REPL Driven Mobile Development with Clojure(script)

Talk slides as presented in #FragmentsConf 2017.

Transcript

1. REPL Driven
   Mobile Development
   with Clojure(script)
   Srihari Sriraman | nilenso
   

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3. when did you become an expert
   in building mobile applications?
   last night, ofc
   

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4. I have leapfrogged
   

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5. Why I am speaking about this
   Using cljsrn, we built the
   same app as a native team
   faster, and better.
   

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6. The things I will talk about
   Why
   REPL Driven Development
   CLJSRN
   Non tech factors
   

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7. Parlance
   

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8. REPL
   Https://en.wikipedia.org/wiki/
   Read–eval–print_loop
   Read, Eval, Print, Loop
   “interactive computer programming
   environment that takes single expressions,
   evaluates them,
   and returns the result to the user.
   

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9. REPL
   Https://en.wikipedia.org/wiki/
   Read–eval–print_loop
   Read, Eval, Print, Loop
   

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10. Lisp
    http://lisp-lang.org/
    LISt Processor
    Second oldest HLL
    Homoiconic
    

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11. Lisp
    http://lisp-lang.org/
    LISt Processor
    Second oldest HLL
    Homoiconic
    

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12. Clojure
    https://clojure.org/
    Clojure is a dialect of Lisp
    that runs on the JVM
    

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13. Clojure
    https://clojure.org/
    Clojure is a dialect of Lisp
    Runs on the JVM
    Rich Hickey
    

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14. Clojure(script)
    http://clojurescript.org/
    ClojureScript is a compiler
    for Clojure that targets JavaScript
    David Nolen
    

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15. Clojure(script)
    http://clojurescript.org/
    ClojureScript is a compiler
    for Clojure that targets JavaScript
    David Nolen
    

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16. CLJSRN
    http://cljsrn.org
    ClojureScript is a compiler
    for Clojure that targets JavaScript.
    A framework for building native
    apps using React
    

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17. Feedback
    

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18. Bret Victor - Inventing on Principle
    https://vimeo.com/36579366
    “Most of my time is spent in code,
    working in a text editor blindly, without an
    immediate connection to what I'm trying to make."
    

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25. Bret Victor - Inventing on Principle
    https://vimeo.com/36579366
    “Creators need an immediate connection
    to what they create”
    

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26. Stephen Wolfram – Inside the Wolfram Language
    https://www.youtube.com/watch?v=EjCWdsrVcBM
    

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27. Ron Garret - Lisping at JPL
    http://www.flownet.com/gat/jpl-lisp.html
    “Debugging a program running on a $100M piece
    of hardware that is 100 million miles away is an
    interesting experience. Having a read-eval-print
    loop running on the spacecraft proved invaluable
    in finding and fixing the problem.”
    

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28. Sam Aaron –Programming Music with Overtone - Sam Aaron
    https://www.youtube.com/watch?v=imoWGsipe4k
    Zach Oakes –Making Games at Runtime with Clojure
    https://www.youtube.com/watch?v=0GzzFeS5cMc
    Me – Making machines that make music
    https://www.youtube.com/watch?v=ZvSSeuzN_b4
    Clojure land
    

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29. REPL Driven
    Development
    

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30. Clojurescript
    Clojure Compiler Javascript
    Google Closure Compiler
    Optimized Javascript RN flow
    How cljsrn gets to a mobile
    

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31. Demo
    

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32. What is a REPL?
    More than a Shell
    Interact with running program
    Define and modify behaviour
    Read and write access to program’s state
    In the editor
    

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33. Why use a REPL?
    Why Clojure REPL?
    Why CLJS?
    

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34. Why use a REPL?
    Feedback
    Explore and internalise the problem
    Incremental development of the solution
    Faster than TDD
    Debuggability
    

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35. Why use a Clojure REPL?
    60y of LISP
    Functions and Data structures, mostly
    Read, Eval, and Print are overridable functions
    Access to runtime: Reflections as data
    Namespaces, vars
    

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36. Why clojurescript?
    Expressive, Simple
    Seamless JS Interop
    Immutable data structures by default
    Google closure
    

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37. Expressive, Simple
    Javascript
    Clojurescript
    

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38. Why clojurescript?
    Expressive, Simple
    Seamless JS Interop
    Immutable data structures by default
    Google closure
    

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39. Seamless JS interop
    

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40. Why clojurescript?
    Expressive, Simple
    Seamless JS Interop
    Immutable data structures by default
    Google closure
    

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41. Why clojurescript?
    Expressive, Simple
    Seamless JS Interop
    Immutable data structures by default
    Google closure
    

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42. Tools
    figwheel: watchman++
    re-frame: SPA framework (predates elm, redux)
    core.async: no callback hell!
    

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43. Reservations
    Hiring: Lisps are very different
    Learning: Community is small
    

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44. Non tech factors
    

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46. Undivided Team
    Ability to have a full picture
    Quick feedback cycles
    Well defined APIs
    No Specialists
    

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47. Unilingual Team
    “Use the source”
    Share code
    Make PRs across FE and BE
    Shared tools, and release processes
    

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49. REPL Driven
    Mobile Development
    with Clojure(script)
    Srihari Sriraman | nilenso
    

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