Clojure REPL and tricks

lein repl :start :port 10010

(use 'clojure.repl 'clojure.pprint)

(setq nrepl-popup-stacktraces-in-repl nil)
(setq nrepl-auto-select-error-buffer nil)

Zoom

You can use `C-x C-+’ and ‘C-x C--’ (‘text-scale-adjust’) to increase or decrease the buffer text size (`C-+’ or ‘C--’ to repeat).

Very important: add cider plugin in project.clj

(defproject lucy "0.1.0-SNAPSHOT"
  :description "FIXME: write description"
  :url "http://example.com/FIXME"
  :license {:name "Eclipse Public License"
            :url "http://www.eclipse.org/legal/epl-v10.html"}
  :dependencies [
                 [org.clojure/clojure "1.6.0"]
                 [clucy "0.4.0"]
                 ]
  :plugins [[cider/cider-nrepl "0.6.0"]]
  )

In CIDER

C-c M-n: Set REPL namespace from buffer

C-x C-e: Eval preceding line

C-c C-k: compile buffer

C-x C-c: eval region

C-c C-c: abort eval

M-: Read a single Emacs Lisp expression in the minibuffer, evaluate it, and print the value in the echo area (eval-expression).

C-x h selects the entire buffer.

C-M-\ reindents the selected region.

C-M-@ select s-expression

M-. Jump to the definition of a symbol. If invoked with a prefix argument, or no symbol is found at point, prompt for a symbol.

M-@ (mark-word) puts the mark at the end of the next word

Use M-< to move to the beginning of the buffer, and M-> to move to the end

C-v to scroll down, and M-v to scroll up

M-d Kill up to the end of a word (kill-word).

M-\ Delete spaces and tabs around point (delete-horizontal-space)

M-<SPC> Delete spaces and tabs around point, leaving one space (just-one-space)

M-^ Join two lines by deleting the intervening newline, along with any indentation following it (delete-indentation)

C-t Transpose two characters (transpose-chars).

M-t Transpose two words (transpose-words).

C-M-t Transpose two balanced expressions (transpose-sexps).

C-x C-t Transpose two lines (transpose-lines).

M-x auto-revert-tail-mode (tail a file)

You can hide the *nrepl-connection* and *nrepl-server* buffers from appearing in some buffer switching commands like switch-to-buffer(C-x b) like this:
(setq nrepl-hide-special-buffers t)

---

M-% string <RET> newstring <RET>

Replace some occurrences of string with newstring.

C-M-% regexp <RET> newstring <RET>

Replace some matches for regexp with newstring.

---

<SPC>

to replace the occurrence with newstring.

<DEL>

to skip to the next occurrence without replacing this one.

, (Comma)

to replace this occurrence and display the result. You are then asked for another input character to say what to do next. Since the replacement has already been made, <DEL> and <SPC> are equivalent in this situation; both move to the next occurrence.You can type C-r at this point (see below) to alter the replaced text. You can also type C-x u to undo the replacement; this exits the query-replace, so if you want to do further replacement you must use C-x <ESC> <ESC> <RET> to restart (see Repetition).

<RET>

to exit without doing any more replacements.

. (Period)

to replace this occurrence and then exit without searching for more occurrences.

!

to replace all remaining occurrences without asking again.

Y (Upper-case)

to replace all remaining occurrences in all remaining buffers in multi-buffer replacements (like the Dired `Q' command which performs query replace on selected files). It answers this question and all subsequent questions in the series with "yes", without further user interaction.

N (Upper-case)

to skip to the next buffer in multi-buffer replacements without replacing remaining occurrences in the current buffer. It answers this question "no", gives up on the questions for the current buffer, and continues to the next buffer in the sequence.

^

to go back to the position of the previous occurrence (or what used to be an occurrence), in case you changed it by mistake or want to reexamine it.

---

Print object members

(doseq [m (.getMethods (type index))] (println m))

(use 'clojure.reflect 'clojure.pprint)

(pprint (reflect "hello"))

{:bases
 #{java.io.Serializable java.lang.Comparable java.lang.Object
   java.lang.CharSequence},
 :flags #{:public :final},
 :members
 #{{:name valueOf,
    :return-type java.lang.String,
    :declaring-class java.lang.String,...

List classpath

(defn classpath []

(seq (.getURLs (java.lang.ClassLoader/getSystemClassLoader))))

Expand macros

(macroexpand '(time (print "timing")))

;; or better yet

(clojure.pprint/pprint (macroexpand '(time 1)))

List members in namespace

(require '[clojure-hbase.core :as hbase])

(dir clojure-hbase.core)

Show function source

user=> (source hbase/table)
(defn table
  "Gets an HTable from the open HTablePool by name."
  [table-name]
  (io!
   (.getTable (htable-pool) (to-bytes table-name))))

Find elements by regex match in collection

(filter #(re-find #"zoo" (key %)) (seq (hbase/make-config nil)))

clojure.core/all-ns
  Returns a sequence of all namespaces.

List files

(take 10 (file-seq (clojure.java.io/file ".")))