= Be a library developer!

: subtitle
   ((*R*))emember ((*t*))han ((*I*))magine

: author
   Kouhei Sutou
: institution
   ClearCode Inc.
: date
   2013/06/01
: allotted-time
   28m
: theme
   .

= Table of contents

  * Share this talk's goal
  * Describe key idea
  * Apply the key idea
  * Wrap up & The next step

= Share the goal

  * ((*Share this talk's goal*))
  * Describe key idea
  * Apply the key idea
  * Wrap up & The next step

= This talk's goal

(('tag:as-large-as-possible'))
You know\nhow to develop better softwares

= Better?

Show\nby example

= API

  # coderay ruby
  context.save
  context.circle(50, 50, 10)
  context.stroke
  context.restore

(('tag:center'))(('note:from cairo gem'))

== slide property

: evaluate-code
   true

= API: Point

  # coderay ruby
  context.save    # <- Point
  context.circle(50, 50, 10)
  context.stroke
  context.restore # <- Point

(('tag:center'))(('note:from cairo gem'))

== slide property

: evaluate-code
   true

= API: Better

  # coderay ruby
  context.save do
  context.circle(50, 50, 10)
  context.stroke
  end

(('tag:center'))(('note:from cairo gem'))

== slide property

: evaluate-code
   true

= API: Why

Why is it better?

= API: Because

Because it's more Ruby-ish

= Ruby-ish?

-ish ==\n
Similar to others

= Is "similar" better?

  * Similarity makes consistency
  * Consistency makes readability
  * Readability is important to develop better softwares

= Is "readability" important?

  * Readability makes maintenability

  * Maintenability is needed for 
    improving your softwares repeatedly

= So

Ruby-ish is\nbetter

= Let's validate the example

= Remember

File

= Remember: File

  # coderay ruby
  # Setup
  file = File.open(path)
  file.read
  # Teardown
  file.close

= Remember: File

  # coderay ruby
  # Setup
  File.open(path) do |file|
    file.read
  end # Teardown

= API (reprise)

  # coderay ruby
  context.save    # Setup     
  context.circle(50, 50, 10)
  context.stroke
  context.restore # Teardown  

(('tag:center'))(('note:from cairo gem'))

== slide property

: evaluate-code
   true

= API: Better (reprise)

  # coderay ruby
  context.save do # Setup     
    context.circle(50, 50, 10)
    context.stroke
  end             # Teardown  

(('tag:center'))(('note:from cairo gem'))

== slide property

: evaluate-code
   true

= Wrap up

= Better

Ruby-ish

= In other words

Similar to others

= The goal (reprise)

(('tag:as-large-as-possible'))
You know\nhow to develop better softwares

= In other words

(('tag:as-large-as-possible'))
You know\nwhat is "similar" and do similarly

= Describe key idea

  * Share this talk's goal
  * ((*Describe key idea*))
  * Apply the key idea
  * Wrap up & The next step

= Key idea

(('tag:left'))
(('tag:margin-left * 10'))
((*R*))emember\n((*t*))han\n((*I*))magine

= Remember than Imagine

  # image
  # src = remember-than-imagine.svg
  # relative_height = 100

== slide property

: enable-title-on-image
   false

= To remember,

  # image
  # src = to-remember.svg
  # relative_height = 100

== slide property

: enable-title-on-image
   false

= How to get knowledge?

  * Experience
  * Ask
  * Observe

= Experience!

  * ((*Experience*)) ← Do this first!
  * Ask
  * Observe

= Key idea

(('tag:left'))
(('tag:margin-left * 10'))
((*R*))emember\n((*t*))han\n((*I*))magine

= Apply the key idea

  * Share this talk's goal
  * Describe key idea
  * ((*Apply the key idea*))
  * Wrap up & The next step

= The goal (reprise)

(('tag:as-large-as-possible'))
You know\nhow to develop better softwares

= Apply the key idea

  # image
  # src = apply-key-idea.svg
  # relative_height = 100

== slide property

: enable-title-on-image
   false

= To achieve the goal,

What should you experience?

= What experience?

  # image
  # src = what-experience.svg
  # relative_height = 100

== slide property

: enable-title-on-image
   false

= Rubyist

  # image
  # src = rubyist-experience.svg
  # relative_height = 100

== slide property

: enable-title-on-image
   false

= Rubyist?

You experienced!

= Try

= API: Getter

  # coderay ruby
  window.get_property("opacity")
  # What is better API???

(('tag:center'))(('note:from gtk2 gem'))

= API: Getter (better)

  # coderay ruby
  window.get_property("opacity")
  window.opacity # Better

(('tag:center'))(('note:from gtk2 gem'))

= Now,

(('tag:as-large-as-possible'))
You found "remember" is "difficult"

= Difficult!

Remember!?\n
What is\n"Ruby-ish"!?

= Difficult?

  # image
  # src = remember-is-difficult.svg
  # relative_height = 100

== slide property

: enable-title-on-image
   false

= Because

(('tag:as-large-as-possible'))
You don't have experience about\n
"((*R*))emember ((*t*))han ((*I*))magine"

= No "remember" experience

  # image
  # src = no-remember-experience.svg
  # relative_height = 100

== slide property

: enable-title-on-image
   false

= Your status

  * Experience
  * ((*Ask*)) (Heard) ← You are here!
  * Observe

= To achieve the goal,

What should you experience?

