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).

27m 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`.

27m 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.

27m 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.

27m 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.

27m 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.

27m 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.

27m ago 0

PHP

Average / Median / Mode

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

27m 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).

27m 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.

27m 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.

27m 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.

27m 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.

27m 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.

27m ago 0

Rust

flat_map and Iterator::flatten

`flat_map(f)` is `map(f).flatten()` — map each item to an iterator, then concatenate. Indispensable for working with nested structures.

27m ago 0

Go

Test Helpers with t.Helper()

When you extract a verification routine into a helper, call `t.Helper()` so failure messages point to the CALLER line — not the helper line. One line, much better diagnostics.

27m ago 0

Java

flatMap — Flatten Nested Streams

Map each element to a Stream, then concatenate all of them into one. Used everywhere from "all words from a list of sentences" to "all permissions from a list of roles".

27m ago 0

SQL

COALESCE / NULLIF — Null Handling

`COALESCE(a, b, c)` returns the first non-NULL value — perfect for fallbacks. `NULLIF(a, b)` returns NULL when a equals b — handy for "treat sentinel as null".

27m ago 0

PHP

Validate Password Strength

Score a password 0–4 (NIST-inspired, not the full zxcvbn algorithm). Encourages length over complexity; flags well-known weak patterns. Use as a UI hint, not a hard barrier.

27m ago 0

HTML

All Standard Input Types

HTML5 input types each have built-in validation, on-screen keyboards (mobile), and pickers. Use them — `<input type="number">` beats `<input type="text">` + JS validation every time.

27m ago 0

HTML

Card Pattern (article + link wrapper)

The standard content card — image, title, excerpt, meta. Make the WHOLE card clickable by wrapping the title link and using `::after` to extend the hit area to the full card.

27m ago 0

Kotlin

Sequences — Lazy Collections

A `List` materializes every intermediate `map`/`filter` result. A `Sequence` processes ONE element through the whole pipeline at a time — better for big inputs or short-circuiting (`first`, `take`).

27m ago 0

JavaScript

Flatten Nested Array

Recursively flattens an array of arbitrary nesting depth into a single flat array. Accepts an optional depth limit — pass Infinity to flatten completely. Uses the native Array.flat when the browser supports it, otherwise falls back to a recursive reduce.

27m ago 0

TypeScript

Sleep / Delay

The async/await-friendly version of `setTimeout`. The one-liner everyone re-invents — keep it in a util file. Optional AbortSignal lets you cancel mid-wait.

27m ago 0

TypeScript

range — Lazy Number Iterator

A generator-based numeric range: `[start, end)` with an optional step. Lazy so it doesn't allocate a huge array up front; consume with for…of or Array.from.

27m ago 0

Rust

tokio mpsc Channel

Async multi-producer / single-consumer channel. Producers `.send()`, the single receiver `.recv().await` items as they arrive. Bounded — the channel back-pressures producers when full.

27m ago 0

Kotlin

map / filter / reduce

The three classic functional combinators. Each takes a lambda and returns a new collection (or a single value for reduce). Chain freely — intermediate allocations only matter at very large scale (use `Sequence` then).

27m ago 0

Kotlin

Write to a File

`writeText` overwrites; `appendText` appends. For multiple writes, use `bufferedWriter().use { }` for efficiency + auto-close.

27m ago 0

HTML

Code Markup — pre, code, kbd, samp, var

HTML has five semantic elements for technical text: `<code>` (source code), `<pre>` (preserve whitespace), `<kbd>` (keyboard input), `<samp>` (sample output), `<var>` (math/program variable). Each has a different meaning to screen readers and search engines.

27m ago 0

Kotlin

Ktor Server — Middleware (Plugins)

Plugins wrap every request — logging, CORS, auth, rate limiting. Install with `install(Plugin) { config }` at the application level.

27m ago 0