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Languages & runtimes · #clojure
Stop creating intermediate collections in Clojure. Learn how transducers decouple transformation logic from data sources to improve performance and reusability.
Shows how to define specs, validate data at system edges, and use generative testing for confidence.
memoize cache expiration policy Goal: determine how to enforce a time‑to‑live (TTL) for entries returned by clojure.core/memoize . Constraints: memoize stores results in a mutable atom and never expires entries; no built‑in TTL or eviction strategy. Manual cache clearing is required, but the API does not expose a convenient mechanism for per‑key TTL or autom
Goal Determine whether a Clojure future can be cancelled when its deref operation times out, given that core.async timeout channels support cancellation by closing the channel while futures lack a built‑in cancellation API. Constraints and uncertainty The clojure.core/future macro starts a thread that cannot be stopped via a library function; deref with a ti
Interactive Element Standardization A ClojureScript project using Reagent needs to establish a standard for interactive UI controls. The goal is to maintain strict accessibility compliance while meeting specific design requirements that often conflict with default browser button styling. Native <button> elements provide inherent keyboard activation (En
Clojure 1.8.0 added direct linking through the :direct-linking key in *compiler-options* , replacing Var dereference call sites with direct function references. The default remains false , preserving runtime redefinition semantics that REPL-driven workflows rely on. For low-traffic or batch workloads that start frequently, enabling this feature can reduce al
State Management with Atoms Clojure Atoms utilize a Compare-And-Swap (CAS) mechanism to ensure thread-safe state transitions. The swap! function applies a transformation function to the current state and retries the operation if the state is modified by another thread before the commit completes. Performance Constraints While this lock-free approach prevents
The documented TTL cache type in clojure.core.cache associates each entry with an expiration threshold. The unresolved behavior is whether expiration is implemented as eager eviction or as a lazy filter applied on lookup, and how that choice is exposed by the cache API. The decision matters for consistency across access paths. A read-through helper typically
Clojure provides several primitives for managing shared mutable state, including Atoms, Refs (STM), and Agents. While Atoms are highly efficient for independent state changes using compare-and-swap (CAS) operations, they cannot coordinate updates across multiple variables atomically. The Software Transactional Memory (STM) system allows for coordinated chang