toMethod and toLambda - higher order helpers for codebases that use both functional and OOP styles

tomethod-toLambda.js

// Convert a function that does not use `this` context into a function that
// does. The category of information that was previously passed as the first
// parameter of the function is now its `this` context.
function toMethod(lambda) {
  return function () {
    var args = [this];
    var concat = args.concat;
    // Spread arguments over arity of concat, since arguments is not a true array.
    var combined = concat.apply(args, arguments);
    return lambda.apply(null, combined);
  };
}

// Convert a method func that uses a `this` context into a function that takes
// the context object as the first parameter.
function toLambda(method) {
  return function (context) {
    var args = Array.prototype.slice.call(arguments, 1);
    return method.apply(context, args);
  };
}

I like the use of the term "lambda" in your example to distinguish between methods and traditional functions. Maybe toLambda and toMethod are better names?

Update: changed the name to Lambda.