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diff --git a/signaling-server/node_modules/socket.io/node_modules/socket.io-client/node_modules/uglify-js/README.html b/signaling-server/node_modules/socket.io/node_modules/socket.io-client/node_modules/uglify-js/README.html new file mode 100644 index 0000000..5f37ac0 --- /dev/null +++ b/signaling-server/node_modules/socket.io/node_modules/socket.io-client/node_modules/uglify-js/README.html @@ -0,0 +1,981 @@ +<?xml version="1.0" encoding="utf-8"?> +<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" + "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd"> +<html xmlns="http://www.w3.org/1999/xhtml" +lang="en" xml:lang="en"> +<head> +<title>UglifyJS – a JavaScript parser/compressor/beautifier</title> +<meta http-equiv="Content-Type" content="text/html;charset=utf-8"/> +<meta name="generator" content="Org-mode"/> +<meta name="generated" content="2011-12-09 14:59:08 EET"/> +<meta name="author" content="Mihai Bazon"/> +<meta name="description" content="a JavaScript parser/compressor/beautifier in JavaScript"/> +<meta name="keywords" content="javascript, js, parser, compiler, compressor, mangle, minify, minifier"/> +<style type="text/css"> + <!--/*--><![CDATA[/*><!--*/ + html { font-family: Times, serif; font-size: 12pt; } + .title { text-align: center; } + .todo { color: red; } + .done { color: green; } + .tag { background-color: #add8e6; font-weight:normal } + .target { } + .timestamp { color: #bebebe; } + .timestamp-kwd { color: #5f9ea0; } + .right {margin-left:auto; margin-right:0px; text-align:right;} + .left {margin-left:0px; margin-right:auto; text-align:left;} + .center {margin-left:auto; margin-right:auto; text-align:center;} + p.verse { margin-left: 3% } + pre { + border: 1pt solid #AEBDCC; + background-color: #F3F5F7; + padding: 5pt; + font-family: courier, monospace; + font-size: 90%; + overflow:auto; + } + table { border-collapse: collapse; } + td, th { vertical-align: top; } + th.right { text-align:center; } + th.left { text-align:center; } + th.center { text-align:center; } + td.right { text-align:right; } + td.left { text-align:left; } + td.center { text-align:center; } + dt { font-weight: bold; } + div.figure { padding: 0.5em; } + div.figure p { text-align: center; } + div.inlinetask { + padding:10px; + border:2px solid gray; + margin:10px; + background: #ffffcc; + } + textarea { overflow-x: auto; } + .linenr { font-size:smaller } + .code-highlighted {background-color:#ffff00;} + .org-info-js_info-navigation { border-style:none; } + #org-info-js_console-label { font-size:10px; font-weight:bold; + white-space:nowrap; } + .org-info-js_search-highlight {background-color:#ffff00; color:#000000; + font-weight:bold; } + /*]]>*/--> +</style> +<link rel="stylesheet" type="text/css" href="docstyle.css" /> +<script type="text/javascript"> +<!--/*--><![CDATA[/*><!--*/ + function CodeHighlightOn(elem, id) + { + var target = document.getElementById(id); + if(null != target) { + elem.cacheClassElem = elem.className; + elem.cacheClassTarget = target.className; + target.className = "code-highlighted"; + elem.className = "code-highlighted"; + } + } + function CodeHighlightOff(elem, id) + { + var target = document.getElementById(id); + if(elem.cacheClassElem) + elem.className = elem.cacheClassElem; + if(elem.cacheClassTarget) + target.className = elem.cacheClassTarget; + } +/*]]>*///--> +</script> + +</head> +<body> + +<div id="preamble"> + +</div> + +<div id="content"> +<h1 class="title">UglifyJS – a JavaScript parser/compressor/beautifier</h1> + + +<div id="table-of-contents"> +<h2>Table of Contents</h2> +<div id="text-table-of-contents"> +<ul> +<li><a href="#sec-1">1 UglifyJS — a JavaScript parser/compressor/beautifier </a> +<ul> +<li><a href="#sec-1-1">1.1 Unsafe transformations </a> +<ul> +<li><a href="#sec-1-1-1">1.1.1 Calls involving the global Array constructor </a></li> +<li><a href="#sec-1-1-2">1.1.2 <code>obj.toString()</code> ==> <code>obj+“”</code> </a></li> +</ul> +</li> +<li><a href="#sec-1-2">1.2 Install (NPM) </a></li> +<li><a href="#sec-1-3">1.3 Install latest code from GitHub </a></li> +<li><a href="#sec-1-4">1.4 Usage </a> +<ul> +<li><a href="#sec-1-4-1">1.4.1 API </a></li> +<li><a href="#sec-1-4-2">1.4.2 Beautifier shortcoming – no more comments </a></li> +<li><a href="#sec-1-4-3">1.4.3 Use as a code pre-processor </a></li> +</ul> +</li> +<li><a href="#sec-1-5">1.5 Compression – how good is it? </a></li> +<li><a href="#sec-1-6">1.6 Bugs? </a></li> +<li><a href="#sec-1-7">1.7 Links </a></li> +<li><a href="#sec-1-8">1.8 License </a></li> +</ul> +</li> +</ul> +</div> +</div> + +<div id="outline-container-1" class="outline-2"> +<h2 id="sec-1"><span class="section-number-2">1</span> UglifyJS — a JavaScript parser/compressor/beautifier </h2> +<div class="outline-text-2" id="text-1"> + + +<p> +This package implements a general-purpose JavaScript +parser/compressor/beautifier toolkit. It is developed on <a href="http://nodejs.org/">NodeJS</a>, but it +should work on any JavaScript platform supporting the CommonJS module system +(and if your platform of choice doesn't support CommonJS, you can easily +implement it, or discard the <code>exports.