Advanced terms
Reference Cycles and the gc Module
Python 3.4+
CPython uses reference counting for most cleanup, but circular references (A points to B, B points to A) require the cyclic garbage collector to detect and free them.
1mo ago
Python advanced
Rust Pin and Unpin
Pin<P> is a pointer wrapper that guarantees the pointed-to value will not move in memory, enabling safe self-referential types and async futures.
2mo ago
Rust advanced
Relation Extraction
4
Identifying semantic relationships between entity mentions in text, such as works-for or located-in, and emitting them as typed triples.
3mo ago
Knowledge Engineering advanced
Rust Unsafe Code
Unsafe blocks let you perform operations the borrow checker cannot verify, shifting memory-safety responsibility onto you.
4mo ago
Rust advanced
Rust Lifetime Annotations
Lifetime annotations tell Rust's borrow checker how long references must stay valid, preventing dangling references at compile time.
4mo ago
Rust advanced
Rust Macro System
Rust macros generate code at compile time through declarative pattern matching or procedural token manipulation, not runtime text substitution.
4mo ago
Rust advanced
Rust async/await
2
Rust's async/await syntax builds state-machine futures that run on an executor, enabling concurrency without blocking OS threads.
4mo ago
Rust advanced
Regex Conditional Patterns
PHP 4.0+
3
Conditional regex constructs like (?(1)yes|no) match different subpatterns depending on whether an earlier group captured.
4mo ago
Regex advanced
Register Allocation
PHP 8.0+
5
A compiler back-end pass that maps an unbounded set of virtual registers (or IR variables) to a finite set of physical CPU registers.
4mo ago
Compiler advanced
Regex Branch Reset Groups
2
A PCRE-specific construct (?|...) that resets capture group numbers across each alternative, so all branches share the same group indices.
5mo ago
Regex advanced
RLHF — Reinforcement Learning from Human Feedback
Post-training method where human preference rankings train a reward model that fine-tunes an LLM via reinforcement learning, aligning outputs with human preferences.
5mo ago
AI / ML advanced
Recursive Types
3.7 Types that reference themselves to describe arbitrarily nested structures — trees, nested menus, JSON, linked lists — without requiring any escape hatch.
6mo ago
TypeScript advanced
Raft Consensus Algorithm
A consensus algorithm designed to be understandable — Raft elects a leader who coordinates all writes, replicates log entries to followers, and ensures that committed entries are never lost even when servers fail.
6mo ago
Architecture advanced
Read Model Projections
Denormalised views of domain data built by processing event streams — the read side of CQRS, optimised for query performance rather than write consistency.
6mo ago
Architecture advanced
RoadRunner — Persistent PHP Worker
PHP 8.0+
Go-based server keeping PHP workers alive between requests — eliminating per-request bootstrap cost.
6mo ago
Performance advanced
Readonly Classes (PHP 8.2)
PHP 8.2+
Marking an entire class readonly makes all its properties implicitly readonly — ideal for immutable value objects and DTOs with minimal boilerplate.
6mo ago
PHP advanced
Reflection API
PHP 5.0+
PHP's built-in introspection system for examining classes, methods, properties, and parameters at runtime.
6mo ago
PHP advanced
Regex Performance
1
Regex performance pitfalls — catastrophic backtracking (ReDoS), unnecessary captures, and poorly anchored patterns that scan more input than needed.
6mo ago
Regex advanced
Retrieval-Augmented Generation (RAG)
1
A pattern that combines document retrieval with LLM generation — relevant documents are fetched and injected into the prompt context, grounding responses in current, specific data.
6mo ago
AI / ML advanced