Clojure Repl
The Clojure REPL is a live environment in which your Clojure code runs. Using a REPL to develop your code gives you instant feedback on its behaviour and supports a rapidly evolving design. Clojure developers use the REPL to evaluate (run) a whole file of code or just a single expression.
All Clojure editors connect to an external REPL process, either connecting to an externally started REPL or starting the REPL from the editor.
| Approaches | Description |
|---|---|
| connect | flexible and robust approach supporting rich configurations, starting an external REPL via a command line terminal |
| jack-in | start an external REPL from the editor, injecting editor specific configuration and then connecting |
Practicalli recommends using the connect approach for all but the most simplest of workflows
Quick start
Open or select a Clojure buffer, this can be an .edn, .clj, .cljc or .cljs file.
| Key bindings | Description |
|---|---|
, ' or SPC m s |
sesman-start to start or connect to a REPL |
Select from one of the following types of REPL's
cider-connect-cljandcider-jack-in-cljfor Clojure on the JVMcider-connect-cljsandcider-jack-in-cljsfor a ClojureScript REPLcider-jack-in-clj&cljsto start a REPL of both types (full stack)
Once the REPL starts, evaluate expressions using the source code buffer.
REPL cheatsheet
SPC f f open a Clojure source code file from a project
, ' to start a Clojure REPL using Clojure CLI, Leiningen or Boot.
, e f evaluate the current Clojure expression and show the results inline
, e ; evaluate the current Clojure expression and show the results as a comment
SPC p a toggle between matching source code and unit test buffers
, e b evaluate all code from the current buffer within the REPL
, t a run all test functions in the REPL using the cider test runner
, m q r to restart the REPL (i.e. when adding a library as a dependency to the project)
Documentation enabled after evaluating a namespace
, h h shows the documentation for a function under the cursor, but only if a namespace has been evaluated first. This applies to clojure.core functions as well as project and library specific functions.