Rust

Fan-Out with try_join_all

Run N async operations concurrently and collect every Result. Fails fast on the first error; `join_all` is the variant that always waits for everyone.

46m ago 0

Rust

unsafe — When and How

Most Rust is safe. `unsafe` only lets you do 5 things the compiler can't check (raw pointer deref, mutable static, unsafe fn / trait, FFI, union access). Wrap unsafe operations in safe abstractions.

46m ago 0

Go

HTTP POST JSON Body

Build a request with `http.NewRequestWithContext`, set headers, send via your client. The context plumbing is what lets callers cancel mid-request.

46m ago 0

Go

Interface Segregation — Small Interfaces

"The bigger the interface, the weaker the abstraction." Go encourages small, focused interfaces (often just one method) — io.Reader, io.Writer, fmt.Stringer. Define them at the consumer side.

46m ago 0

Go

Build Tags + Conditional Compilation

`//go:build` constraints control which files compile under which conditions — different code for Linux vs Windows, dev vs prod, with/without a feature. Standard library uses this heavily.

46m ago 0

Java

Switch Expressions (Java 14+)

`switch` is now also an expression — it returns a value. Use `->` arrows for fall-through-free arms; `yield` inside `{ }` blocks for multi-statement arms. No more accidental forgotten `break`.

46m ago 0

Kotlin

minOf / maxOf / sumOf / averageOf

Numerical reducers with a selector lambda — much cleaner than `.map { ... }.max()` chains. `sumOf` is type-aware (returns Int, Long, Double, BigDecimal as appropriate).

46m ago 0

PHP

Simple cURL GET with Timeout

A no-dependency HTTP GET helper with sensible defaults: short timeout, follow redirects, return body as string, throw on transport error. Pass extra headers as a simple associative array.

46m ago 0

TypeScript

Capitalize / Title-Case

Two common case transforms. `capitalize` for the first letter only; `titleCase` for every word, with small "stop words" left lowercase except at the edges.

46m ago 0

JavaScript

Validate URL

Validates whether a string is a well-formed URL using the native URL constructor, which matches browser parsing behaviour exactly. Optionally restricts to specific protocols (defaults to http and https). No regex maintenance required — if the browser can parse it as a URL, this returns true.

46m ago 0

JavaScript

Retry Promise with Backoff

Retries a Promise-returning function up to a specified number of times with configurable exponential backoff and optional jitter. Accepts a shouldRetry predicate so you can skip retries on specific error types (e.g. 401 Unauthorized). Returns the resolved value or re-throws the last error after exhausting retries.

46m ago 0

JavaScript

Worker Pool (Web Workers)

Manages a pool of Web Workers for CPU-intensive tasks (image processing, crypto, parsing). Distributes tasks across available workers using a round-robin strategy and returns a Promise per task. Falls back gracefully to inline execution in environments where workers are unavailable.

46m ago 0

PHP

Validate Credit Card (Luhn check)

Apply the Luhn checksum algorithm to a credit card number. Strips spaces/dashes first. This validates the format — not whether the card actually exists or has funds.

46m ago 0

PHP

Validate Hex Color

Accept #RGB, #RGBA, #RRGGBB, or #RRGGBBAA hex colors (with or without the leading #). Returns the normalized 6/8-digit lowercase form.

46m ago 0

PHP

Singleton Trait

A reusable trait that turns any class into a lazily-instantiated singleton with a single ::instance() accessor. Throws on clone/wakeup to prevent accidental duplication.

46m ago 0

Python

Async Retry with Exponential Backoff

Retry an async operation up to N times, doubling the wait each attempt with random jitter to avoid thundering herd. Predicate controls retryability so 4xx errors stop immediately.

46m ago 0

Java

java.time — Instant, LocalDate, ZonedDateTime

Java 8's `java.time` package replaced the broken `Date`/`Calendar`. Three types you actually use: `Instant` (UTC moment), `LocalDate` (date with no tz), `ZonedDateTime` (date+time in a zone).

46m ago 0

Java

HttpClient — Async (CompletableFuture)

`sendAsync` returns a `CompletableFuture<HttpResponse<T>>` — chain it like any other CF. Fan out N requests, wait for all with `CompletableFuture.allOf`.

46m ago 0

JavaScript

Detect Mobile / Device Type

Detects whether the user is on a mobile, tablet, or desktop device. The navigator.userAgentData API (Chromium) is preferred for its structured data; falls back to a User-Agent regex for Safari and Firefox. Useful for conditional rendering, touch event handling, and analytics segmentation.

46m ago 0

Python

asyncio.to_thread — Run Blocking Code

Wrap a blocking function so it doesn't freeze the event loop. asyncio.to_thread (3.9+) schedules the call onto the default executor and awaits the result.

46m ago 0

Go

Minimal net/http Server

The standard library ships a production-quality HTTP server. `http.HandleFunc` registers a function; `http.ListenAndServe` blocks forever serving requests.

46m ago 0

HTML

Modern Meta Tags (viewport, theme-color, etc.)

The non-obvious meta tags that improve mobile rendering, status-bar coloring, and dark-mode behavior in 2025 browsers. Copy this block whole.

46m ago 0

Kotlin

windowed and chunked

`chunked(n)` splits a list into NON-overlapping pieces of size n. `windowed(n)` slides a fixed-size window across — overlapping. Useful for moving averages, n-grams, batch APIs.

46m ago 0

PHP

Average / Median / Mode

Three classic descriptive statistics over a numeric array. Built without any external math library — just sort + count.

46m ago 0

PHP

RGB ↔ Hex Conversion

Two-way conversion between #RRGGBB hex strings and [R, G, B] arrays. Handy when working with theme colors that come from both sources (CSS strings vs. RGB sliders).

46m ago 0

TypeScript

Debounce (typed)

Wait until the caller stops invoking for `delay` ms, then call the function with the most recent arguments. The TS version preserves the original signature so the returned function has the same parameters.

46m ago 0

Rust

axum — Hello World HTTP Server

axum is the tokio-team's web framework — composable, type-safe handlers built on tower middleware. The hello-world is small enough to read in one screen.

46m ago 0

Go

Pipeline (channel chain)

A pipeline is a chain of stages connected by channels — each stage runs in its own goroutine. Classic Go pattern for streaming transformations with backpressure built in.

46m ago 0

Java

java.time — Duration and Period

`Duration` for elapsed time (hours/minutes/seconds). `Period` for calendar amounts (days/months/years). Don't mix — calendar math respects month lengths and DST; clock math doesn't.

46m ago 0

PHP

CSRF Token Generate + Verify

Per-session CSRF token helpers using hash_equals for constant-time comparison. Token is regenerated on logout but persists across requests within a session.

46m ago 0