#ObjectScript

Advent of Code is a series of programming challenges for beginners and experienced Caché programmers.

For an introduction : look at article https://community.intersystems.com/post/advent-code-2016-day1-no-time-ta...

In this challenge, you need to find a password using instructions to move on a keypad.
Instructions can be U(p), D(own), L(eft) and R(ight).

You start at button 5 on a keypad like

Hello again and welcome to the next tutorial on this series: Part 4 - Sharing data across router methods. Here we are going to learn how to share a object containing data that is available for read across every router methods.

You're required to complete at least the Part 1 before entering this one. Still, this is supposed to be a really short tutorial, since there isn't much to be said about data sharing.

It is with great pleasure that the CIUSSS de l'Estrie - CHUS is sharing the mocking framework it developed and presented at the InterSystems Summit 2017. I will update this post with more detailed instructions in the next few weeks but I wanted to share the code and presentation quickly :

https://gitlab.com/ciussse-drit-srd-public/Mocking-Framework

The DeclarativeCOS project is a heartfelt cry about programming in the COS language.

The purpose of the project is to draw attention of the public to improving the inner core of COS.

The idea of the project is the support of a laconic syntax for cycles and collections.

So what is this laconic something that I have come up with? Welcome to the examples below!

Examples

The key concept underlying the project is the declarative approach to writing code. You need to specify WHAT should be used and HOW.

In a previous exercise, I was able to show the power of Caché.
A medium-designed set of interdependent tables with some GB of data.
URLs cross reference over some million pages resulting in ~3 billion records

Competition was between

• Caché
• PostgreSQL
• MySQL

Criteria were Speed + Storage consumption
I composed a customized loader fed over a "raw" TCP connection
Mapping the "objects" into the final table by directly writing to Global Storage.,

I needed to pass through a file with Ensemble but the operation wasn't writing some filenames as given because the EnsLib.File.PassthroughOperation 'sanitizes' filenames removing characters that are not valid on some operating
systems;
09000655_AEDC_C3344059_A/E_Martin Browne_09000655_201706221018.pdf
09000655_AEDC_C3344059_A#47E_Martin_Browne_09000655_201706221018.pdf

This is a translation of the following article. Thanks [@Evgeny Shvarov] for the help in translation.

This post is also available on Habrahabr^ru.

The post was inspired by this Habrahabr article: Interval-associative array^ru→en.

Since the original implementation relies on Python slices, the Caché public may find the following article useful: Everything you wanted to know about slices^ru→en.

Note: Please note that the exact functional equivalent of Python slices has never been implemented in Caché, since this functionality has never been required.

And, of course, some theory: Interval tree^ru→en.

All right, let’s cut to the chase and take a look at some examples.

EDIT: This article has been updated with up-to-date information about the Port project, which now includes a tutorial for basic usage.

The Port project is something that I've introduced more than two years ago but I hadn't enough room to elaborate a tutorial on how to use it till now.

First, the motivation:

Hi Community,

This post is to introduce one of my first project in COS, I created when started to learn the language and until today I'm keeping improve it.

The CosFaker(here on Github) is a pure COS library for generating fake data.

cosFaker vs Populate Utils

So why use cosFaker if caché has the populate data utility?

Say you have a global in one database that you instead want to map from a different database. If you just create a global mapping to the new database, the existing global will become inaccessible because it still lives on the old database. The documentation notes this problem here but doesn't give details on how to fix it.

Introduction

The common requirement in many applications is logging of data changes in a database - which data has changed, who changed them and when (audit logging). There are many articles about this question and there are different approaches on how to do that in Caché.

On the back of my recent post on writing bug-less code I wanted to raise a few suggestions (to ISC) that would help prevent certain types of bugs at compile time. I've probably missed a few, but these are the main ones in my mind. Please contribute more suggestions.

Btw, these also serve as potential gotchas for new COS developers.

Inspired by the article "Declarative development in Caché" that's still trending on the dev com. The OP explored a functional style of iterating over a collection. A comment today suggested "Caché would need syntax support for anonymous functions".

With Macros you can kind of get anonymous like syntax using dot notation.

This is not production code, but it does work. First the macros...

Have you ever thought what could be a reason why some development environment (database, language) would eventually become popular? What part of this popularity could be explain as language quality? What by new and idioms approaches introduced by early language adopters? What is due to healthy ecosystem collaboration? What is due to some marketing genius?