clojure.core.memoize

core.memoize is a Clojure contrib library providing the following features:

• An underlying PluggableMemoization protocol that allows the use of customizable and swappable memoization caches that adhere to the synchronous CacheProtocol found in core.cache

• Memoization builders for implementations of common caching strategies, including:

  • First-in-first-out (clojure.core.memoize/fifo)
  • Least-recently-used (clojure.core.memoize/lru)
  • Least-used (clojure.core.memoize/lu)
  • Time-to-live (clojure.core.memoize/ttl)
  • Naive cache (memo) that duplicates the functionality of Clojure's memoize function but, unlike the built-in memoize function, ensures that in the case of concurrent calls with the same arguments, the memoized function is only invoked once; in addition memo can use metadata from the memoized function to ignore certain arguments for the purpose of creating the cache key, e.g., allowing you to memoize clojure.java.jdbc functions where the first argument includes a (mutable) JDBC Connection object by specifying :clojure.core.memoize/args-fn rest in the metadata

• Functions for manipulating the memoization cache of core.memoize backed functions

Releases and Dependency Information

This project follows the version scheme MAJOR.MINOR.COMMITS where MAJOR and MINOR provide some relative indication of the size of the change, but do not follow semantic versioning. In general, all changes endeavor to be non-breaking (by moving to new names rather than by breaking existing names). COMMITS is an ever-increasing counter of commits since the beginning of this repository.

Latest stable release: 1.0.236

• All Released Versions

• Development Snapshot Versions

CLI/deps.edn dependency information:

org.clojure/core.memoize {:mvn/version "1.0.236"}

Leiningen dependency information:

[org.clojure/core.memoize "1.0.236"]

Maven dependency information:

<dependency>
  <groupId>org.clojure</groupId>
  <artifactId>core.memoize</artifactId>
  <version>1.0.236</version>
</dependency>

Example Usage

    (ns my.cool.lib
      (:require clojure.core.memoize))

    (def id (clojure.core.memoize/lu
	          #(do (Thread/sleep 5000) (identity %))
			  :lu/threshold 3))

    (id 42)
    ; ... waits 5 seconds
    ;=> 42

    (id 42)
    ; instantly
    ;=> 42

Refer to docstrings in the clojure.core.memoize namespace for more information.

Developer Information

• GitHub project

• Bug Tracker

• Continuous Integration

• Compatibility Test Matrix

Change Log

• Release 1.0.next in progress
  • Clarify differences between clojure.core/memoize and clojure.core.memoize/memo functions CMEMOIZE-25.
• Release 1.0.236 on 2020.04.13
  • Switch to 1.0.x versioning CMEMOIZE-29.
  • Update core.cache dependency version from 0.8.2 to 1.0.207.
  • Fixes CMEMOIZE-9 - adds memo-reset! and deprecates 2-arity version of memo-swap!; adds 3+-arity version of memo-swap! to behave more like a swap! operation on the underlying cache
• Release 0.8.2 on 2019.11.01 (to match core.cache again)
  • Update core.cache dependency version from 0.7.2 to 0.8.2.
  • Fixes CMEMOIZE-28 - provides memoizer as a more convenient way to build custom cached functions that may provide a seed hash map of arguments to return values. build-memoizer should be considered deprecated at this point.
  • Fixes CMEMOIZE-27 - the seed function on PluggableMemoization now makes elements derefable (this case was missed when CMEMOIZE-18 was fixed)
• Release 0.7.2 on 2019.06.13
  • Fixes CMEMOIZE-26 - zero-arity function cache could not be replaced by memo-swap! (discovered by Teemu Kaukoranta)
  • Updated core.cache dependency version from 0.7.1 to 0.7.2
  • Updated test matrix locally to include Clojure 1.10.1, 1.11 master
• Release 0.7.1 on 2018.03.02
  • Fixes CMEMOIZE-15 - edge case where cache miss/lookup cross an eviction boundary (Ryan Fowler/Colin Jones)
  • Updated core.cache dependency version from 0.7.0 to 0.7.1 (for TTLCacheQ bug fix)
• Release 0.7.0 on 2018.03.01
  • Fixes CMEMOIZE-22 - add :clojure.core.memoize/args-fn metadata support for memoizing functions which have one or more arguments that should not contribute to the cache key for calls
  • Fixes CMEMOIZE-20 - add lazy-snapshot function
  • Fixes CMEMOIZE-18 - automatically makes seed map values deref-able to match documentation and comply with core.memoize's world view
  • Cleanup/improve/fix tests
  • Add multi-version testing locally via Leiningen
  • Jump to 0.7.0 to match core.cache since these two libraries are so closely in sync
• Release 0.5.9 on 2016.03.28
  • Updated core.cache dependency version from 0.6.4 to 0.6.5
• Release 0.5.8 on 2015.11.06
  • Fixes CMEMOIZE-21 - race condition in delay
• Release 0.5.7 on 2015.01.12
  • Fixes CMEMOIZE-8
  • Fixes CMEMOIZE-13
  • Updated core.cache dependency version from 0.6.3 to 0.6.4
• Release 0.5.6 on 2013.06.28
  • Added optional args to memo-clear!.
  • Widened contract on factory functions to accept any callable.
• Release 0.5.5 on 2013.06.14
  • Deprecated memo-* APIs
  • Adds new API of form (cache-type function <base><:cache-type/threshold int>)
• Release 0.5.4 on 2013.06.03
  • Fixes CMEMOIZE-5
  • Fixes CMEMOIZE-2
• Release 0.5.3 on 2013.03.18
  • Works with core.cache v0.6.3
• Release 0.5.2 on 2012.07.13
  • Works with core.cache v0.6.1
• Release 0.5.1 on 2011.12.13
  • Removed SoftCache memoization
• Release 0.5.0 on 2011.12.13
  • Rolled in basis of Unk

Copyright and License

Copyright (c) Rich Hickey and Michael Fogus, 2012, 2013. All rights reserved. The use and distribution terms for this software are covered by the Eclipse Public License 1.0 (https://opensource.org/licenses/eclipse-1.0.php) which can be found in the file epl-v10.html at the root of this distribution. By using this software in any fashion, you are agreeing to be bound bythe terms of this license. You must not remove this notice, or any other, from this software.