*</code> lines from UglifyJS sources). +</p> +<p> +The tokenizer/parser generates an abstract syntax tree from JS code. You +can then traverse the AST to learn more about the code, or do various +manipulations on it. This part is implemented in <a href="../lib/parse-js.js">parse-js.js</a> and it's a +port to JavaScript of the excellent <a href="http://marijn.haverbeke.nl/parse-js/">parse-js</a> Common Lisp library from <a href="http://marijn.haverbeke.nl/">Marijn Haverbeke</a>. +</p> +<p> +( See <a href="http://github.com/mishoo/cl-uglify-js">cl-uglify-js</a> if you're looking for the Common Lisp version of +UglifyJS. ) +</p> +<p> +The second part of this package, implemented in <a href="../lib/process.js">process.js</a>, inspects and +manipulates the AST generated by the parser to provide the following: +</p> +<ul> +<li>ability to re-generate JavaScript code from the AST. Optionally + indented—you can use this if you want to “beautify” a program that has + been compressed, so that you can inspect the source. But you can also run + our code generator to print out an AST without any whitespace, so you + achieve compression as well. + +</li> +<li>shorten variable names (usually to single characters). Our mangler will + analyze the code and generate proper variable names, depending on scope + and usage, and is smart enough to deal with globals defined elsewhere, or + with <code>eval()</code> calls or <code>with{}</code> statements. In short, if <code>eval()</code> or + <code>with{}</code> are used in some scope, then all variables in that scope and any + variables in the parent scopes will remain unmangled, and any references + to such variables remain unmangled as well. + +</li> +<li>various small optimizations that may lead to faster code but certainly + lead to smaller code. Where possible, we do the following: + +<ul> +<li>foo["bar"] ==> foo.bar + +</li> +<li>remove block brackets <code>{}</code> + +</li> +<li>join consecutive var declarations: + var a = 10; var b = 20; ==> var a=10,b=20; + +</li> +<li>resolve simple constant expressions: 1 +2 * 3 ==> 7. We only do the + replacement if the result occupies less bytes; for example 1/3 would + translate to 0.333333333333, so in this case we don't replace it. + +</li> +<li>consecutive statements in blocks are merged into a sequence; in many + cases, this leaves blocks with a single statement, so then we can remove + the block brackets. + +</li> +<li>various optimizations for IF statements: + +<ul> +<li>if (foo) bar(); else baz(); ==> foo?bar():baz(); +</li> +<li>if (!foo) bar(); else baz(); ==> foo?baz():bar(); +</li> +<li>if (foo) bar(); ==> foo&&bar(); +</li> +<li>if (!foo) bar(); ==> foo||bar(); +</li> +<li>if (foo) return bar(); else return baz(); ==> return foo?bar():baz(); +</li> +<li>if (foo) return bar(); else something(); ==> {if(foo)return bar();something()} + +</li> +</ul> + +</li> +<li>remove some unreachable code and warn about it (code that follows a + <code>return</code>, <code>throw</code>, <code>break</code> or <code>continue</code> statement, except + function/variable declarations). + +</li> +<li>act a limited version of a pre-processor (c.f. the pre-processor of + C/C++) to allow you to safely replace selected global symbols with + specified values. When combined with the optimisations above this can + make UglifyJS operate slightly more like a compilation process, in + that when certain symbols are replaced by constant values, entire code + blocks may be optimised away as unreachable. +</li> +</ul> + +</li> +</ul> + + + +</div> + +<div id="outline-container-1-1" class="outline-3"> +<h3 id="sec-1-1"><span class="section-number-3">1.1</span> <span class="target">Unsafe transformations</span> </h3> +<div class="outline-text-3" id="text-1-1"> + + +<p> +The following transformations can in theory break code, although they're +probably safe in most practical cases. To enable them you need to pass the +<code>--unsafe</code> flag. +</p> + +</div> + +<div id="outline-container-1-1-1" class="outline-4"> +<h4 id="sec-1-1-1"><span class="section-number-4">1.1.1</span> Calls involving the global Array constructor </h4> +<div class="outline-text-4" id="text-1-1-1"> + + +<p> +The following transformations occur: +</p> + + + +<pre class="src src-js"><span class="org-keyword">new</span> <span class="org-type">Array</span>(1, 2, 3, 4) => [1,2,3,4] +Array(a, b, c) => [a,b,c] +<span class="org-keyword">new</span> <span class="org-type">Array</span>(5) => Array(5) +<span class="org-keyword">new</span> <span class="org-type">Array</span>(a) => Array(a) +</pre> + + +<p> +These are all safe if the Array name isn't redefined. JavaScript does allow +one to globally redefine Array (and pretty much everything, in fact) but I +personally don't see why would anyone