gregoryyoung

{
	"Introduction" : {
		"Introduction" : "Introduction.md"
	},
	"blank_page": {
		"Introduction": "blank_page.md"
	},
	"Messages": {
		"Command": {
			"shortDescription": "A Command is a message stating to do something",

gregoryyoung

{
	"Introduction" : {
		"Introduction" : "Introduction.md"
	},
	"blank_page": {
		"Introduction": "blank_page.md"
	},
	"Messages": {
		"Command": {
			"shortDescription": "A Command is a message stating to do something",

gregoryyoung

Value objects are an important concept in DDD. This kata is made both to learn value objects and to learn better ways of testing.

Write a probability value object. It should contain the following methods:
   Probability CombinedWith(Probability)
   Probability InverseOf()
   Probability Either(Probability)

if you forget your probability math:
   Either:P(A) + P(B) - P(A)P(B)
   CombinedWith: P(A)P(B)

gregoryyoung

Greg's Stop Loss Kata

Testing is very hard when time is involved ...

A trailing stop loss is a term used in financial trading. For a very in depth explanation you can read here http://www.investopedia.com/articles/trading/03/080603.asp and http://en.wikipedia.org/wiki/Order_(exchange)#Stop_orders

However we do not need a huge amount of background in order to do the kata as we are going to limit the problem a bit.

The general idea is that when you buy into a stock at a price say $10. You want it to automatically get sold if the stock goes below $9 (-$1). If we use the term "trailing" that means that id the price goes up to $11 then the sell point becomes $10.

gregoryyoung

"Patterns" {
	"Event Logs" : {
		"Introduction" : "eventlog_intro.md",
		"Appending Event Log" : {
			"shortDescription" : "A simple appending Event Log",
			"longDescription" : "appendingfileeventlog.md",
			"image" : "patterns/appendingfileeventlog.png"
		},
		"Event Log" : {
			"shortDescription" : "An EventLog is a log containing a series of events.",

gregoryyoung

So packet arbitrage is a common feature with udp protocols *especially* multicast protocols.

What is being discussed is a mechnism of dealing with the "possibly lossy" behaviour of UDP. UDP can lose packets 
so we will have N sources sending identical packets (eg: they have the same sequence numbers/data/etc). 

Packet #133 on multicast A is identical to packet #133 on multicast B but they have disinct network paths.

In doing this when I receive packet #133 in the sequence I do not need to care **which** feed it came down, they are all the same. 

I accept the packet from the feed I find it **first** and in proper order. This leads to far less lossage (UDP right?) and 

gregoryyoung

Who came up with the concept of value objects and why are they used?
The concept of value objects originated in the field of object-oriented programming, and it is generally attributed to Eric Evans, who introduced the concept in his book "Domain-Driven Design: Tackling Complexity in the Heart of Software" published in 2003.

Value objects are used to represent immutable values or concepts in a domain model. They are objects that have no identity and are defined entirely by their attributes. In other words, two value objects with the same attributes are considered to be the same, regardless of their individual identities.

Value objects are useful because they provide a way to encapsulate complex data and behavior into a single object. They help to reduce the complexity of domain models by providing a way to represent complex concepts in a simple, self-contained manner. Additionally, value objects are often used to help enforce business rules and constraints, as they can be designed to only allow valid value

gregoryyoung

An event-sourced aggregate is a design pattern that allows you to build a system based on events, in which changes to the state of an aggregate are recorded as a series of events. Here's an example of what the code for an event-sourced aggregate might look like in Python:

python
Copy code
class Event:
    def __init__(self, data):
        self.data = data

class Aggregate:
    def __init__(self, events=None):

gregoryyoung

I used ... C:\>curl http://127.0.0.1:2113/stats

This is the output.

{
  "proc": {
    "startTime": "2022-12-28T17:26:46.4771160Z",
    "id": 21588,
    "mem": 88649728,
    "cpu": -1.0,

gregoryyoung

{
  "proc": {
    "startTime": "string",
    "id": 0,
    "mem": 0,
    "cpu": 0,
    "cpuScaled": 0,
    "threadsCount": 0,
    "contentionsRate": 0,
    "thrownExceptionsRate": 0,