Consolidate null, Boolean, and String values

Author: RGustBardon

README.org

@@ -187,6 +187,10 @@ Supported options:
   - =-q= or =--quote-keys= --- quote keys in literal objects (by default,
     only keys that cannot be identifier names will be quotes).
 
+- =-c= or =----consolidate-primitive-values= --- consolidates null, Boolean,
+  and String values. Known as aliasing in the Closure Compiler. Worsens the
+  data compression ratio of gzip.
+
 - =--ascii= --- pass this argument to encode non-ASCII characters as
   =\uXXXX= sequences.  By default UglifyJS won't bother to do it and will
   output Unicode characters instead.  (the output is always encoded in UTF8,

bin/uglifyjs

@@ -4,11 +4,13 @@
 global.sys = require(/^v0\.[012]/.test(process.version) ? "sys" : "util");
 var fs = require("fs");
 var uglify = require("uglify-js"), // symlink ~/.node_libraries/uglify-js.js to ../uglify-js.js
+    consolidator = uglify.consolidator,
     jsp = uglify.parser,
     pro = uglify.uglify;
 
 var options = {
         ast: false,
+        consolidate: false,
         mangle: true,
         mangle_toplevel: false,
         no_mangle_functions: false,
@@ -46,6 +48,10 @@ out: while (args.length > 0) {
             case "--beautify":
                 options.codegen_options.beautify = true;
                 break;
+            case "-c":
+            case "--consolidate-primitive-values":
+                options.consolidate = true;
+                break;
             case "-i":
             case "--indent":
                 options.codegen_options.indent_level = args.shift();
@@ -278,6 +284,9 @@ function squeeze_it(code) {
         }
         try {
                 var ast = time_it("parse", function(){ return jsp.parse(code); });
+                if (options.consolidate) ast = time_it("consolidate", function(){
+                        return consolidator.ast_consolidate(ast);
+                });
                 if (options.lift_vars) {
                         ast = time_it("lift", function(){ return pro.ast_lift_variables(ast); });
                 }