Tags
#php
#kotlin
#bash
#go
#sql
#rust
#typescript
#html
#java
#python
#files
#utils
#strings
#http
#concurrency
#async
#json
#arrays
#security
#types
#crypto
#database
#dates
#format
HTML
Datalist — Autocomplete Suggestions
`<datalist>` attaches type-ahead suggestions to any text input. The user can still type something custom — it's suggestions, not a hard constraint.
@admin
HTML
Registration Form (new-password + email-verify)
`autocomplete="new-password"` tells password managers to OFFER a generated password instead of filling an existing one. `autocomplete="email"` and `inputmode="email"` give phones the right keyboard.
HTML
Email-Friendly Mailto + Tel Links
`mailto:` and `tel:` URI schemes open the user's email client or phone dialer directly. Support subject, body, cc, bcc as query params — and pre-format phone numbers for international.
HTML
Login Form (with autocomplete hints)
A complete login form with the autocomplete attributes that browsers + password managers depend on. Missing these causes 1Password, Bitwarden, and Chrome to mis-detect the form.
Java
ConcurrentHashMap — Thread-Safe Map
The default thread-safe map. Better than `Collections.synchronizedMap` — segmented locking allows multiple readers AND writers. Use `compute`, `merge`, `putIfAbsent` for atomic compound updates.
HTML
404 Not Found Page
A useful 404 isn't apologetic — it helps the user find what they were looking for. Include a search box, links back to popular pages, and a clear "Go home" CTA.
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.
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.
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.
Kotlin
associate and associateBy
`associateBy` builds a `Map<K, T>` keyed by a derived value. `associateWith` keys by the items themselves with derived values. `associate` lets you build both key and value from each item.
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).
Go
text/template — Simple Templating
Stdlib templating with `{{.Field}}` placeholders, range loops, if/else, and function pipelines. Safe alternative for non-HTML text (e.g. emails, config files).
TypeScript
User-Defined Type Guards
When TypeScript can't narrow a union for you, write a `x is T` predicate. Inside any block where the guard returns true, the compiler knows the narrower type.
Go
SHA-256 Hash of File or String
`crypto/sha256` is the canonical hash. Use the streaming `Hash` interface for files — never load multi-GB content into memory just to hash it.
Bash
Hash File (SHA-256)
Compute and verify file checksums for downloads, backups, and integrity audits. sha256sum on Linux; shasum -a 256 on macOS.
Java
CountDownLatch — Wait for N Events
Block one or more threads until a count of events occurs. Set the count up front; each event calls `countDown()`; waiters call `await()`. Classic "wait until all workers are ready" pattern.
Bash
Get Script's Own Directory
The "where am I" boilerplate that every nontrivial bash script needs. Resolves symlinks correctly with realpath, falls back gracefully if realpath is missing.