State Monad in JavaScript

state-monad.js

var push = function (value) {
  return function (stack) {
    var newStack = [value].concat(stack);
    return { value:undefined, stack:newStack };
  };
};

var pop = function () {
  return function (stack) {
    var value = stack[0];
    var newStack = stack.slice(1);
    return { value:value, stack:newStack };
  };
};

var bind = function (stackOperation, continuation) {
  return function (stack) {
    var result = stackOperation(stack);
    return continuation(result.value)(result.stack);
  };
};

var result = function (value) {
  return function (stack) {
    return { value:value, stack:stack };
  };
};

var evalStack = function (stackComputation, initialStack) {
  var result = stackComputation(initialStack);
  return result.value;
};

var execStack = function (stackComputation, initialStack) {
  var result = stackComputation(initialStack);
  return result.stack;
};

var runStack = function (stackComputation, initialStack) {
  return stackComputation(initialStack);
};

var computation0 = bind(push(4), function () {
  return bind(push(5), function () {
    return bind(pop(), function (value0) {
      return bind(pop(), function (value1) {
        return result(value0 + ":" + value1);
      });
    });
  });
});

var computation1 = bind(
  push(2), function () { return bind(
  push(3), function () { return bind(
  pop(),   function (value0) { return bind(
  pop(),   function (value1) {
    return result(value0 + ":" + value1);
  });
});});});

var composedComputation = bind(computation0, function (value0) {
  return bind(computation1, function (value1) {
    return result(value0 + ":" + value1);    
  });
});

var initialStack = [];
var finalResult = runStack(composedComputation, initialStack);

console.log(finalResult);