@@ -168,10 +168,10 @@
         stack = [];
         start = null;
         return this.scanTokens(function(token, i, tokens) {
-          var endImplicitCall, endImplicitObject, forward, inImplicit, inImplicitCall, inImplicitControl, inImplicitObject, newLine, nextTag, offset, prevTag, prevToken, ref, ref1, ref2, ref3, ref4, ref5, s, sameLine, stackIdx, stackTag, stackTop, startIdx, startImplicitCall, startImplicitObject, startsLine, tag;
-          tag = token[0];
-          prevTag = (prevToken = i > 0 ? tokens[i - 1] : [])[0];
-          nextTag = (i < tokens.length - 1 ? tokens[i + 1] : [])[0];
+          var endImplicitCall, endImplicitObject, forward, inImplicit, inImplicitCall, inImplicitControl, inImplicitObject, newLine, nextTag, offset, prevTag, prevToken, ref, ref1, ref2, s, sameLine, stackIdx, stackTag, stackTop, startIdx, startImplicitCall, startImplicitObject, startsLine, tag;
+          [tag] = token;
+          [prevTag] = prevToken = i > 0 ? tokens[i - 1] : [];
+          [nextTag] = i < tokens.length - 1 ? tokens[i + 1] : [];
           stackTop = function() {
             return stack[stack.length - 1];
           };
@@ -302,7 +302,7 @@
             this.insideForDeclaration = nextTag === 'FOR';
             startsLine = s === 0 || (ref2 = this.tag(s - 1), indexOf.call(LINEBREAKS, ref2) >= 0) || tokens[s - 1].newLine;
             if (stackTop()) {
-              ref3 = stackTop(), stackTag = ref3[0], stackIdx = ref3[1];
+              [stackTag, stackIdx] = stackTop();
               if ((stackTag === '{' || stackTag === 'INDENT' && this.tag(stackIdx - 1) === '{') && (startsLine || this.tag(s - 1) === ',' || this.tag(s - 1) === '{')) {
                 return forward(1);
               }
@@ -316,7 +316,7 @@
           newLine = prevTag === 'OUTDENT' || prevToken.newLine;
           if (indexOf.call(IMPLICIT_END, tag) >= 0 || indexOf.call(CALL_CLOSERS, tag) >= 0 && newLine) {
             while (inImplicit()) {
-              ref4 = stackTop(), stackTag = ref4[0], stackIdx = ref4[1], (ref5 = ref4[2], sameLine = ref5.sameLine, startsLine = ref5.startsLine);
+              [stackTag, stackIdx, {sameLine, startsLine}] = stackTop();
               if (inImplicitCall() && prevTag !== ',') {
                 endImplicitCall();
               } else if (inImplicitObject() && !this.insideForDeclaration && sameLine && tag !== 'TERMINATOR' && prevTag !== ':') {
@@ -351,9 +351,15 @@
             return 1;
           }
           if (token[0] === '{' && (nextLocation = (ref = tokens[i + 1]) != null ? ref[2] : void 0)) {
-            line = nextLocation.first_line, column = nextLocation.first_column;
+            ({
+              first_line: line,
+              first_column: column
+            } = nextLocation);
           } else if (prevLocation = (ref1 = tokens[i - 1]) != null ? ref1[2] : void 0) {
-            line = prevLocation.last_line, column = prevLocation.last_column;
+            ({
+              last_line: line,
+              last_column: column
+            } = prevLocation);
           } else {
             line = column = 0;
           }
@@ -395,8 +401,8 @@
           return this.tokens.splice((this.tag(i - 1) === ',' ? i - 1 : i), 0, outdent);
         };
         return this.scanTokens(function(token, i, tokens) {
-          var j, k, ref, ref1, ref2, tag;
-          tag = token[0];
+          var j, k, ref, ref1, tag;
+          [tag] = token;
           if (tag === 'TERMINATOR') {
             if (this.tag(i + 1) === 'ELSE' && this.tag(i - 1) !== 'OUTDENT') {
               tokens.splice(i, 1, ...this.indentation());
@@ -418,7 +424,7 @@
           }
           if (indexOf.call(SINGLE_LINERS, tag) >= 0 && this.tag(i + 1) !== 'INDENT' && !(tag === 'ELSE' && this.tag(i + 1) === 'IF')) {
             starter = tag;
-            ref2 = this.indentation(tokens[i]), indent = ref2[0], outdent = ref2[1];
+            [indent, outdent] = this.indentation(tokens[i]);
             if (starter === 'THEN') {
               indent.fromThen = true;
             }
@@ -438,8 +444,8 @@
         original = null;
         condition = function(token, i) {
           var prevTag, tag;
-          tag = token[0];
-          prevTag = this.tokens[i - 1][0];
+          [tag] = token;
+          [prevTag] = this.tokens[i - 1];
           return tag === 'TERMINATOR' || (tag === 'INDENT' && indexOf.call(SINGLE_LINERS, prevTag) < 0);
         };
         action = function(token, i) {
@@ -492,7 +498,7 @@
   EXPRESSION_END = [];
 
