Starting destructuring expressions

lib/output.js

@@ -1179,6 +1179,17 @@ function OutputStream(options) {
         var def = self.definition();
         output.print_name(def ? def.mangled_name || def.name : self.name);
     });
+    DEFPRINT(AST_ObjectSymbol, function(self, output){
+        var def = self.symbol.definition();
+        if (def && def.mangled_name) {
+            output.print(self.symbol.name);
+            output.print(':');
+            output.space();
+            output.print(def.mangled_name);
+        } else {
+            output.print(self.symbol.name);
+        }
+    });
     DEFPRINT(AST_Undefined, function(self, output){
         output.print("void 0");
     });

lib/parse.js

@@ -1410,9 +1410,6 @@ function parse($TEXT, options) {
                 
                 if (!is("punc", ":")) {
                     // It's one of those object destructurings, the value is its own name
-                    if (!S.in_parameters) {
-                        croak("Invalid syntax", S.token.line, S.token.col);
-                    }
                     a.push(new AST_ObjectSymbol({
                         start: start,
                         end: start,

test/compress/destructuring.js

@@ -32,3 +32,12 @@ destructuring_vardef_in_loops: {
     }
     expect_exact: "for(var[x,y]in pairs);for(var[a]=0;;);for(var{c}of cees);"
 }
+destructuring_expressions: {
+    input: {
+        ({a, b});
+        [{a}];
+        f({x});
+    }
+    expect_exact: "({a,b});[{a}];f({x});"
+}
+