do that. +</p> +<p> +UglifyJS does handle the case where Array is redefined locally, or even +globally but with a <code>function</code> or <code>var</code> declaration. Therefore, in the +following cases UglifyJS <b>doesn't touch</b> calls or instantiations of Array: +</p> + + + +<pre class="src src-js"><span class="org-comment-delimiter">// </span><span class="org-comment">case 1. globally declared variable</span> + <span class="org-keyword">var</span> <span class="org-variable-name">Array</span>; + <span class="org-keyword">new</span> <span class="org-type">Array</span>(1, 2, 3); + Array(a, b); + + <span class="org-comment-delimiter">// </span><span class="org-comment">or (can be declared later)</span> + <span class="org-keyword">new</span> <span class="org-type">Array</span>(1, 2, 3); + <span class="org-keyword">var</span> <span class="org-variable-name">Array</span>; + + <span class="org-comment-delimiter">// </span><span class="org-comment">or (can be a function)</span> + <span class="org-keyword">new</span> <span class="org-type">Array</span>(1, 2, 3); + <span class="org-keyword">function</span> <span class="org-function-name">Array</span>() { ... } + +<span class="org-comment-delimiter">// </span><span class="org-comment">case 2. declared in a function</span> + (<span class="org-keyword">function</span>(){ + a = <span class="org-keyword">new</span> <span class="org-type">Array</span>(1, 2, 3); + b = Array(5, 6); + <span class="org-keyword">var</span> <span class="org-variable-name">Array</span>; + })(); + + <span class="org-comment-delimiter">// </span><span class="org-comment">or</span> + (<span class="org-keyword">function</span>(<span class="org-variable-name">Array</span>){ + <span class="org-keyword">return</span> Array(5, 6, 7); + })(); + + <span class="org-comment-delimiter">// </span><span class="org-comment">or</span> + (<span class="org-keyword">function</span>(){ + <span class="org-keyword">return</span> <span class="org-keyword">new</span> <span class="org-type">Array</span>(1, 2, 3, 4); + <span class="org-keyword">function</span> <span class="org-function-name">Array</span>() { ... } + })(); + + <span class="org-comment-delimiter">// </span><span class="org-comment">etc.</span> +</pre> + + +</div> + +</div> + +<div id="outline-container-1-1-2" class="outline-4"> +<h4 id="sec-1-1-2"><span class="section-number-4">1.1.2</span> <code>obj.toString()</code> ==> <code>obj+“”</code> </h4> +<div class="outline-text-4" id="text-1-1-2"> + + +</div> +</div> + +</div> + +<div id="outline-container-1-2" class="outline-3"> +<h3 id="sec-1-2"><span class="section-number-3">1.2</span> Install (NPM) </h3> +<div class="outline-text-3" id="text-1-2"> + + +<p> +UglifyJS is now available through NPM — <code>npm install uglify-js</code> should do +the job. +</p> +</div> + +</div> + +<div id="outline-container-1-3" class="outline-3"> +<h3 id="sec-1-3"><span class="section-number-3">1.3</span> Install latest code from GitHub </h3> +<div class="outline-text-3" id="text-1-3"> + + + + + +<pre class="src src-sh"><span class="org-comment-delimiter">## </span><span class="org-comment">clone the repository</span> +mkdir -p /where/you/wanna/put/it +<span class="org-builtin">cd</span> /where/you/wanna/put/it +git clone git://github.com/mishoo/UglifyJS.git + +<span class="org-comment-delimiter">## </span><span class="org-comment">make the module available to Node</span> +mkdir -p ~/.node_libraries/ +<span class="org-builtin">cd</span> ~/.node_libraries/ +ln -s /where/you/wanna/put/it/UglifyJS/uglify-js.js + +<span class="org-comment-delimiter">## </span><span class="org-comment">and if you want the CLI script too:</span> +mkdir -p ~/bin +<span class="org-builtin">cd</span> ~/bin +ln -s /where/you/wanna/put/it/UglifyJS/bin/uglifyjs + <span class="org-comment-delimiter"># </span><span class="org-comment">(then add ~/bin to your $PATH if it's not there already)</span> +</pre> + + +</div> + +</div> + +<div id="outline-container-1-4" class="outline-3"> +<h3 id="sec-1-4"><span class="section-number-3">1.4</span> Usage </h3> +<div class="outline-text-3" id="text-1-4"> + + +<p> +There is a command-line tool that exposes the functionality of this library +for your shell-scripting needs: +</p> + + + +<pre class="src src-sh">uglifyjs [ options... ] [ filename ] +</pre> + + +<p> +<code>filename</code> should be the last argument and should name the file from which +to read the JavaScript code. If you don't specify it, it will read code +from STDIN. +</p> +<p> +Supported options: +</p> +<ul> +<li><code>-b</code> or <code>--beautify</code> — output indented code; when passed, additional + options control the beautifier: + +<ul> +<li><code>-i N</code> or <code>--indent N</code> — indentation level (number of spaces) + +</li> +<li><code>-q</code> or <code>--quote-keys</code> — quote keys in literal objects (by default, + only keys that cannot be identifier names will be quotes). + +</li> +</ul> + +</li> +<li><code>--ascii</code> — pass