To paraphrase uncle Bob from the “Clean Code” lectures: It is impossible to prove mathematically that software works, it can only be tested that it is not broken yet.

Something to think about.

Example:

Reactjs component and calculations:

import React from 'react';

type props = {
    width: number,
    height: number,
    frame: { x: number, y: number, w: number, h: number },
    textureUrl: string,
    background?: string,
};

class TextureImageResizeComponent extends React.Component<props> {

    render() {
        let {
            width,
            height,
            background,
            frame,
            textureUrl,
        } = this.props;


        if (width === 0) {
            width = frame.w;
        }

        if (height === 0) {
            height = frame.h;
        }

        return (
            <div style={{
                width: width,
                height: height,
                position: 'relative',
                background: background,
            }}>
                <div style={{
                    backgroundImage: 'url(' + textureUrl + ')',
                    width: frame.w,
                    height: frame.h,
                    backgroundPosition: '-' + frame.x + 'px -' + frame.y + 'px',
                    backgroundRepeat: 'no-repeat',
                    display: 'inline-block',
                    transform: 'scale(' + (width / frame.w) + ', ' + (height / frame.h) + ')',
                    top: 0,
                    left: 0,
                    marginTop: ((height - frame.h) / 2),
                    marginLeft: ((width - frame.w) / 2),
                    position: 'absolute',
                }}>

                </div>
            </div>
        );
    }
}

export default TextureImageResizeComponent;

Using list() function to swap variables values without adding more variables.

$url = 'blog:5';
list($type, $id) = explode(':', $url);
// in case that the url is 5:block
if (!is_numeric($id)) {
    list($type, $id) = [$id, $type];
}

Example table:

CREATE TABLE a
  (`id` int, `value` decimal(5,2))
;
	
INSERT INTO a
  (`id`, `value`)
VALUES
  (1, 5),
  (2, 1.25),
  (3, 3.7),
  (4, 17.3)
;

Goal – getting the rows in which the sum of value is 9.5

SET @counter := 0;

SELECT
  a.*,
  IF(@counter <= 9.5, 1, 0) AS included,
  (@counter := @counter + a.value) AS valueSum

FROM a
HAVING included = 1

The result:

/**
 * @author Ivan Gospodinow
 * @site http://ivangospodinow.com/?p=471
 *  
 * @param {callback} onUpdate
 * @return {callback} onStop
 */
export function countSeconds(onUpdate) {
    const start = new Date();
    const interval = setInterval(() => {
        onUpdate(parseInt((new Date().getTime() - start.getTime()) / 1000));
    }, 1000);

    return () => {
        clearInterval(interval);
    };
}

 
Usage:

/**
let seconds = 0;
let stopCounter = countSeconds(function(counter) {
  seconds = counter;
});

setTimeout(stopCounter, 5 * 1000);
console.log(seconds);
// 2

“Big teams create big software slowly” by Kevlin Henney

Everybody dies and winter covers all of Westeros.

/**
 * Corvert array data to hidden inputs
 * to pass as form data
 *
 * Example: [data => [sub1 => 1, sub2 => 2]]
 * 
 * 
 *
 * @author Ivan Gospodinow
 * @see http://ivangospodinow.com/?p=455
 * @param array $array
 * @param [array | string] $exclude
 * @return string
 */
function arrayToHiddenInput(array $array, $exclude = null)
{
    $hiddens = [];
    $strParams = urldecode(http_build_query($array));

    if (!empty($strParams)) {
        $params = explode('&', $strParams);
        foreach ($params as $param) {
            list($name, $value) = explode('=', $param);

            if (is_array($exclude) && in_array($name, $exclude)) {
                continue;
            } else if ($name == $exclude) {
                continue;
            }

            $hiddens[] = sprintf(
                '',
                $name,
                $value
            );
        }
    }

    return implode(PHP_EOL, $hiddens);
}

Example:

echo arrayToHiddenInput(['data' => ['sub1' => 1, 'sub2' => 2]]);

Result:

Simple as that

Well, for 2 years online and zero working real live services, I have to call it – scam.

Code execution is limited to 15 seconds, which makes integration with 3rd party services not possible, thus falls most claims.

https://ethereum.stackexchange.com/questions/2598/is-code-execution-time-limited-by-the-block-time

Minutes after we watched “Murder on the Orient Express” we started to think how the author of the book came up with such a brilliant ideas, not just for that story but all of her novels. Her stories are always so complex, you can never guess what will happen in the end.

Agatha Christie is one of the greatest crime authors with 66 detective novels, 14 short stories and longest-running play – a murder mystery“The Mousetrap”.

So we started talking, and came up with the idea that she probably read curtain newspaper stories and then wrote the story behind the titles of them. Which is quite brilliant because she used only the headlines and then wrote the story. Most of the authors focus on the story and the end came as a result of it. We started to realize how different and genius is to have the end and to let the imagination cover the rest. She did something more, she put her most famous character in the center of most of the stories – the detective Hercule Poirot. She wrote him as world-renowned private detective, unsurpassed in his intelligence and understanding of the criminal mind. Famous as much for his moustaches as his little grey cells. He became her label at the same time with herunique type of writing. To write the story after you have only the headline of something completely different happen somewhere, is brilliant.

Or this is just our theory.

In the end, we enjoyed the movie, (I read all of her books during the years) and the discussion after it were inspiring and fun.

credits: Antoniya Dyakova Gospodinova