   for (k = 0, len = BALANCED_PAIRS.length; k < len; k++) {
-    ref = BALANCED_PAIRS[k], left = ref[0], rite = ref[1];
+    [left, rite] = BALANCED_PAIRS[k];
     EXPRESSION_START.push(INVERSES[rite] = left);
     EXPRESSION_END.push(INVERSES[left] = rite);
   }
diff --git a/lib/coffeescript/scope.js b/lib/coffeescript/scope.js
index c8e823ca31..87a4938443 100644
--- a/lib/coffeescript/scope.js
+++ b/lib/coffeescript/scope.js
@@ -30,10 +30,7 @@
       if (Object.prototype.hasOwnProperty.call(this.positions, name)) {
         return this.variables[this.positions[name]].type = type;
       } else {
-        return this.positions[name] = this.variables.push({
-          name: name,
-          type: type
-        }) - 1;
+        return this.positions[name] = this.variables.push({name, type}) - 1;
       }
     }
 
@@ -110,7 +107,7 @@
 
     assign(name, value) {
       this.add(name, {
-        value: value,
+        value,
         assigned: true
       }, true);
       return this.hasAssignments = true;
diff --git a/lib/coffeescript/sourcemap.js b/lib/coffeescript/sourcemap.js
index 60d5fe2c68..659fb5cd20 100644
--- a/lib/coffeescript/sourcemap.js
+++ b/lib/coffeescript/sourcemap.js
@@ -9,8 +9,8 @@
     }
 
     add(column, arg, options) {
-      var sourceColumn, sourceLine;
-      sourceLine = arg[0], sourceColumn = arg[1];
+      var options, sourceColumn, sourceLine;
+      [sourceLine, sourceColumn] = arg;
       if (options === void 0) {
         options = {};
       }
@@ -19,9 +19,9 @@
       }
       return this.columns[column] = {
         line: this.line,
-        column: column,
-        sourceLine: sourceLine,
-        sourceColumn: sourceColumn
+        column,
+        sourceLine,
+        sourceColumn
       };
     }
 
@@ -45,14 +45,14 @@
 
       add(sourceLocation, generatedLocation, options = {}) {
         var base, column, line, lineMap;
-        line = generatedLocation[0], column = generatedLocation[1];
+        [line, column] = generatedLocation;
         lineMap = ((base = this.lines)[line] || (base[line] = new LineMap(line)));
         return lineMap.add(column, sourceLocation, options);
       }
 
       sourceLocation(arg) {
         var column, line, lineMap;
-        line = arg[0], column = arg[1];
+        [line, column] = arg;
         while (!((lineMap = this.lines[line]) || (line <= 0))) {
           line--;
         }
diff --git a/src/nodes.coffee b/src/nodes.coffee
index cc2a6dabc7..5f55de8d69 100644
--- a/src/nodes.coffee
+++ b/src/nodes.coffee
@@ -543,6 +543,9 @@ exports.PassthroughLiteral = class PassthroughLiteral extends Literal
 exports.IdentifierLiteral = class IdentifierLiteral extends Literal
   isAssignable: YES
 
+  eachName: (iterator) ->
+    iterator @
+
 exports.PropertyName = class PropertyName extends Literal
   isAssignable: YES
 
@@ -740,6 +743,14 @@ exports.Value = class Value extends Base
         return new If new Existence(fst), snd, soak: on
       no
 
+  eachName: (iterator) ->
+    if @hasProperties()
+      iterator @
+    else if @base.isAssignable()
+      @base.eachName iterator
+    else
+      @error 'tried to assign to unassignable value'
+
 #### Comment
 
 # CoffeeScript passes through block comments as JavaScript block comments
@@ -1104,6 +1115,12 @@ exports.Obj = class Obj extends Base
 
   children: ['properties']
 
