swap DOM nodes with HTML

annotated.js

function(
  a, // the node to be replaced
  b, // the node or HTML to replace it
  c, // placeholder
){
  a.parentNode                  // from the parent of the given node,
    .replaceChild( b.nodeType   // replace the original node with
      ? b                       // the replacement node, if it is a node,
      : (                       // or otherwise
        (                       // create it by
          ( c = document        // getting the document,
            .createElement("a") // creating any element,
          )
          .innerHTML =          // and writing its html
            b.replace(          // by replacing
              /^\s+/,           // any leading whitespace
              ""                // with nothing,
            )
        ),
        c.firstChild            // and then fetching its first child.
      ),
    a
  )
}

index.js

function(a,b,c){a.parentNode.replaceChild(b.nodeType?b:(((c=document.createElement("a")).innerHTML=b.replace(/^\s+/,"")),c.firstChild),a)}

LICENSE.txt

            DO WHAT THE FUCK YOU WANT TO PUBLIC LICENSE
                    Version 2, December 2004

 Copyright (C) 2011 Jed Schmidt <http://jed.is>

 Everyone is permitted to copy and distribute verbatim or modified
 copies of this license document, and changing it is allowed as long
 as the name is changed.

            DO WHAT THE FUCK YOU WANT TO PUBLIC LICENSE
   TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION

  0. You just DO WHAT THE FUCK YOU WANT TO.

package.json

{
  "name": "swap",
  "keywords": ["swap", "replace", "DOM", "HTML"]
}

@atk, regexps don't execute in IE.

f..., I forgot about IE! Sorry - but I found another way to shave off 2 bytes: instead of b.nodeType, you could test ""+b===b.