From 8276ecb77286df1a79e040c0d33dae3741e10d39 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Jakub=20Hol=C3=BD?= Date: Sat, 30 Dec 2023 00:16:57 +0100 Subject: [PATCH] Clarify dev_startup_time w.r.t. already required nss It wasn't clear to me at all that compile only happens when loading a ns for the first time / force reloading it. HereI try to clarify this for the next person. --- content/guides/dev_startup_time.adoc | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/content/guides/dev_startup_time.adoc b/content/guides/dev_startup_time.adoc index 10304f4b..bb494355 100644 --- a/content/guides/dev_startup_time.adoc +++ b/content/guides/dev_startup_time.adoc @@ -24,12 +24,17 @@ The `compile` function takes a namespace symbol and compiles that namespace and Subsequently, when any of those compiled namespaces are required, the class file will be loaded, rather than the original `.clj` file. If a source file is updated (and thus newer), it will be loaded instead. Periodically, you will need to re-compile to account for new dependencies or changing code. -One special case is the `user.clj` file loaded automatically by the Clojure runtime, before any other code is loaded. If you are using a `user.clj` in dev, you need to force a reload because it has already been loaded automatically: +NOTE: Compilation happens as a side-effect of loading a namespace, and thus has no effect on already required ones. Use `*compile-files*` with `:reload-all` as suggested below to compile already loaded namespaces. + +One special case is the `user.clj` file loaded automatically by the Clojure runtime, before any other code is loaded. (Though this applies equally to compiling any namespace that has already been loaded into the REPL.) If you are using a `user.clj` in dev, you need to force a reload because it has already been loaded automatically: [source,clojure] ---- -(binding [*compile-files* true] (require 'user :reload-all)) +(binding [*compile-files* true] ; <1> + (require 'user :reload-all)) ; <2> ---- +<1> Tell Clojure to compile any namespace it is loading +<2> Tell Clojure to reload this and all required namespaces That's it! This technique can substantially reduce your startup time during development, particularly as the number of dependencies you load increases.