#ObjectScript

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

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

Today's challenge is about decompressing input that is compressed in an experimental format.
In the format, markers indicate how much time a number of characters need to be repeated.

For example :

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

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

The challenge of day 5 is to calculate a password of 8 characters by finding the MD5 hash of the input and an increasing integer index.
The password is constructed by taking the 6th character of the first 8 hashes that start with 5 zeroes (in hex representation).

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

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

The challenge of today has nothing to do with real two-factor authentication ! (sorry if you came to this article by searching the real thing)

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

For an introduction : goto to article https://community.intersystems.com/post/advent-code-2016-day1-no-time-ta... or look at the http://adventofcode.com/ website.

Advent of Code is a series of 25 small programming challenges, it's an ideal way for beginners to start learning a computer language, and for advanced people to sharpen their programming skills.

There are small and bigger puzzles, which you can solve typically in half an hour to a few hours. (Looking at the leaderboard, the top aces can do them in less than 10 minutes.)

Advent of Code is created by Eric Wastl, you can find all info on https://adventofcode.com/.

Hello again and welcome to the Part 3 - Using the SQL API!

If you have been wondering about how to use SQL along with Frontier, you came to the right place. That's because since Frontier wraps the common Caché SQL API within it's own, you need to use the API provided from it. But you don't need to worry about its learning curve, because the Frontier SQL API is really simple.

XDATA is used for a whole host of ISC libraries to store things like Zen pages, BPL logic and DTL transformations.

XDATA is the equivalent of XML config files of the JAVA world and JSON config files of the JavaScript / NPM world.

Whilst Atelier looks to shift source code to the disk, XDATA will remain a key component to source control our projects config / meta data.

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.,

Quotes (1NF/2NF/3NF)^ru:

Every row-and-column intersection contains exactly one value from the applicable domain (and nothing else).
The same value can be atomic or non-atomic depending on the purpose of this value. For example, “4286” can be

• atomic, if its denotes “a credit card’s PIN code” (if it’s broken down or reshuffled, it is of no use any longer)
• non-atomic, if it’s just a “sequence of numbers” (the value still makes sense if broken down into several parts or reshuffled)

This article explores the standard methods of increasing the performance of SQL queries involving the following types of fields: string, date, simple list (in the $LB format), "list of <...>" and "array of <...>".

Caché offers a number of methods for going through a collection and doing something with its elements. The easiest method uses a while-loop and lets you fulfill the task in an imperative manner. The developer needs to take care of the iterator, jumping to the next element and checking if the loop is within the collection.

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.

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

Let's assume that you wrote a program that shows "Hello World!", for example:

  write "Hello, World!"

The program works and everyone is happy.

With time, however, your program becomes more complex, gets more features and you eventually need to show the same string in different languages. Moreover you don't know the number and names of these languages.

The spoiler below contains a description of how the task of multi-language localization is solved 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...