this argument to encode non-ASCII characters as + <code>\uXXXX</code> sequences. By default UglifyJS won't bother to do it and will + output Unicode characters instead. (the output is always encoded in UTF8, + but if you pass this option you'll only get ASCII). + +</li> +<li><code>-nm</code> or <code>--no-mangle</code> — don't mangle names. + +</li> +<li><code>-nmf</code> or <code>--no-mangle-functions</code> – in case you want to mangle variable + names, but not touch function names. + +</li> +<li><code>-ns</code> or <code>--no-squeeze</code> — don't call <code>ast_squeeze()</code> (which does various + optimizations that result in smaller, less readable code). + +</li> +<li><code>-mt</code> or <code>--mangle-toplevel</code> — mangle names in the toplevel scope too + (by default we don't do this). + +</li> +<li><code>--no-seqs</code> — when <code>ast_squeeze()</code> is called (thus, unless you pass + <code>--no-squeeze</code>) it will reduce consecutive statements in blocks into a + sequence. For example, "a = 10; b = 20; foo();" will be written as + "a=10,b=20,foo();". In various occasions, this allows us to discard the + block brackets (since the block becomes a single statement). This is ON + by default because it seems safe and saves a few hundred bytes on some + libs that I tested it on, but pass <code>--no-seqs</code> to disable it. + +</li> +<li><code>--no-dead-code</code> — by default, UglifyJS will remove code that is + obviously unreachable (code that follows a <code>return</code>, <code>throw</code>, <code>break</code> or + <code>continue</code> statement and is not a function/variable declaration). Pass + this option to disable this optimization. + +</li> +<li><code>-nc</code> or <code>--no-copyright</code> — by default, <code>uglifyjs</code> will keep the initial + comment tokens in the generated code (assumed to be copyright information + etc.). If you pass this it will discard it. + +</li> +<li><code>-o filename</code> or <code>--output filename</code> — put the result in <code>filename</code>. If + this isn't given, the result goes to standard output (or see next one). + +</li> +<li><code>--overwrite</code> — if the code is read from a file (not from STDIN) and you + pass <code>--overwrite</code> then the output will be written in the same file. + +</li> +<li><code>--ast</code> — pass this if you want to get the Abstract Syntax Tree instead + of JavaScript as output. Useful for debugging or learning more about the + internals. + +</li> +<li><code>-v</code> or <code>--verbose</code> — output some notes on STDERR (for now just how long + each operation takes). + +</li> +<li><code>-d SYMBOL[=VALUE]</code> or <code>--define SYMBOL[=VALUE]</code> — will replace + all instances of the specified symbol where used as an identifier + (except where symbol has properly declared by a var declaration or + use as function parameter or similar) with the specified value. This + argument may be specified multiple times to define multiple + symbols - if no value is specified the symbol will be replaced with + the value <code>true</code>, or you can specify a numeric value (such as + <code>1024</code>), a quoted string value (such as ="object"= or + ='https://github.com'<code>), or the name of another symbol or keyword (such as =null</code> or <code>document</code>). + This allows you, for example, to assign meaningful names to key + constant values but discard the symbolic names in the uglified + version for brevity/efficiency, or when used wth care, allows + UglifyJS to operate as a form of <b>conditional compilation</b> + whereby defining appropriate values may, by dint of the constant + folding and dead code removal features above, remove entire + superfluous code blocks (e.g. completely remove instrumentation or + trace code for production use). + Where string values are being defined, the handling of quotes are + likely to be subject to the specifics of your command shell + environment, so you may need to experiment with quoting styles + depending on your platform, or you may find the option + <code>--define-from-module</code> more suitable for use. + +</li> +<li><code>-define-from-module SOMEMODULE</code> — will load the named module (as + per the NodeJS <code>require()</code> function) and iterate all the exported + properties of the module defining them as symbol names to be defined + (as if by the <code>--define</code> option) per the name of each property + (i.e. without the module name prefix) and given the value of the + property. This is a much easier way to handle and document groups of + symbols to be defined rather than a large number of <code>--define</code> + options. + +</li> +<li><code>--unsafe</code> — enable other additional optimizations that are known to be + unsafe in some contrived situations, but could still be generally useful. + For now only these: + +<ul> +<li>foo.toString() ==> foo+"" +</li> +<li>new Array(x,…) ==> [x,…] +</li> +<li>new