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
   

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2. Sveiki!
   

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3. į sveikatą!
   

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4. @bbatsov
   

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5. Bulgaria
   

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7. Bug
   

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10. A (Dark) Knight of
    the
    Order of Emacs
    

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13. Why I am here?
    

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14. I am a storyteller!
    

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15. View Slide

16. A story about a different kind
    of cider…
    

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17. Which is your primary Clojure dev
    environment? (2014)
    Other
    13%
    LightTable
    12%
    CCW
    5%
    fireplace
    14% Cursive
    14%
    CIDER
    42%
    

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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.”
    

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19. Near future
    Others
    10%
    CIDER
    90%
    

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20. Near future
    Cursive
    25%
    Others
    15%
    CIDER
    60%
    

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21. A not so long time ago in a
    galaxy not far away…
    

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22. Java, C# and PHP ruled the
    dev world
    

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23. The Lisp Masters from the
    Republic of Great Programmers
    were on the run
    

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24. Lisps were out of
    fashion
    

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26. A gentleman
    &
    a scholar
    

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27. Clojure
    

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28. Biggest Clojure problem at
    launch?
    

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29. ((((((((((()))))))))))
    

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30. 0
    Clojure
    development
    environments
    

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31. Emacs was the last Lisp
    stronghold
    

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32. Emacs is the greatest Emacs
    Lisp dev environment
    

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33. SLIME
    

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34. Superior
    Lisp
    Interaction
    Mode for
    Emacs
    

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35. SLIME Features
    • REPL
    • Interactive evaluation
    • Compilation notes
    • Code completion
    • Definition lookup
    • Documentation lookup
    • Apropos
    

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36. SLIME Features
    • Debugger
    • Value inspector
    • Tracing
    • Find usages
    • Macroexpansion
    • Scratchpad
    • Minibuffer code evaluation
    

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37. SLIME is an IDE
    

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38. Interactive Development
    Environment
    

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39. Programs are built in a very
    incremental manner
    

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40. SLIME
    (Emacs Lisp)
    SWANK
    (Common Lisp)
    Clozure
    RPC
    LispWorks
    CMUCL
    ABCL
    SBCL
    Client Server Backends
    

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42. clojure-mode
    &
    swank-clojure
    

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43. SLIME
    (Emacs Lisp)
    SWANK
    (Common Lisp)
    swank-clojure
    

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44. A star was born
    

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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)
    

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46. SLIME is a
    Common Lisp
    tool
    

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48. Another esteemed
    gentleman
    &
    scholar
    

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49. nREPL
    

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50. A common foundation
    for Clojure development tools
    

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51. •Load (compile) a Clojure source file
    •Evaluate a Clojure form
    •Interrupt evaluation
    •Read from the standard input
    

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52. Extensible via middleware
    

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54. nrepl.el
    

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55. nrepl.el
    (Emacs Lisp)
    nREPL
    (Clojure)
    

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56. A workhorse is retired
    

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57. nrepl.el
    • lacked many SLIME features
    • relied heavily on evaluation of inlined code
    • made assumptions about the environment
    • flawed bencode parser
    

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59. Don’t settle for good.
    Demand great!
    

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60. –Phil Karlton
    “There are only two hard things in
    Computer Science: cache invalidation
    and naming things.”
    

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62. Clojure
    Integrated
    Development
    Environment &
    REPL
    

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63. Clojure
    Interactive
    Development
    Environment
    Reimagined
    

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64. Clojure
    Interactive
    Development
    Environment that
    Rocks
    

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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
    

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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
    

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68. CIDER Features
    • Interactive evaluation
    • Compilation notes
    • Code completion
    • Definition lookup
    • Documentation lookup
    • Apropos
    

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69. CIDER Features
    • Value inspector
    • Command selector
    • Tracing
    • Macroexpansion
    • Debugger
    • Scratchpad
    • Minibuffer code evalution
    

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70. CIDER Features
    • Javadoc support
    • Jump to Java definition
    • Jump to resource
    • Sanity-preserving stacktraces
    • clojure.test integration
    • namespace browser
    

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71. CIDER Features
    • classpath browser
    • grimoire integration
    • dynamic indentation
    • dynamic font-locking
    • nREPL session manager
    • Smart namespace reloading
    • ClojureScript support
    

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72. Extensions
    (are easy)
    

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73. Refactoring support
    (clj-refactor + refactor-nrepl)
    

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74. Demo Time
    

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75. CIDER
    tastes better than
    SLIME
    

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76. CIDER
    tastes better than
    some IDES
    

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77. What’s still missing?
    

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78. • Find usages
    • Built-in refactoring tooling
    • Better ClojureScript support
    • Support for the new Clojure socket REPL
    • A proper manual
    CIDER 1.0
    

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79. Why CIDER?
    

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80. Integrated Development
    Environment (a.k.a. IDE)
    

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82. Emacs
    

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88. Spacemacs
    

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89. Emacs users
    know how to build productive
    Lisp workflows
    

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90. •Emacs (ultimate Elisp dev env)
    •SLIME (and SLY)
    •Geiser
    •racket-mode
    •CIDER (obviously)
    

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91. • paredit
    • smartparens
    • rainbow-delimiters
    • rainbow-identifiers
    • sexp-fu
    • paxedit
    • lispy
    

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92. Community impact
    

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93. cider-nrepl
    https://github.com/clojure-emacs/cider-nrepl
    

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94. refactor-nrepl
    https://github.com/clojure-emacs/refactor-nrepl
    

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95. compliment
    https://github.com/alexander-yakushev/compliment
    

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96. cljs-tooling
    https://github.com/gtrak/cljs-tooling
    

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97. nREPL improvements
    

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98. Open development
    

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101. 126 contributors!
     

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102. Please, send more help!
     

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103. Thanks!
     

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104. Felina
     

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