CIDER: Rocking with Clojure and Emacs

Slide deck from my buildstuff.lt 2015 presentation.

Transcript

1. CIDER: Rocking with Clojure and Emacs narrated by Bozhidar I. Batsov
2. Sveiki!
3. į sveikatą!
4. @bbatsov
5. Bulgaria
7. Bug
10. A (Dark) Knight of the Order of Emacs
13. Why I am here?
14. I am a storyteller!
16. A story about a different kind of cider…
17. Which is your primary Clojure dev environment? (2014) Other 13% LightTable 12% CCW 5% fireplace 14% Cursive 14% CIDER 42%
18. –Nancy Pearcey “Competition is always a good thing. It forces us to do our best. A monopoly renders people complacent and satisfied with mediocrity.”
19. Near future Others 10% CIDER 90%
20. Near future Cursive 25% Others 15% CIDER 60%
21. A not so long time ago in a galaxy not far away…
22. Java, C# and PHP ruled the dev world
23. The Lisp Masters from the Republic of Great Programmers were on the run
24. Lisps were out of fashion
26. A gentleman & a scholar
27. Clojure
28. Biggest Clojure problem at launch?
29. ((((((((((()))))))))))
30. 0 Clojure development environments
31. Emacs was the last Lisp stronghold
32. Emacs is the greatest Emacs Lisp dev environment
33. SLIME
34. Superior Lisp Interaction Mode for Emacs
35. SLIME Features • REPL • Interactive evaluation • Compilation notes • Code completion • Definition lookup • Documentation lookup • Apropos
36. SLIME Features • Debugger • Value inspector • Tracing • Find usages • Macroexpansion • Scratchpad • Minibuffer code evaluation
37. SLIME is an IDE
38. Interactive Development Environment
39. Programs are built in a very incremental manner
40. SLIME (Emacs Lisp) SWANK (Common Lisp) Clozure RPC LispWorks CMUCL ABCL SBCL Client Server Backends
42. clojure-mode & swank-clojure
43. SLIME (Emacs Lisp) SWANK (Common Lisp) swank-clojure
44. A star was born
45. swank-clojure • Requires knowledge of swank (Common Lisp) • Bundles a frozen SLIME version • Subpar features (e.g. debugger, inspector, find usages) • Monolithic (no swank plugins)
46. SLIME is a Common Lisp tool
48. Another esteemed gentleman & scholar
49. nREPL
50. A common foundation for Clojure development tools
51. •Load (compile) a Clojure source file •Evaluate a Clojure form •Interrupt evaluation •Read from the standard input
52. Extensible via middleware
54. nrepl.el
55. nrepl.el (Emacs Lisp) nREPL (Clojure)
56. A workhorse is retired
57. nrepl.el • lacked many SLIME features • relied heavily on evaluation of inlined code • made assumptions about the environment • flawed bencode parser
59. Don’t settle for good. Demand great!
60. –Phil Karlton “There are only two hard things in Computer Science: cache invalidation and naming things.”
62. Clojure Integrated Development Environment & REPL
63. Clojure Interactive Development Environment Reimagined
64. Clojure Interactive Development Environment that Rocks
66. (defun nrepl-jump-to-def (var) "Jump to the definition of the VAR at point." (let ((form (format "(let [ns-symbol '%s ns-var '%s ns-file (clojure.core/comp :file clojure.core/meta clojure.core/second clojure.core/first clojure.core/ns-publics) resource-str (clojure.core/comp clojure.core/str clojure.java.io/resource ns-file) file-str (clojure.core/comp clojure.core/str clojure.java.io/file ns-file)] (cond ((clojure.core/ns-aliases ns-symbol) ns-var) (let [resolved-ns ((clojure.core/ns-aliases ns-symbol) ns-var)] [(resource-str resolved-ns) (file-str resolved-ns) 1]) (find-ns ns-var) [(resource-str ns-var) (file-str ns-var) 1] (clojure.core/ns-resolve ns-symbol ns-var) ((clojure.core/juxt (clojure.core/comp clojure.core/str clojure.java.io/resource :file) (clojure.core/comp clojure.core/str clojure.java.io/file :file) :line) (clojure.core/meta (clojure.core/ns-resolve ns-symbol ns-var)))))" (nrepl-current-ns) var))) (nrepl-send-string form (nrepl-jump-to-def-handler (current-buffer)) nrepl-buffer-ns (nrepl-current-tooling-session)))) not portable
67. (defun cider-jump-to-var (&optional var line) "Jump to the definition of VAR, optionally at a specific LINE. When called interactively, this operates on point, or falls back to a prompt." (interactive) (cider-ensure-op-supported "info") (cider-read-symbol-name "Symbol: " (lambda (var) (-if-let (info (cider-var-info var)) (cider--jump-to-loc-from-info info) (message "Symbol %s not resolved" var))))) portable
68. CIDER Features • Interactive evaluation • Compilation notes • Code completion • Definition lookup • Documentation lookup • Apropos
69. CIDER Features • Value inspector • Command selector • Tracing • Macroexpansion • Debugger • Scratchpad • Minibuffer code evalution
70. CIDER Features • Javadoc support • Jump to Java definition • Jump to resource • Sanity-preserving stacktraces • clojure.test integration • namespace browser
71. CIDER Features • classpath browser • grimoire integration • dynamic indentation • dynamic font-locking • nREPL session manager • Smart namespace reloading • ClojureScript support
72. Extensions (are easy)
73. Refactoring support (clj-refactor + refactor-nrepl)
74. Demo Time
75. CIDER tastes better than SLIME
76. CIDER tastes better than some IDES
77. What’s still missing?
78. • Find usages • Built-in refactoring tooling • Better ClojureScript support • Support for the new Clojure socket REPL • A proper manual CIDER 1.0
79. Why CIDER?
80. Integrated Development Environment (a.k.a. IDE)
82. Emacs
88. Spacemacs
89. Emacs users know how to build productive Lisp workflows
90. •Emacs (ultimate Elisp dev env) •SLIME (and SLY) •Geiser •racket-mode •CIDER (obviously)
91. • paredit • smartparens • rainbow-delimiters • rainbow-identifiers • sexp-fu • paxedit • lispy
92. Community impact
93. cider-nrepl https://github.com/clojure-emacs/cider-nrepl
94. refactor-nrepl https://github.com/clojure-emacs/refactor-nrepl
95. compliment https://github.com/alexander-yakushev/compliment
96. cljs-tooling https://github.com/gtrak/cljs-tooling
97. nREPL improvements
98. Open development
101. 126 contributors!
102. Please, send more help!
103. Thanks!
104. Felina