Preslav Rachev preslavrachev

Goal

The goal of this experiment is to try and implement the minimum requirements for the existence of a generic-style Option type in Go, similar to what we know from other languages, such as Java or Rust.

Motivation

Provide a fluent approach to error handling in Go which focuses on highlighting the "happy path", while being 100% idiomatic with Go's error handling convention.

NOTE: The core type is an interface called Option, having a single requirement:

This is a simple grayscale filter implementening image.Image. It can be used in place where an image.Image is expected.

img, err := loadImage("input.jpg")
// check error

err := saveImage(&GrayscaleFilter{img})
//check error

Daily Idea: Use CNNs to Categorize Apps, Based on Their App Store Screenshots

The idea is rather simple and feasible, but as of this moment, not really useful. It just popped up in my mind, and I decided to write it down in case someone is looking for a ML challenge to work on. The idea is very simple:

Use the iTunes Search API to download app screenshots and categorize them by folders, corresponding to the names of categories that those apps have been featured in.
Teach a simple convolutional neural network (CNN) to categorize apps based on screenshots provided
Try and evaluate the NNs capabilities using screenshots that are not present in the model.

Kotlin Basics: Create Executable Kotlin JARs, using Gradle

Kotlin is great for creating small command-line utilities, which can be packaged and distributed as normal JAR files. This short tutorial will show you how to:

Set up a Gradle project that supports Kotlin
Add a starting function
Configure your build to call this function when you execute your JAR.

Setting up Kotlin dependencies

Hamcrest Cheatsheet

Collection Matchers

Check if a collection contains a single item

assertThat(collection, hasItem("item1"));
assertThat(collection, not(hasItem("item2")));

	#!/usr/bin/env python3

	# <xbar.title>Claude Token Usage</xbar.title>
	# <xbar.version>v1.0</xbar.version>
	# <xbar.author>Preslav Rachev</xbar.author>
	# <xbar.desc>Shows today's Claude Code token usage in the Mac toolbar</xbar.desc>

	import json
	import subprocess
	import os

	package do

	type Void struct{}

	type Result[T any] interface {
	Unwrap() (T, error)
	}

	type defaultResult[T any] struct {
	val T

	def time_until_reset() do
	today = :erlang.date()
	now = :erlang.time()
	now_in_sec = :calendar.datetime_to_gregorian_seconds({today, now})
	days_until_next_monday = 8 - :calendar.day_of_the_week(today)

	midnight = {0, 0, 0}

	next_monday_in_sec =
	:calendar.datetime_to_gregorian_seconds(

	// src/index.ts

	import React, { Component } from 'react';
	import {
	StyleSheet,
	Text,
	View,
	ViewStyle,
	TextStyle
	} from 'react-native';

	public class DateUtil {

	public static Date asDate(LocalDate localDate) {
	return Date.from(localDate.atStartOfDay().atZone(ZoneId.systemDefault()).toInstant());
	}

	public static Date asDate(LocalDateTime localDateTime) {
	return Date.from(localDateTime.atZone(ZoneId.systemDefault()).toInstant());
	}