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
net/url — Build Query Strings Safely
Stop concatenating `?a=1&b=2` by hand. `url.Values` (a `map[string][]string`) escapes correctly, handles repeated keys, and `url.URL.String()` renders the canonical form.
@admin
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.
Rust
Async/Await with tokio
`async fn` returns a future; `.await` drives it. tokio is the de-facto runtime. The `#[tokio::main]` attribute turns `main` into the runtime entry point.
PHP
Validate UUID (any version)
Match the canonical 8-4-4-4-12 hex format, optionally pinning to a specific UUID version (1-5). Case-insensitive.
Bash
DNS Lookup (dig / host / getent)
Three options depending on what's installed: dig is most flexible, host is concise, getent uses the system's resolver and respects /etc/hosts.
PHP
Atomic Counter with flock
A single-file counter that survives concurrent increments correctly using flock + read-modify-write inside the locked region. Useful for crude visitor or job-id counters when you don't want a DB.
PHP
Find Open TCP Port
Probe whether a remote host:port accepts connections, with a configurable timeout. Useful for quick health checks in deploy scripts.
Kotlin
Sealed Classes — Closed Type Hierarchies
`sealed` restricts subclassing to the same module. Combined with exhaustive `when`, the compiler enforces handling of every variant — refactor-friendly state machines.
Go
Generic Function with Type Parameters
Go 1.18+ generics. `[T any]` is unconstrained; `[T comparable]` allows == and !=; custom constraints work too. The compiler infers T from arguments.
PHP
Rotating Log Writer
Append to a single log file but auto-rotate to .1/.2/.3 once the file exceeds a configurable size. No external dependencies — just rename + size check.
Java
Records — Concise Data Classes (Java 16+)
`record` generates a constructor, accessors, `equals`, `hashCode`, and `toString` from a one-line declaration. Replaces 50 lines of POJO boilerplate. Records are implicitly final and immutable.
Rust
Clone vs Copy — When to Use Each
Stack-allocated primitives implement `Copy` (auto-duplicated). Heap-owning types like `String` and `Vec` only implement `Clone` (you must explicitly call `.clone()` to opt into the deep copy cost).
Python
Deprecation Warning Decorator
Mark a function as deprecated so callers get a DeprecationWarning the first time it's called. Includes the replacement function name in the message so callers know what to switch to.
PHP
Levenshtein Similarity Percentage
Wrap PHP's built-in levenshtein() to return a similarity score from 0.0 (totally different) to 1.0 (identical). Handy for "did you mean…?" suggestions.
Go
flag — Stdlib CLI Parser
The `flag` package is the minimal-dep CLI parser shipped with Go. Sufficient for many tools; reach for `spf13/cobra` or `urfave/cli` for subcommands and richer UX.
JavaScript
Long Polling Helper
Implements a long-polling loop that repeatedly calls a fetch endpoint and invokes a callback with the result. Backs off exponentially on errors and stops cleanly when cancelled via the returned stop function. A simple alternative to WebSockets for low-frequency server-push events without SSE support.
Go
JSON Marshal / Unmarshal
`encoding/json` is the standard library JSON parser. `Marshal` produces compact JSON; `MarshalIndent` produces pretty-printed. `Unmarshal` decodes into a typed value (struct, map, or any).