"Inject" something into a function's scope (NOT context) This is just a proof-of-concept. Because it uses eval() on every execution you get a 99% performance hit.

gistfile1.js

Function.prototype.compel = function(scope, args, scope_args) {
	
	var code = '';
	
	// Every scope_args entry will be added to this code
	for (var name in scope_args) {
		code += 'var ' + name + ' = scope_args["' + name + '"];';
	}
	
	// eval the code, so these variables are available in this scope
	eval(code);
	
	if (!this.__source__) this.__source__ = String(this);
	
	eval('var fnc = ' + this.__source__);

	// Apply the function source
	fnc.apply(scope, args);
}

// This should also be accessible
var a = 'a';

// The dummy function we'll "compel" later
var dummy = function() {
	
	// Print out var 'a', from the scope above
	console.log('Dummy a: ' + a);
	
	// Print out 'b', from the 'compelled' scope
	console.log('Dummy b: ' + b);
}


(function() {
	
	dummy.compel(this, [], {b: 'test-one'});
	dummy.compel(this, [], {b: 'test-two'});
	dummy.compel(this, [], {b: 'test-three'});
})();