+  isAssignable: ->
+    for prop in @properties
+      prop = prop.value if prop instanceof Assign
+      return false unless prop.isAssignable()
+    true
+
   compileNode: (o) ->
     props = @properties
     if @generated
@@ -1111,16 +1128,22 @@ exports.Obj = class Obj extends Base
         node.error 'cannot have an implicit value in an implicit object'
     idt        = o.indent += TAB
     lastNoncom = @lastNonComment @properties
+
+    isCompact = true
+    isCompact = false for prop in @properties when prop instanceof Assign or prop instanceof Comment
+
     answer = []
-    answer.push @makeCode "{#{if props.length is 0 then '}' else '\n'}"
+    answer.push @makeCode "{#{if isCompact then '' else '\n'}"
     for prop, i in props
       join = if i is props.length - 1
         ''
+      else if isCompact
+        ', '
       else if prop is lastNoncom or prop instanceof Comment
         '\n'
       else
         ',\n'
-      indent = if prop instanceof Comment then '' else idt
+      indent = if isCompact or prop instanceof Comment then '' else idt
       if prop instanceof Assign
         if prop.context isnt 'object'
           prop.operatorToken.error "unexpected #{prop.operatorToken.value}"
@@ -1133,18 +1156,24 @@ exports.Obj = class Obj extends Base
           [key, value] = prop.base.cache o
           key  = new PropertyName key.value if key instanceof IdentifierLiteral
           prop = new Assign key, value, 'object'
-        else
+        else if not prop.bareLiteral?(IdentifierLiteral)
           prop = new Assign prop, prop, 'object'
       if indent then answer.push @makeCode indent
       answer.push prop.compileToFragments(o, LEVEL_TOP)...
       if join then answer.push @makeCode join
-    answer.push @makeCode "\n#{@tab}}" unless props.length is 0
+    answer.push @makeCode "#{if isCompact then '' else "\n#{@tab}"}}"
     if @front then @wrapInBraces answer else answer
 
   assigns: (name) ->
     for prop in @properties when prop.assigns name then return yes
     no
 
+  eachName: (iterator) ->
+    for prop in @properties
+      prop = prop.value if prop instanceof Assign
+      prop = prop.unwrapAll()
+      prop.eachName iterator
+
 #### Arr
 
 # An array literal.
@@ -1156,6 +1185,14 @@ exports.Arr = class Arr extends Base
 
   children: ['objects']
 
+  isAssignable: ->
+    return false unless @objects.length
+
+    for obj, i in @objects
+      return false if obj instanceof Splat and i + 1 != @objects.length
+      return false unless obj.isAssignable() and (not obj.isAtomic or obj.isAtomic())
+    true
+
   compileNode: (o) ->
     return [@makeCode '[]'] unless @objects.length
     o.indent += TAB
@@ -1178,6 +1215,11 @@ exports.Arr = class Arr extends Base
     for obj in @objects when obj.assigns name then return yes
     no
 
+  eachName: (iterator) ->
+    for obj in @objects
+      obj = obj.unwrapAll()
+      obj.eachName iterator
+
 #### Class
 
 # The CoffeeScript class definition.
@@ -1660,33 +1702,41 @@ exports.Assign = class Assign extends Base
   # has not been seen yet within the current scope, declare it.
   compileNode: (o) ->
     if isValue = @variable instanceof Value
-      return @compilePatternMatch o if @variable.isArray() or @variable.isObject()
+      if @variable.isArray() or @variable.isObject()
+        return @compilePatternMatch o unless @variable.isAssignable()
+
       return @compileSplice       o if @variable.isSplice()
       return @compileConditional  o if @context in ['||=', '&&=', '?=']
       return @compileSpecialMath  o if @context in ['**=', '//=', '%%=']
-    if @value instanceof Code
-      if @value.isStatic
-        @value.name = @variable.properties[0]
-      else if @variable.properties?.length >= 2
-        [properties..., prototype, name] = @variable.properties
-        @value.name = name if prototype.name?.value is 'prototype'
+
     unless @context
       varBase = @variable.unwrapAll()
       unless varBase.isAssignable()
         @variable.error "'#{@variable.compile o}' can't be assigned"
-      unless varBase.hasProperties?()
+
+      varBase.eachName (name) =>
+        return if name.hasProperties?()
+
+        name.error message if message = isUnassignable name.value
+
         # `moduleDeclaration` can be `'import'` or `'export'`
         if @moduleDeclaration
-          @checkAssignability o, varBase
-          o.scope.add varBase.value, @moduleDeclaration
+          @checkAssignability o, name
+          o.scope.add name.value, @moduleDeclaration
         else if @param
-          o.scope.add varBase.value, 'var'
+          o.scope.add name.value, 'var'
         else
-          @checkAssignability o, varBase
-          o.scope.find varBase.value
+          @checkAssignability o, name
+          o.scope.find name.value
+
+    if @value instanceof Code
+      if @value.isStatic
+        @value.name = @variable.properties[0]
+      else if @variable.properties?.length >= 2
+        [properties..., prototype, name] = @variable.properties
+        @value.name = name if prototype.name?.value is 'prototype'
 
