Tutorials covering programming languages, type systems, architecture, tooling, and the patterns used to build software that lasts. Each chapter is standalone, built around real examples and verified facts.
A subquery that references a column from the outer query is correlated. This single characteristic changes everything about how the subquery behaves. An uncorrelated subquery runs once and produces a result that the outer query uses. A correlated subquery runs once for every row the outer query processes, because its result depends on the specific…
The @plugin directive is Tailwind v4’s mechanism for loading JavaScript-based plugins in a CSS-first configuration. In v3, plugins were registered in the plugins array of tailwind.config.js. In v4, the configuration moves to CSS, and the @plugin directive is the replacement. It loads a plugin from a package name or a local path, and it can…
TypeScript does not have higher-kinded types. This is a fact, not a limitation of your understanding. Higher-kinded types — the ability to abstract over a type constructor itself, as in F<T> where F is a parameter — are present in Haskell, Scala, and Rust (via traits and associated types), but they were never added to…
A <Teleport> normally resolves its target the moment it mounts. If the target element does not exist yet, Vue logs a warning and renders nothing. This is a common problem when the target is rendered by the same component tree: a modal might teleport to a container that appears later in the template, or a…
State management in Angular has moved through several generations. The first was services holding plain properties, mutated by components. The second was services holding BehaviorSubjects, with components subscribing to the observable streams. The third, in modern Angular, is signals — synchronous, dependency-tracking reactive values. But RxJS has not gone away: signals handle synchronous state, while…
The matrix() and matrix3d() functions are the most powerful — and most complex — transform functions in CSS. They let you apply exact mathematical transformations using matrices. Overview Function Dimensions Matrix Size Values matrix() 2D 3×3 (6 values) a, b, c, d, e, f matrix3d() 3D 4×4 (16 values) a through p 1. matrix() —…
A Dart application that talks to a REST API has two options. The first is the dart:io library, which provides the HttpClient class and works on the Dart VM, the server, the command-line tools, and the mobile applications. The HttpClient is the low-level, the full-featured client: it handles the persistent connections, the cookies, the authentication,…
Every container writes to stdout and stderr. That much is universal. What happens next depends entirely on the logging driver. The driver decides where the output goes, how it is formatted, and how long it is kept. Docker ships with a set of built-in drivers that cover the common cases: the local JSON files, the…
The Object global is a toolbox — it’s the constructor for objects, but it also holds static methods that work on any object. These methods are how you enumerate, copy, freeze, compare, and inspect objects. They’re the foundation of modern JavaScript patterns like immutability and destructuring. Key point: Most Object.* methods work on own enumerable…
Drizzle ORM is a TypeScript ORM built on a different philosophy than the traditional data frameworks. It does not try to abstract SQL away. It embraces SQL and provides a thin, type-safe layer on top of it. The schema is defined in TypeScript, the queries look like SQL, and the generated SQL is exactly what…