Monads in JavaScript

Passing arguments to a given callback function within a particular scope can be generalized using a monad:

/* Unit function */
function Monad(value)
  {
  // Construct monad and set value to given argument or undefined
  this.value = value || undefined;
  }

/* Constructor function */
Monad.prototype.pass = function(value, cb, scope)
  {
  // return constructor result if no default value is passed
  if (/undefined/.test(this.value) )
    {
    return new this.constructor();
    }
  // return callback result for given value in given context if scope is passed
  if(scope)
    {
    /* Bind function */
    return cb.call(scope, value);
    }
  // return callback result for given value otherwise
  return cb(value);
  }

 /* Separate arguments from function, and function from global scope */
 var foo = new Monad(RegExp);
 var bar = foo.pass(2, Function("count","return ++count"), Math);

References

• On Monads
• Transparent Persistence
• Monad-Dyad
• Common Logic Controlled English
• The JSON Parser Monad - Parsing JSON the fun way (Part 3)
• Fortran 77 Semantic Analysis
• Practical Monads
• A Poor Man'