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
log/slog — Structured Logging
`log/slog` (Go 1.21+) is the standard structured logger. Drop-in replacement for `log` with key/value attributes and JSON output for log-pipeline ingestion.
@admin
Rust
Builder Pattern with Method Chaining
Construct complex objects step-by-step with `self`-returning methods. Type-state can enforce required vs. optional fields at compile time — but the simple version is plenty for most cases.
Bash
Sum a Column with awk
Awk's default field splitter is whitespace; pass a single character with -F. Perfect for summing the Nth column of a log file or CSV.
PHP
Detect MIME Type via Magic Bytes
Use PHP's built-in finfo (libmagic) to detect a file's true MIME type from its bytes — not from the extension, which can be lied about. Critical for validating user uploads.
Go
Channels — Basics
Channels are typed pipes between goroutines. Unbuffered = synchronous handoff; buffered = up to N values queued. Close a channel to signal "no more values" — receivers see ok=false.
Rust
Custom Display + Debug Implementation
`Debug` (for `{:?}`) is usually derived. `Display` (for `{}`) is hand-written and goes through the same `std::fmt::Formatter` API.
Bash
Slice Bash Array
Bash supports Python-like array slicing via ${arr[@]:offset:length}. Lets you take/skip elements without external tools.
Kotlin
Compose Layout: Column, Row, Box
Compose's three fundamental layouts. `Column` stacks vertically, `Row` horizontally, `Box` overlays. Combine with `Modifier.weight()`, alignment, and arrangement for flexible UIs.
Kotlin
distinct, distinctBy, intersect, union
Set-style ops on collections. `distinct` removes duplicates; `distinctBy` lets you key the dedupe by a derived value; `union/intersect/subtract` give you set operations.
TypeScript
groupBy (with key callback)
Group a list into a record keyed by whatever the callback returns. Like Lodash _.groupBy or the new Object.groupBy in modern runtimes. Generic enough to handle string, number, or symbol keys.
Bash
Check If Array Contains Element
A pure-bash membership test using `=~` or by iterating. Both are useful — pick by readability vs. speed.
HTML
Search Form with Accessible Label
A search input usually has a visible-only icon — but screen readers need a real label. Pair a visually-hidden `<label>` with the icon, OR use `aria-label` on the input.
Bash
Clean Up Merged Branches
Delete every local branch that's been merged to main. Filters out main/master and the current branch as a safety net.
SQL
Pagination with LIMIT / OFFSET
`LIMIT N OFFSET M` is universal — but degrades on deep pages (the DB still has to scan past M rows). Keyset (cursor) pagination is much faster for huge tables.
HTML
Select with Optgroup
`<optgroup label="...">` visually groups options inside a `<select>`. Renders as a non-selectable header in every browser; screen readers announce the group as context.
Go
CSV Read/Write with encoding/csv
`encoding/csv` parses RFC 4180 CSVs. Read row-by-row with `Read()` or all at once with `ReadAll()`. Same for writing — flush with `Writer.Flush()` before closing.
Go
Struct Embedding (Composition over Inheritance)
Go has no inheritance. Embed a type to "promote" its fields and methods as if they were on the outer type. Same effect as inheritance for most purposes, but explicit.