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
Go
UUID Generation (google/uuid)
`github.com/google/uuid` is the standard UUID library. v4 (random) for IDs, v7 (time-ordered) when you want UUIDs that sort chronologically and play nicely with B-tree indexes.
@admin
TypeScript
Shuffle (Fisher-Yates)
Uniformly shuffle an array in place using the modern Fisher-Yates algorithm. Returns the same array for chaining. Use crypto.getRandomValues for cryptographic uses.
Go
base64 Encode / Decode
`encoding/base64` has Standard, URL-safe, and Raw (no padding) variants. URL-safe replaces `+/` with `-_` so the output is safe in query strings and filenames.
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
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.
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.
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.
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).
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.
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.
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.