= What experience?

  # image
  # src = what-experience-to-remember.svg
  # relative_height = 100

== slide property

: enable-title-on-image
   false

= Library developer

  # image
  # src = library-developer-experience.svg
  # relative_height = 100

== slide property

: enable-title-on-image
   false

= Library developer

Considers about
  * easy to use API
    * as a Rubyist
  * easy to understand document
    * as a library user

= Library developer

Considers them ((*many times*))

= "Many times"

It's very good exercise

= Exercises

  * API
  * Document

= API

= API: Getter (reprise)

  # coderay ruby
  # Low level
  window.get_property("opacity")
  # Better
  window.opacity

(('tag:center'))(('note:from gtk2 gem'))

= API: Better?

  # coderay ruby
  # Low level
  window.get_property("visible")
  # Better
  # ???: hint: "visible" is bool

(('tag:center'))(('note:from gtk2 gem'))

= API: Better

  # coderay ruby
  # Low level
  window.get_property("visible")
  # Better
  window.visible?

(('tag:center'))(('note:from gtk2 gem'))

= API: Getter

  # coderay ruby
  # Better for record as collection
  record["name"]
  # Better for record as object
  record.name

(('tag:center'))(('note:from rroonga gem'))

= API: Init

  # coderay ruby
  require "gst"
  # ???
  Gst.init # <- What?
  Gst::ElementFactory.make("playbin")

(('tag:center'))(('note:from gstreamer gem'))

= API: Init (usage)

  # coderay ruby
  require "gst"
  # For advanced use
  Gst.init("--gst-debug=*:9")
  Gst::ElementFactory.make("playbin")

(('tag:center'))(('note:from gstreamer gem'))

= API: Init (better)

   # coderay ruby
   require "gst"
   # Make optional
   # Gst.init
   Gst::ElementFactory.make("playbin")

(('tag:center'))(('note:from gstreamer gem'))

= API: Init (impl)

  # coderay ruby
  class << Gst
    def const_missing(name)
      init; const_get(name); end
    def init(*argv)
      # ...initialize library...
      class << self
        remove_method(:const_missing)
      end; end; end

(('tag:center'))(('note:from gstreamer gem'))

= Document

= Document: Install

Install:

  For Debian GNU/Linux:
    % sudo apt-get install libgtk2.0-dev
    % gem install gtk2
  For OS X:
    ...

= Document: Better

Install:

  % gem install gtk2

(('tag:center'))(('note:libgtk2-0-dev is installed automatically'))

(('tag:center'))(('note:"gem install GEM_NAME" is popular install way'))

= Exercises end

  * We remembered about\n
    "what is similar?"
  * We done "similarly"

= Do you understand about\n"((*R*))emember ((*t*))han ((*I*))magine"?

= Wrap up

  * Share this talk's goal
  * Describe key idea
  * Apply the key idea
  * ((*Wrap up*)) & The next step

= This talk's goal

(('tag:as-large-as-possible'))
You know\nhow to develop better softwares

= Better

Ruby-ish\n
Similar to others

= Goal: In other words

(('tag:as-large-as-possible'))
You know\nwhat is "similar" and do similarly

= Key idea

(('tag:left'))
(('tag:margin-left * 10'))
((*R*))emember\n((*t*))han\n((*I*))magine

= Remember than Imagine

  # image
  # src = remember-than-imagine.svg
  # relative_height = 100

== slide property

: enable-title-on-image
   false

= For development

  * Experience Rubyist for ((*knowledge*))
  * Then ((*remember*)) the knowledge
    * But it is difficult because 
      you don't have experience about "((*remember*))"

= No "remember" experience

  # image
  # src = no-remember-experience.svg
  # relative_height = 100

== slide property

: enable-title-on-image
   false

= Experience lib developer

It's very good exercise

= The next step

  * Share this talk's goal
  * Describe key idea
  * Apply the key idea
  * Wrap up & ((*The next step*))

= The next step

Use "library developer" experience to other things

= For example,

Use it to develop other softwares

= Develop other softwares

You can remember about
  * a better bug report
    * How to reproduce?
  * a better patch
    * How to commit? (size? message?)

= Conclusion

Be a library developer!

= FYI

    # image
    # src = clear-code.svg
    # relative_height = 20

  * We accept applications about our internship
    * You can develop a library with us

= Bonus tracks

  * Similar vs. Innovation
  * No "imagine" communication\n

= Similar\nvs.\nInnovation

= Innovation

  * Doing "similarly" will not achieve "innovation"
  * Should all we aspire innovation?

= No

  * We have regular life
  * It's also important that\n
    we improve our regular life

= No\n"imagine" communication

= No "imagine"

  * Show all u need from the start
    * Don't omit anything
    * If you emit something,\n
      other people need "imagine"
  * Use your experience for it!

= Key idea

(('tag:left'))
(('tag:margin-left * 10'))
((*R*))emember\n((*t*))han\n((*I*))magine