     val = @value.compileToFragments o, LEVEL_LIST
-    @variable.front = true if isValue and @variable.base instanceof Obj
     compiledName = @variable.compileToFragments o, LEVEL_LIST
 
     if @context is 'object'
@@ -1699,7 +1749,7 @@ exports.Assign = class Assign extends Base
       return compiledName.concat @makeCode(": "), val
 
     answer = compiledName.concat @makeCode(" #{ @context or '=' } "), val
-    if o.level <= LEVEL_LIST then answer else @wrapInBraces answer
+    if o.level > LEVEL_LIST or (isValue and @variable.base instanceof Obj) then @wrapInBraces answer else answer
 
   # Brief implementation of recursive pattern matching, when assigning array or
   # object literals to a value. Peeks at their properties to assign inner names.
@@ -1950,7 +2000,7 @@ exports.Code = class Code extends Base
           params.push ref = param.asReference o
           splatParamName = fragmentsToText ref.compileNode o
           if param.shouldCache()
-            exprs.push new Assign new Value(param.name), ref, '=', param: yes
+            exprs.push new Assign new Value(param.name), ref, null, param: yes
             # TODO: output destructured parameters as is, and fix destructuring
             # of objects with default values to work in this context (see
             # Obj.compileNode `if prop.context isnt 'object'`).
@@ -1973,10 +2023,10 @@ exports.Code = class Code extends Base
           # `(arg) => { var a = arg.a; }`, with a default value if it has one.
           if param.value?
             condition = new Op '==', param, new UndefinedLiteral
-            ifTrue = new Assign new Value(param.name), param.value, '=', param: yes
+            ifTrue = new Assign new Value(param.name), param.value, null, param: yes
             exprs.push new If condition, ifTrue
           else
-            exprs.push new Assign new Value(param.name), param.asReference(o), '=', param: yes
+            exprs.push new Assign new Value(param.name), param.asReference(o), null, param: yes
 
         # If this parameter comes before the splat or expansion, it will go
         # in the function definition parameter list.
@@ -1989,7 +2039,7 @@ exports.Code = class Code extends Base
             ref = param.asReference o
           else
             if param.value? and not param.assignedInBody
-              ref = new Assign new Value(param.name), param.value, '='
+              ref = new Assign new Value(param.name), param.value
             else
               ref = param
           # Add this parameter’s reference to the function scope
@@ -2002,7 +2052,7 @@ exports.Code = class Code extends Base
           # (if necessary) as an expression in the body.
           if param.value? and not param.shouldCache()
             condition = new Op '==', param, new UndefinedLiteral
-            ifTrue = new Assign new Value(param.name), param.value, '='
+            ifTrue = new Assign new Value(param.name), param.value
             exprs.push new If condition, ifTrue
           # Add this parameter to the scope, since it wouldn’t have been added yet since it was skipped earlier.
           o.scope.add param.name.value, 'var', yes if param.name?.value?
@@ -2205,7 +2255,8 @@ exports.Splat = class Splat extends Base
 
   children: ['name']
 
-  isAssignable: YES
+  isAssignable: ->
+    @name.isAssignable() and (not @name.isAtomic or @name.isAtomic())
 
   constructor: (name) ->
     super()
@@ -2719,7 +2770,7 @@ exports.For = class For extends While
     @index.error 'cannot use index with for-from' if @from and @index
     source.ownTag.error "cannot use own with for-#{if @from then 'from' else 'in'}" if @own and not @object
     [@name, @index] = [@index, @name] if @object
-    @index.error 'index cannot be a pattern matching expression' if @index instanceof Value and not @index.isAssignable()
+    @index.error 'index cannot be a pattern matching expression' if @index?.isArray?() or @index?.isObject?()
     @range   = @source instanceof Value and @source.base instanceof Range and not @source.properties.length and not @from
     @pattern = @name instanceof Value
     @index.error 'indexes do not apply to range loops' if @range and @index
diff --git a/test/assignment.coffee b/test/assignment.coffee
index aff5371a1d..20c940d700 100644
--- a/test/assignment.coffee
+++ b/test/assignment.coffee
@@ -141,9 +141,6 @@ test "#1192: assignment starting with object literals", ->
 
 # Destructuring Assignment
 
-test "empty destructuring assignment", ->
-  {} = [] = undefined
-
 test "chained destructuring assignments", ->
   [a] = {0: b} = {'0': c} = [nonce={}]
   eq nonce, a