Array(x) ==> Array(x) + +</li> +</ul> + +</li> +<li><code>--max-line-len</code> (default 32K characters) — add a newline after around + 32K characters. I've seen both FF and Chrome croak when all the code was + on a single line of around 670K. Pass –max-line-len 0 to disable this + safety feature. + +</li> +<li><code>--reserved-names</code> — some libraries rely on certain names to be used, as + pointed out in issue #92 and #81, so this option allow you to exclude such + names from the mangler. For example, to keep names <code>require</code> and <code>$super</code> + intact you'd specify –reserved-names "require,$super". + +</li> +<li><code>--inline-script</code> – when you want to include the output literally in an + HTML <code><script></code> tag you can use this option to prevent <code></script</code> from + showing up in the output. + +</li> +<li><code>--lift-vars</code> – when you pass this, UglifyJS will apply the following + transformations (see the notes in API, <code>ast_lift_variables</code>): + +<ul> +<li>put all <code>var</code> declarations at the start of the scope +</li> +<li>make sure a variable is declared only once +</li> +<li>discard unused function arguments +</li> +<li>discard unused inner (named) functions +</li> +<li>finally, try to merge assignments into that one <code>var</code> declaration, if + possible. +</li> +</ul> + +</li> +</ul> + + + +</div> + +<div id="outline-container-1-4-1" class="outline-4"> +<h4 id="sec-1-4-1"><span class="section-number-4">1.4.1</span> API </h4> +<div class="outline-text-4" id="text-1-4-1"> + + +<p> +To use the library from JavaScript, you'd do the following (example for +NodeJS): +</p> + + + +<pre class="src src-js"><span class="org-keyword">var</span> <span class="org-variable-name">jsp</span> = require(<span class="org-string">"uglify-js"</span>).parser; +<span class="org-keyword">var</span> <span class="org-variable-name">pro</span> = require(<span class="org-string">"uglify-js"</span>).uglify; + +<span class="org-keyword">var</span> <span class="org-variable-name">orig_code</span> = <span class="org-string">"... JS code here"</span>; +<span class="org-keyword">var</span> <span class="org-variable-name">ast</span> = jsp.parse(orig_code); <span class="org-comment-delimiter">// </span><span class="org-comment">parse code and get the initial AST</span> +ast = pro.ast_mangle(ast); <span class="org-comment-delimiter">// </span><span class="org-comment">get a new AST with mangled names</span> +ast = pro.ast_squeeze(ast); <span class="org-comment-delimiter">// </span><span class="org-comment">get an AST with compression optimizations</span> +<span class="org-keyword">var</span> <span class="org-variable-name">final_code</span> = pro.gen_code(ast); <span class="org-comment-delimiter">// </span><span class="org-comment">compressed code here</span> +</pre> + + +<p> +The above performs the full compression that is possible right now. As you +can see, there are a sequence of steps which you can apply. For example if +you want compressed output but for some reason you don't want to mangle +variable names, you would simply skip the line that calls +<code>pro.ast_mangle(ast)</code>. +</p> +<p> +Some of these functions take optional arguments. Here's a description: +</p> +<ul> +<li><code>jsp.parse(code, strict_semicolons)</code> – parses JS code and returns an AST. + <code>strict_semicolons</code> is optional and defaults to <code>false</code>. If you pass + <code>true</code> then the parser will throw an error when it expects a semicolon and + it doesn't find it. For most JS code you don't want that, but it's useful + if you want to strictly sanitize your code. + +</li> +<li><code>pro.ast_lift_variables(ast)</code> – merge and move <code>var</code> declarations to the + scop of the scope; discard unused function arguments or variables; discard + unused (named) inner functions. It also tries to merge assignments + following the <code>var</code> declaration into it. + +<p> + If your code is very hand-optimized concerning <code>var</code> declarations, this + lifting variable declarations might actually increase size. For me it + helps out. On jQuery it adds 865 bytes (243 after gzip). YMMV. Also + note that (since it's not enabled by default) this operation isn't yet + heavily tested (please report if you find issues!). +</p> +<p> + Note that although it might increase the image size (on jQuery it gains + 865 bytes, 243 after gzip) it's technically more correct: in certain + situations, dead code removal might drop variable declarations, which + would not happen if the variables are lifted in advance. +</p> +<p> + Here's an example of what it does: +</p></li> +</ul> + + + + + +<pre class="src src-js"><span class="org-keyword">function</span> <span class="org-function-name">f</span>(<span class="org-variable-name">a</span>, <span class="org-variable-name">b</span>, <span class="org-variable-name">c</span>, <span class="org-variable-name">d</span>, <span class="org-variable-name">e</span>) { + <span