Importable clj-kondo configuration that discourages the use of several clojure.core functions or some of their arities that do lazy processing.
Requires at least v2025.02.20 of clj-kondo.
Add the following to your deps.edn, probably under a dev/test alias (the one you use to lint your code). Unless of course you're looking to re-export this config with your artifact, in which case it should probably go into its top-level deps.
imrekoszo/unlazy
{:git/url "https://github.com/imrekoszo/unlazy"
:git/tag "<see https://github.com/imrekoszo/unlazy/releases>"
:git/sha "<see https://github.com/imrekoszo/unlazy/releases>"}Alternatively just copy the parts you like into your own config.
Lazy processing is a powerful idea and is built into Clojure from the start. Using these functions is idiomatic and learning them is among the first steps most newcomers to the language take.
They do come with an overhead however which is not generally justified, and their behavior can be confusing in some cases. A great article explaining these is https://clojure-goes-fast.com/blog/clojures-deadly-sin/.
My recommendation is to only use lazy processing where absolutely necessary either for functionality or where it does deliver better performance. Personally I prefer transducers with carefully chosen transducible contexts so I can limit the amount of processing done.