Getting Started with Cider for Clojure Programming

C-c M-j (cider-jack-in-clj)

start a nREPL and jack in. It works in a project or with a sole .clj file.

M-x cider-connect-clj

run the command and then fill in hostname and port. It could be useful in some cases. e.g. on Windows, I can start the nREPL manually and then connect to it separately.

C-M-x (cider-eval-defun-at-point)

evaluate current top-level form.

C-x C-e (cider-eval-last-sexp)

evaluate the preceding form.

C-c C-k (cider-load-buffer)

evaluate/load the current buffer.

C-c C-p (cider-pprint-eval-last-sexp)

Pprint the result in a dedicated buffer. Great thing to do when the result is too large to fit in the echo area.

Note: I prefer to use the same key bindings as for Elisp, given that cider might bind a few keys to a single command!

• Type TAB or M-TAB to manually triger completion, which I rarely use
• Instead, use company-mode to do auto-completion

These are based on the xref interface:

M-. (xref-find-definitions)

jump into a symbol's definition

M-, (xref-go-back)

jump back

Showing function signatures on the echo area (eldoc-mode)

C-c C-d C-d (cider-doc)

lookup docs for the current symbol

C-u C-c C-d C-d

Prefix it with C-u to manually specify a symbol to look up

C-c C-z (cider-switch-to-repl-buffer)

switch back and forth between a code and the REPL buffers

C-u C-c C-z

prefix the command to change REPL's ns to the current buffer's as well.

We can also use (comment ...) to do some experiments.

• Debugging
• Running Tests
• Code Reloading
• Pretty Printing
• JavaDoc/ClojureDoc lookup

Head over https://cider.mx/ for details.