mistersourcerer/_.js

## _.js
Array.prototype.map = function(f) {
  return this.fold([], function(current, el) {
    return [f(current)].concat(el);
  });
}

Number.prototype.sum = function(val) {
  return this + val;
}

/*
Paulo Silveira @paulo_caelum
@sr_valeriano @guilhermecaelum
fold(array, op, init) { if(array.length == 0) return init;
return op(array[0], fold(array[...], op, init); }
*/

Array.prototype.fold = function(init, f) {
  if (this.length == 0) {
    return init;
  }

  return f(this[0], this.slice(1).fold(init, f));
}

console.log("::::")
a = ["1", "2", "3"];
r = a.map(function(a) {
 return a.concat(":");
});
console.log(r);

console.log("::::")
a = [1, 2, 3];
r = a.fold(1, function(a, b) {
  return a + b;
})
console.log(r);


Array.prototype.inject = Array.prototype.fold;

// any browser:
console.log("any browser:");
var fruits = ["banana", "orange", "lemon"];
var result = fruits.fold("*", function(i, v) {
  return i.concat(v);
});
console.log(result);

var numbers = [1, 2, 3];
result = numbers.fold(10, function(i, v) {
  return i + v;
});
console.log(result);
console.log("__________");


// only ffox:
console.log("just firefox:");
var _ = {};
_.__noSuchMethod__ = function(method, args) {
  var hasLazyArgument = args[0] == _;

  return (function(target){
    if (hasLazyArgument) {
      args = Array.prototype.slice.call(arguments);
      target = args.shift();
    }

    if (target[method]) {
      return target[method].apply(target, args);
    } else {
      console.log(target + "." + method + "()");
      target[method]();
    }
  });
}

var fruits = ["banana", "orange", "lemon"];

var result = fruits.fold("***", _.concat(_));
console.log(result);

result = fruits.map(_.concat(":::"));
console.log(result);

result = fruits.inject("***", _.concat(_));
console.log(result);

## underscore.html
<!DOCTYPE html>
<html>
<head><title>go</title></head>
<body>
<script src="_.js"></script>
</html>
	Array.prototype.map = function(f) {
	return this.fold([], function(current, el) {
	return [f(current)].concat(el);
	});
	}

	Number.prototype.sum = function(val) {
	return this + val;
	}

	/*
	Paulo Silveira @paulo_caelum
	@sr_valeriano @guilhermecaelum
	fold(array, op, init) { if(array.length == 0) return init;
	return op(array[0], fold(array[...], op, init); }
	*/

	Array.prototype.fold = function(init, f) {
	if (this.length == 0) {
	return init;
	}

	return f(this[0], this.slice(1).fold(init, f));
	}

	console.log("::::")
	a = ["1", "2", "3"];
	r = a.map(function(a) {
	return a.concat(":");
	});
	console.log(r);

	console.log("::::")
	a = [1, 2, 3];
	r = a.fold(1, function(a, b) {
	return a + b;
	})
	console.log(r);


	Array.prototype.inject = Array.prototype.fold;

	// any browser:
	console.log("any browser:");
	var fruits = ["banana", "orange", "lemon"];
	var result = fruits.fold("*", function(i, v) {
	return i.concat(v);
	});
	console.log(result);

	var numbers = [1, 2, 3];
	result = numbers.fold(10, function(i, v) {
	return i + v;
	});
	console.log(result);
	console.log("__________");


	// only ffox:
	console.log("just firefox:");
	var _ = {};
	_.__noSuchMethod__ = function(method, args) {
	var hasLazyArgument = args[0] == _;

	return (function(target){
	if (hasLazyArgument) {
	args = Array.prototype.slice.call(arguments);
	target = args.shift();
	}

	if (target[method]) {
	return target[method].apply(target, args);
	} else {
	console.log(target + "." + method + "()");
	target[method]();
	}
	});
	}

	var fruits = ["banana", "orange", "lemon"];

	var result = fruits.fold("***", _.concat(_));
	console.log(result);

	result = fruits.map(_.concat(":::"));
	console.log(result);

	result = fruits.inject("***", _.concat(_));
	console.log(result);
	<!DOCTYPE html>
	<html>
	<head><title>go</title></head>
	<body>
	<script src="_.js"></script>
	</html>