class="org-keyword">var</span> <span class="org-variable-name">q</span>; + <span class="org-keyword">var</span> <span class="org-variable-name">w</span>; + w = 10; + q = 20; + <span class="org-keyword">for</span> (<span class="org-keyword">var</span> <span class="org-variable-name">i</span> = 1; i < 10; ++i) { + <span class="org-keyword">var</span> <span class="org-variable-name">boo</span> = foo(a); + } + <span class="org-keyword">for</span> (<span class="org-keyword">var</span> <span class="org-variable-name">i</span> = 0; i < 1; ++i) { + <span class="org-keyword">var</span> <span class="org-variable-name">boo</span> = bar(c); + } + <span class="org-keyword">function</span> <span class="org-function-name">foo</span>(){ ... } + <span class="org-keyword">function</span> <span class="org-function-name">bar</span>(){ ... } + <span class="org-keyword">function</span> <span class="org-function-name">baz</span>(){ ... } +} + +<span class="org-comment-delimiter">// </span><span class="org-comment">transforms into ==></span> + +<span class="org-keyword">function</span> <span class="org-function-name">f</span>(<span class="org-variable-name">a</span>, <span class="org-variable-name">b</span>, <span class="org-variable-name">c</span>) { + <span class="org-keyword">var</span> <span class="org-variable-name">i</span>, <span class="org-variable-name">boo</span>, <span class="org-variable-name">w</span> = 10, <span class="org-variable-name">q</span> = 20; + <span class="org-keyword">for</span> (i = 1; i < 10; ++i) { + boo = foo(a); + } + <span class="org-keyword">for</span> (i = 0; i < 1; ++i) { + boo = bar(c); + } + <span class="org-keyword">function</span> <span class="org-function-name">foo</span>() { ... } + <span class="org-keyword">function</span> <span class="org-function-name">bar</span>() { ... } +} +</pre> + + +<ul> +<li><code>pro.ast_mangle(ast, options)</code> – generates a new AST containing mangled + (compressed) variable and function names. It supports the following + options: + +<ul> +<li><code>toplevel</code> – mangle toplevel names (by default we don't touch them). +</li> +<li><code>except</code> – an array of names to exclude from compression. +</li> +<li><code>defines</code> – an object with properties named after symbols to + replace (see the <code>--define</code> option for the script) and the values + representing the AST replacement value. + +</li> +</ul> + +</li> +<li><code>pro.ast_squeeze(ast, options)</code> – employs further optimizations designed + to reduce the size of the code that <code>gen_code</code> would generate from the + AST. Returns a new AST. <code>options</code> can be a hash; the supported options + are: + +<ul> +<li><code>make_seqs</code> (default true) which will cause consecutive statements in a + block to be merged using the "sequence" (comma) operator + +</li> +<li><code>dead_code</code> (default true) which will remove unreachable code. + +</li> +</ul> + +</li> +<li><code>pro.gen_code(ast, options)</code> – generates JS code from the AST. By + default it's minified, but using the <code>options</code> argument you can get nicely + formatted output. <code>options</code> is, well, optional :-) and if you pass it it + must be an object and supports the following properties (below you can see + the default values): + +<ul> +<li><code>beautify: false</code> – pass <code>true</code> if you want indented output +</li> +<li><code>indent_start: 0</code> (only applies when <code>beautify</code> is <code>true</code>) – initial + indentation in spaces +</li> +<li><code>indent_level: 4</code> (only applies when <code>beautify</code> is <code>true</code>) -- + indentation level, in spaces (pass an even number) +</li> +<li><code>quote_keys: false</code> – if you pass <code>true</code> it will quote all keys in + literal objects +</li> +<li><code>space_colon: false</code> (only applies when <code>beautify</code> is <code>true</code>) – wether + to put a space before the colon in object literals +</li> +<li><code>ascii_only: false</code> – pass <code>true</code> if you want to encode non-ASCII + characters as <code>\uXXXX</code>. +</li> +<li><code>inline_script: false</code> – pass <code>true</code> to escape occurrences of + <code></script</code> in strings +</li> +</ul> + +</li> +</ul> + + +</div> + +</div> + +<div id="outline-container-1-4-2" class="outline-4"> +<h4 id="sec-1-4-2"><span class="section-number-4">1.4.2</span> Beautifier shortcoming – no more comments </h4> +<div class="outline-text-4" id="text-1-4-2"> + + +<p> +The beautifier can be used as a general purpose indentation tool. It's +useful when you want to make a minified file readable. One limitation, +though, is that it discards all comments, so you don't really want to use it +to reformat your code, unless you don't have, or don't care about, comments. +</p> +<p> +In fact it's not the beautifier who discards comments — they are dumped at +the parsing stage, when we build the initial AST. Comments don't really +make sense in