In this post I'll give updates about open source I worked on during March and April 2025.

To see previous OSS updates, go here.

Sponsors

I'd like to thank all the sponsors and contributors that make this work possible. Without you the below projects would not be as mature or wouldn't exist or be maintained at all! So a sincere thank you to everyone who contributes to the sustainability of these projects.

Current top tier sponsors:

• Clojurists Together
• Roam Research
• Nextjournal
• Nubank

Open the details section for more info about sponsoring.

Blog posts

I blogged about an important improvement in babashka regarding type hints here.

Interviews

Also I did an interview with Jiri from Clojure Corner by Flexiana, viewable here.

Updates

Here are updates about the projects/libraries I've worked on in the last two months.

• babashka: native, fast starting Clojure interpreter for scripting.

  • Improve Java reflection based on provided type hints (read blog post here)
  • Add compatibility with the fusebox library
  • Fix virtual ThreadBuilder interop
  • Add java.util.concurrent.ThreadLocalRandom
  • Add java.util.concurrent.locks.ReentrantLock
  • Add classes:
    • java.time.chrono.ChronoLocalDate
    • java.time.temporal.TemporalUnit
    • java.time.chrono.ChronoLocalDateTime
    • java.time.chrono.ChronoZonedDateTime
    • java.time.chrono.Chronology
  • #1806: Add cheshire.factory namespace (@lread)
  • Bump GraalVM to 24
  • Bump SCI to 0.9.45
  • Bump edamame to 1.4.28
  • #1801: Add java.util.regex.PatternSyntaxException
  • Bump core.async to 1.8.735
  • Bump cheshire to 6.0.0
  • Bump babashka.cli to 0.8.65

• clerk: Moldable Live Programming for Clojure

  • Replace tools.analyzer with a more light-weight analyzer which also adds support for Clojure 1.12

• squint: CLJS syntax to JS compiler

  • #653: respect :context expr in compile-string
  • #657: respect :context expr in set! expression
  • #659: fix invalid code produced for REPL mode with respect to return
  • #651 Support :require + :rename + allow renamed value to be used in other :require clause
  • Fix #649: reset ns when compiling file and fix initial global object
  • Fix #647: emit explicit null when written in else branch of if
  • Fix #640: don't emit anonymous function if it is a statement (@jonasseglare)
  • Fix #643: Support lexicographic compare of arrays (@jonasseglare)
  • Fix #602: support hiccup-style shorthand for id and class attributes in #jsx and #html
  • Fix #635: range fixes
  • Fix #636: add run!
  • defclass: elide constructor when not provided
  • Fix #603: don't emit multiple returns
  • Drop constructor requirement for defclass

• clj-kondo: static analyzer and linter for Clojure code that sparks joy.
  

  • #2522: support :config-in-ns on :missing-protocol-method
  • #2524: support :redundant-ignore on :missing-protocol-method
  • #1292: NEW linter: :missing-protocol-method. See docs
  • #2512: support vars ending with ., e.g. py. according to clojure analyzer
  • #2516: add new --repro flag to ignore home configuration
  • #2493: reduce image size of native image
  • #2496: Malformed deftype form results in NPE
  • #2499: Fix (alias) bug (@Noahtheduke)
  • #2492: Report unsupported escape characters in strings
  • #2502: add end locations to invalid symbol
  • #2511: fix multiple parse errors caused by incomplete forms
  • document var-usages location info edge cases (@sheluchin)
  • Upgrade to GraalVM 24
  • Bump datalog parser
  • Bump built-in cache

• SCI: Configurable Clojure/Script interpreter suitable for scripting

  • Fix #957: sci.async/eval-string+ should return promise with :val nil for ns form rather than :val <Promise>
  • Fix #959: Java interop improvement: instance method invocation now leverages type hints
  • Fix #942: improve error location of invalid destructuring
  • Add volatile? to core vars
  • Fix #950: interop on local in CLJS
  • Bump edamame to 1.4.28

• quickdoc: Quick and minimal API doc generation for Clojure

  • Fix #32: fix anchor links to take into account var names that differ only by case
  • Revert source link in var title and move back to <sub>
  • Specify clojure 1.11 as the minimal Clojure version in deps.edn
  • Fix macro information
  • Fix #39: fix link when var is named multiple times in docstring
  • Upgrade clj-kondo to 2025.04.07
  • Add explicit org.babashka/cli dependency

• CLI: Turn Clojure functions into CLIs!

  • #119: format-table now formats multiline cells appropriately (@lread)
  • Remove pom.xml and project.clj for cljdoc
  • #116: Un-deprecate :collect option to support custom transformation of arguments to collections (@lread)
  • Support :collect in :spec

• process: Clojure library for shelling out / spawning sub-processes

  • #163, #164: Program resolution strategy for exec and Windows now matches macOS/Linux/PowerShell (@lread)
  • Fix memory leak by executing shutdown hook when process finishes earlier than VM exit (@maxweber)

• html: Html generation library inspired by squint's html tag

  • Fix #3: allow dynamic attribute value: (html [:a {:a (+ 1 2 3)}])
  • Fix #9: shortcuts for id and classes

• cherry: Experimental ClojureScript to ES6 module compiler

  • Add cljs.pprint/pprint
  • Add add-tap
  • Bump squint compiler common which brings in new #html id and class shortcuts + additional features and optimizations, such as an optimization for aset

• nbb: Scripting in Clojure on Node.js using SCI

  • Add better Deno + jsr: dependency support, stay tuned.

• instaparse-bb: Use instaparse from babashka

  • Several improvements which makes babashka compatible with test.chuck. See this screenshot!

• edamame: Configurable EDN/Clojure parser with location metadata

  • #117: throw on triple colon keyword

• fs - File system utility library for Clojure

  • #141: fs/match doesn't match when root dir contains glob or regex characters in path
  • #138: Fix fs/update-file to support paths (@rfhayashi)

• sql pods: babashka pods for SQL databases

  • Upgrade to GraalVM 23, fixes encoding issue with Korean characters

Other projects

These are (some of the) other projects I'm involved with but little to no activity happened in the past month.