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.
React components often accumulate logic that has nothing to do with rendering. A component that fetches data, subscribes to a browser event, and manages a form field is doing three jobs at once. The rendering logic — the JSX — is buried under layers of state declarations and effect callbacks. Custom Hooks exist to pull…
Rust’s Result type is explicit about failure, but the standard library does not answer a harder question: what should the error type be? In a small function, a String or a custom enum works. In a real application, errors come from many sources — I/O, parsing, network, database, validation — and they need to propagate…
The RIGHT JOIN is the mirror image of the LEFT JOIN. It returns all rows from the right table and the matching rows from the left table. When a right row has no match in the left table, the left table’s columns are filled with NULL, and the row still appears in the result. The…
Every Tailwind utility you have written so far applies at every screen size. A flex class makes an element a flex container on a phone, a tablet, and a widescreen monitor. A text-lg class sets the font size to 1.125rem regardless of how much horizontal space is available. This is fine for simple layouts, but…
The previous two chapters covered utilities for objects (Partial, Pick, Omit, Record) and unions (Exclude, Extract, NonNullable). This chapter covers the utilities that work with functions and constructors: ReturnType<T> extracts a function’s return type, Parameters<T> extracts its parameter tuple, Awaited<T> unwraps a promise (recursively), and InstanceType<T> extracts the instance type from a constructor. All four…
A regular slot passes content in one direction. The parent provides the markup, the child places it, and the child has no say in what the content contains. But sometimes the child needs to share data with the content it renders. A list component knows the item and the index, and it wants the parent…
Errors are not exceptional. They are a normal part of every application that talks to a network, parses user input, or depends on code it does not control. A robust Angular application treats error handling as a design concern, not an afterthought. Errors appear at four distinct levels: within a component’s synchronous logic, within asynchronous…
These two media features help you create input-aware and accessibility-friendly interfaces — one detects hover capability, the other detects inverted color schemes. Overview of Features Feature Description Values hover Detects if the primary pointing device can hover none, hover inverted-colors Detects if the system uses inverted colors none, inverted 1. hover The hover media feature…
A Future on its own does nothing. It is a placeholder — a value that will exist later, an error that may occur later. The future does not act. It waits for the operation it represents to complete, and when that happens, it holds the result. To use that result, you attach callbacks. The three…
A container that exits is not always a container that should stay exited. A web server that crashes because of a transient network error should come back. A database that is killed by the OOM killer should restart. A batch job that completes successfully should stay stopped. Docker’s restart policies are the mechanism that distinguishes…