the AST, and while we could add nodes for them, it would be +inconvenient because we'd have to add special rules to ignore them at all +the processing stages. +</p> +</div> + +</div> + +<div id="outline-container-1-4-3" class="outline-4"> +<h4 id="sec-1-4-3"><span class="section-number-4">1.4.3</span> Use as a code pre-processor </h4> +<div class="outline-text-4" id="text-1-4-3"> + + +<p> +The <code>--define</code> option can be used, particularly when combined with the +constant folding logic, as a form of pre-processor to enable or remove +particular constructions, such as might be used for instrumenting +development code, or to produce variations aimed at a specific +platform. +</p> +<p> +The code below illustrates the way this can be done, and how the +symbol replacement is performed. +</p> + + + +<pre class="src src-js">CLAUSE1: <span class="org-keyword">if</span> (<span class="org-keyword">typeof</span> DEVMODE === <span class="org-string">'undefined'</span>) { + DEVMODE = <span class="org-constant">true</span>; +} + +<span class="org-function-name">CLAUSE2</span>: <span class="org-keyword">function</span> init() { + <span class="org-keyword">if</span> (DEVMODE) { + console.log(<span class="org-string">"init() called"</span>); + } + .... + DEVMODE &amp;&amp; console.log(<span class="org-string">"init() complete"</span>); +} + +<span class="org-function-name">CLAUSE3</span>: <span class="org-keyword">function</span> reportDeviceStatus(<span class="org-variable-name">device</span>) { + <span class="org-keyword">var</span> <span class="org-variable-name">DEVMODE</span> = device.mode, <span class="org-variable-name">DEVNAME</span> = device.name; + <span class="org-keyword">if</span> (DEVMODE === <span class="org-string">'open'</span>) { + .... + } +} +</pre> + + +<p> +When the above code is normally executed, the undeclared global +variable <code>DEVMODE</code> will be assigned the value <b>true</b> (see <code>CLAUSE1</code>) +and so the <code>init()</code> function (<code>CLAUSE2</code>) will write messages to the +console log when executed, but in <code>CLAUSE3</code> a locally declared +variable will mask access to the <code>DEVMODE</code> global symbol. +</p> +<p> +If the above code is processed by UglifyJS with an argument of +<code>--define DEVMODE=false</code> then UglifyJS will replace <code>DEVMODE</code> with the +boolean constant value <b>false</b> within <code>CLAUSE1</code> and <code>CLAUSE2</code>, but it +will leave <code>CLAUSE3</code> as it stands because there <code>DEVMODE</code> resolves to +a validly declared variable. +</p> +<p> +And more so, the constant-folding features of UglifyJS will recognise +that the <code>if</code> condition of <code>CLAUSE1</code> is thus always false, and so will +remove the test and body of <code>CLAUSE1</code> altogether (including the +otherwise slightly problematical statement <code>false = true;</code> which it +will have formed by replacing <code>DEVMODE</code> in the body). Similarly, +within <code>CLAUSE2</code> both calls to <code>console.log()</code> will be removed +altogether. +</p> +<p> +In this way you can mimic, to a limited degree, the functionality of +the C/C++ pre-processor to enable or completely remove blocks +depending on how certain symbols are defined - perhaps using UglifyJS +to generate different versions of source aimed at different +environments +</p> +<p> +It is recommmended (but not made mandatory) that symbols designed for +this purpose are given names consisting of <code>UPPER_CASE_LETTERS</code> to +distinguish them from other (normal) symbols and avoid the sort of +clash that <code>CLAUSE3</code> above illustrates. +</p> +</div> +</div> + +</div> + +<div id="outline-container-1-5" class="outline-3"> +<h3 id="sec-1-5"><span class="section-number-3">1.5</span> Compression – how good is it? </h3> +<div class="outline-text-3" id="text-1-5"> + + +<p> +Here are updated statistics. (I also updated my Google Closure and YUI +installations). +</p> +<p> +We're still a lot better than YUI in terms of compression, though slightly +slower. We're still a lot faster than Closure, and compression after gzip +is comparable. +</p> +<table border="2" cellspacing="0" cellpadding="6" rules="groups" frame="hsides"> +<caption></caption> +<colgroup><col class="left" /><col class="left" /><col class="right" /><col class="left" /><col class="right" /><col class="left" /><col class="right" /> +</colgroup> +<thead> +<tr><th scope="col" class="left">File</th><th scope="col" class="left">UglifyJS</th><th scope="col" class="right">UglifyJS+gzip</th><th scope="col" class="left">Closure</th><th scope="col" class="right">Closure+gzip</th><th scope="col" class="left">YUI</th><th scope="col" class="right">YUI+gzip</th></tr> +</thead> +<tbody> +<tr><td class="left">jquery-1.6.2.js</td><td class="left">91001 (0:01.59)</td><td class="right">31896</td><td class="left">90678 (0:07.40)</td><td class="right">31979</td><td class="left">101527 (0:01.82)</td><td