Emit literal content with Less plugin functions and detached rulesets

literal.js

function Literal( text ) {
  this.text = text;
}

Literal.prototype = new tree.Node();
Literal.prototype.constructor = Literal;
Literal.prototype.type = "Literal";
Literal.prototype.accept = function ( visitor ) {};
Literal.prototype.eval = function ( context ) {
  return new Literal( this.text );
};
Literal.prototype.genCSS = function ( context, output ) {
  output.add( this.text );
};

functions.add( "literal", function( text ) {
  var literal, ruleset;
  
  literal = new Literal( String( text.value ));
  ruleset = new tree.Ruleset( null, [ literal ]);
    
  return new tree.DetachedRuleset( ruleset, []);
});

literal.less

.link {
  @plugin "literal.js";
  @literal : literal( "@define-placeholder item-link {};" );
  @literal();
}