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
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.
@admin
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.
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`).
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.
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.
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.
Kotlin
Write to a File
`writeText` overwrites; `appendText` appends. For multiple writes, use `bufferedWriter().use { }` for efficiency + auto-close.
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).
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.
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.
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.
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.
Kotlin
Ktor Server — Middleware (Plugins)
Plugins wrap every request — logging, CORS, auth, rate limiting. Install with `install(Plugin) { config }` at the application level.
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.
Java
Jackson — Basic ObjectMapper
`com.fasterxml.jackson.databind.ObjectMapper` is the JSON standard for Java. Construct once (it's expensive + thread-safe) and reuse for every serialization in your app.
Rust
Threads with thread::spawn + join
Native OS threads with `std::thread::spawn`. The returned `JoinHandle` lets you wait for the thread and get its return value. Use `move` to transfer ownership of captured variables.
PHP
Validate URL (scheme + host)
Beyond filter_var, also require the URL to have an http(s) scheme and a non-empty host. Rejects "javascript:" and other risky pseudo-schemes commonly seen in stored XSS.