class="right">34646</td></tr> +<tr><td class="left">paper.js</td><td class="left">142023 (0:01.65)</td><td class="right">43334</td><td class="left">134301 (0:07.42)</td><td class="right">42495</td><td class="left">173383 (0:01.58)</td><td class="right">48785</td></tr> +<tr><td class="left">prototype.js</td><td class="left">88544 (0:01.09)</td><td class="right">26680</td><td class="left">86955 (0:06.97)</td><td class="right">26326</td><td class="left">92130 (0:00.79)</td><td class="right">28624</td></tr> +<tr><td class="left">thelib-full.js (DynarchLIB)</td><td class="left">251939 (0:02.55)</td><td class="right">72535</td><td class="left">249911 (0:09.05)</td><td class="right">72696</td><td class="left">258869 (0:01.94)</td><td class="right">76584</td></tr> +</tbody> +</table> + + +</div> + +</div> + +<div id="outline-container-1-6" class="outline-3"> +<h3 id="sec-1-6"><span class="section-number-3">1.6</span> Bugs? </h3> +<div class="outline-text-3" id="text-1-6"> + + +<p> +Unfortunately, for the time being there is no automated test suite. But I +ran the compressor manually on non-trivial code, and then I tested that the +generated code works as expected. A few hundred times. +</p> +<p> +DynarchLIB was started in times when there was no good JS minifier. +Therefore I was quite religious about trying to write short code manually, +and as such DL contains a lot of syntactic hacks<sup><a class="footref" name="fnr.1" href="#fn.1">1</a></sup> such as “foo == bar ? a += 10 : b = 20”, though the more readable version would clearly be to use +“if/else”. +</p> +<p> +Since the parser/compressor runs fine on DL and jQuery, I'm quite confident +that it's solid enough for production use. If you can identify any bugs, +I'd love to hear about them (<a href="http://groups.google.com/group/uglifyjs">use the Google Group</a> or email me directly). +</p> +</div> + +</div> + +<div id="outline-container-1-7" class="outline-3"> +<h3 id="sec-1-7"><span class="section-number-3">1.7</span> Links </h3> +<div class="outline-text-3" id="text-1-7"> + + +<ul> +<li>Twitter: <a href="http://twitter.com/UglifyJS">@UglifyJS</a> +</li> +<li>Project at GitHub: <a href="http://github.com/mishoo/UglifyJS">http://github.com/mishoo/UglifyJS</a> +</li> +<li>Google Group: <a href="http://groups.google.com/group/uglifyjs">http://groups.google.com/group/uglifyjs</a> +</li> +<li>Common Lisp JS parser: <a href="http://marijn.haverbeke.nl/parse-js/">http://marijn.haverbeke.nl/parse-js/</a> +</li> +<li>JS-to-Lisp compiler: <a href="http://github.com/marijnh/js">http://github.com/marijnh/js</a> +</li> +<li>Common Lisp JS uglifier: <a href="http://github.com/mishoo/cl-uglify-js">http://github.com/mishoo/cl-uglify-js</a> +</li> +</ul> + + +</div> + +</div> + +<div id="outline-container-1-8" class="outline-3"> +<h3 id="sec-1-8"><span class="section-number-3">1.8</span> License </h3> +<div class="outline-text-3" id="text-1-8"> + + +<p> +UglifyJS is released under the BSD license: +</p> + + + +<pre class="example">Copyright 2010 (c) Mihai Bazon <mihai.bazon@gmail.com> +Based on parse-js (http://marijn.haverbeke.nl/parse-js/). + +Redistribution and use in source and binary forms, with or without +modification, are permitted provided that the following conditions +are met: + + * Redistributions of source code must retain the above + copyright notice, this list of conditions and the following + disclaimer. + + * Redistributions in binary form must reproduce the above + copyright notice, this list of conditions and the following + disclaimer in the documentation and/or other materials + provided with the distribution. + +THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER “AS IS” AND ANY +EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE +IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR +PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER BE +LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, +OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, +PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR +PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY +THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR +TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF +THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF +SUCH DAMAGE. +</pre> + + +<div id="footnotes"> +<h2 class="footnotes">Footnotes: </h2> +<div id="text-footnotes"> +<p class="footnote"><sup><a class="footnum" name="fn.1" href="#fnr.1">1</a></sup> I even reported a few bugs and suggested some fixes in the original + <a href="http://marijn.haverbeke.nl/parse-js/">parse-js</a> library, and Marijn pushed fixes literally in minutes. +</p></div> +</div> +</div> + +</div> +</div> +</div> + +<div id="postamble"> +<p class="date">Date: 2011-12-09 14:59:08 EET</p> +<p class="author">Author: Mihai Bazon</p> +<p class="creator">Org version 7.7 with Emacs version 23</p> +<a href="http://validator.w3.org/check?uri=referer">Validate XHTML 1.0</a> + +</div> +</body> +</html> |