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
Java
Collectors.groupingBy — Group by Key
Like SQL GROUP BY for streams. Produces a `Map<K, List<V>>` (or any downstream collector you specify). Indispensable for analytics-style aggregations.
@admin
Go
Graceful HTTP Shutdown
On SIGINT/SIGTERM, stop accepting new connections but let in-flight requests finish. The `http.Server.Shutdown` method does exactly that — with a deadline.
Bash
Pretty-Print JSON from cURL
Pipe API responses through jq for syntax-colored, indented output. Also great for extracting specific fields without writing a parser.
TypeScript
Concurrency Limiter (semaphore)
Run an array of async tasks but limit concurrency to N at a time — like p-limit, in 30 lines. Preserves input order in the output array.
PHP
Format Money with Currency
Format an amount of cents as a localized currency string using NumberFormatter from intl. Falls back to a basic sprintf if intl isn't available.
PHP
Simple File-Backed Cache
A tiny key-value cache with TTL, persisted as a serialized PHP file per key. Good enough for memoizing expensive computations on a single machine; replace with Redis when scaling out.
PHP
UTF-8 Safe substr / strlen
Wrap mb_* with sensible defaults so you stop accidentally chopping multi-byte characters in half. Defensive helpers for projects where input is not guaranteed ASCII.
JavaScript
Validate Email Address
Validates an email address using a battle-tested regex that covers the vast majority of real-world addresses without being overly strict. For server-side code, pair this with a confirmation email step — client-side regex alone is not a security measure. Returns a boolean for easy conditional use.
JavaScript
Deep Clone Object
Creates a true deep copy of any serialisable object or array — nested objects, arrays, dates (as ISO strings). Uses structuredClone when available (modern browsers/Node 17+) and falls back to JSON round-trip for older environments. Does not handle functions, undefined, or circular references.
Kotlin
kotlinx.serialization — JSON Basics
Compile-time code generation for JSON serialization. Annotate `@Serializable` on a data class; `Json.encodeToString` and `Json.decodeFromString` are typed.
SQL
WITH Clause — Common Table Expressions
Name a subquery so you can refer to it like a table. Improves readability for complex multi-stage queries — and lets you reuse the same logical block multiple times.
Go
Crypto-Random Bytes + Hex/Base64
`crypto/rand` is the cryptographic CSPRNG. Use it for tokens, session IDs, API keys, password salts — anywhere `math/rand` would be a security bug.
Rust
tracing — Structured Logging Setup
`tracing` is the structured-logging story for async Rust — better than `log` for anything tokio-based. Drop in this initializer and use `info!`, `warn!`, `error!` macros throughout.
Python
ThreadPoolExecutor for I/O-Bound Work
Parallelize I/O-bound tasks (HTTP requests, file reads, DB queries) without writing thread management code. The default thread count is min(32, os.cpu_count() + 4) — usually the right call.
Python
Word-Safe Truncate
Cap a string at `max_len` chars without splitting a word; append an ellipsis when truncated. Backs off to the last space if cutting mid-word would happen.
TypeScript
Format Duration in ms
Render a number of milliseconds as a human-friendly duration: "1h 23m 45s". Skips leading-zero units automatically so short durations are concise.
PHP
Safe JSON Decode (no exceptions)
Wrap json_decode so invalid input gives you a clear false rather than a silent null. PHP 7.3+ JSON_THROW_ON_ERROR makes this cleaner — but the wrapper preserves a simple bool API.