Create local short named aliases to global references

[Frederico Caldeira Knabben]

The packager should be able to scan a function for all global references made inside of it. A global reference is a name not declared inside the function scope with the "var" or "function" statements.

For example, suppose we have the following function:

function( param )
{
    if ( CKEDITOR.env.IE || CKEDITOR.tools.trim( param ) == '' )
        CKEDITOR.doStuff();

    CKEDITOR.doOtherStuff();

    if ( CKEDITOR.env.IE )
        alert( CKEDITOR );
   
    return CKEDITOR.tools.trim( CKEDITOR.doAgain() );
}

... it would end up like this:

function( A )
{
    var B = CKEDITOR;
    var C = B.env.IE,
        D = B.tools.trim;

    if ( C || D( A ) == '' )
        B.doStuff();

    B.doOtherStuff();

    if ( C )
        alert( B );
   
    return D( B.doAgain() );
}

Note that the code is smart enough to reuse the new names when creating other var names too.

[Frederico Caldeira Knabben]

Ok... my original example of changing CKEDITOR.tools.trim to "D" is wrong (as it looses the object scope), but the idea is still valid.

[Frederico Caldeira Knabben]

Milestone CKEditor 3.x deleted

[Piotrek Koszuliński]

Since we use a 3rd party code minifier there's no place for such improvements any more. We have to rely on the library we use.

Moreover, I did a test once and replaced most of longer tokens in the minified code with their short aliases. It allowed me to save <3% in minified code and <1% in gzipped. And in real life results would be worse, e.g. because of contexts preserving.