<h1 id="invariant">Invariant<a aria-hidden="true" class="anchor-heading icon-link" href="#invariant"></a></h1>
<ul>
<li>description: a set of assertions that must always hold true during the life of an object for the program to be valid.</li>
<li>eg An example of invariant could be that exactly one of two member variables should be null. Or that if one has a given value, then the set of allowed values for the other is this or that...</li>
<li><a title="Private" href="https://wiki.dendron.so/notes/hfyvYGJZQiUwQaaxQO27q.html" target="_blank" class="private">c.pattern (Private)</a> I sometime use a member function of the object to check that the invariant holds. If this is not the case, an assert is raised. And the method is called at the start and exit of each method that changes the object (in C++, this is only one line...)</li>
</ul>
<h2 id="resources">Resources<a aria-hidden="true" class="anchor-heading icon-link" href="#resources"></a></h2>
<ul>
<li><a href="https://softwareengineering.stackexchange.com/questions/32727/what-are-invariants-how-can-they-be-used-and-have-you-ever-used-it-in-your-pro">https://softwareengineering.stackexchange.com/questions/32727/what-are-invariants-how-can-they-be-used-and-have-you-ever-used-it-in-your-pro</a></li>
</ul>

Invariant

public-notes


Welcome! And beware!  

## Purpose

This vault is the "[[learning-in-public|ar.swyx.learn-in-public]]" part of my Second Brain. If you share some of my interests, please [reach out](https://djradon.github.io)! 

## Contents

- [[t]] my personal wikipedia
- [[idea]] (not necessarily mine)
- Resource Notes, including highlights, thoughts and metadata, for various things:
  - [[ar]] mostly articles, papers and web pages
  - [[book]]
  - [[community]]
  - [[course]]
  - [[event]]
  - [[game]]
  - [[loc]]
  - [[org]]
  - [[user]] 
  - [[prdct]] mostly software products, but also ontologies
  - [[recipe]]
  - [[video]] movies, tv episodes, youtube, etc
- [[vs]]
- [[wanted]]
- Some "Metadata Notes":
  - [[tags]] which may refer to any and multiple (or none) of the above
  - [[c]]: ways to categorize resources
  - [[p]]: ways to assert things about resources (mostly abandoned)

In terms of the [[t.km.zettelkasten]] method, this wiki is a commingling of literature notes with something @Sönke-Ahrens warned about: a "personal Wikipedia or a database" [^1]. 

In terms of [[t.tm.getting-things-done]], it's references, someday-maybe, next actions, and public projects.

## Beware!

This is a cluttered cupboard of jumbled jottings riddled with inaccuracies, confusion, and mistakes.

## What This Is Not

- evergreen-notes/digital-garden: for "synthesized" / original-ish publishable big-idea notes that should evolve over time, props to @andy-matuschak and @maggie-appleton
- blog: for "point-in-time" items to be shared: personal news, articles, etc.
  - e.g., [[ar.substack.carpe-noctem]]


[^1]: [[book.how-to-take-smart-notes]]  