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palkan_tula
palkan
Why is Ruby
impressive?
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ͳͥRuby͍͢͝ͷ͔
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palkan_tula
palkan
h = {x:, y:}
def foo(&) bar(&)
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2015 2018 2019 2020 2021 2022 2024
1...
&.
...1
case ... in
def x = 1
def foo(*) bar(*)
1 in x
proc { it }
def foo(...)
proc { _1 }
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palkan_tula
palkan
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2024 2025 2026 2027 2028 2029 2030
proc { it }
??
??
??
??
??
??
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palkan_tula
palkan
–D. Crystal
“The only languages which do
not change are dead ones”
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มΘΒͳ͍ݴޠࢮΜͩݴޠͰ͢ɻ
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palkan_tula
palkan
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2024 2025 2026 2027 2028 2029 2030
proc { it }
??
??
??
??
??
??
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palkan_tula
palkan
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2024 2025 2026 2027 2028 2029 2030
proc { it } ??
??
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palkan_tula
palkan
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2013 2015 2017 2019 2020 2021
&.
proc { it }
2024
proc { it }
&.
h = {x:, y:}
case ... in
case ... in
h = {x:, y:}
def x = 1
def x = 1
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palkan_tula
palkan
Adding new syntax
is irreversible
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৽͍͠จ๏Λಋೖ͢ΔͱޙΓͰ͖ͳ͍
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palkan_tula
palkan
How to predict new
syntax benefits?
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৽͍͠จ๏ͷϝϦοτΛͲ͏༧ଌ͢Δ͔
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palkan_tula
palkan
I. Encourage early adopters to
experiment with proposals.
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ΞʔϦʔΞμϓλʔʹ৽نఏҊͰ࣮ݧͯ͠Β͏
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palkan_tula
palkan
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RubyKaigi
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RubyWasmKaigi
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github.com/palkan
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evilmartians.com
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urlgeni.us/amazon/Rails-book
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LET'S START MIXING
ʮ࢝ΊΑ͏ʂʯ
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palkan_tula
palkan
I. Encourage early adopters to
experiment with proposals.
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ΞʔϦʔΞμϓλʔʹ৽نఏҊͰ࣮ݧͯ͠Β͏
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palkan_tula
palkan
I. Encourage early adopters to
experiment with proposals.
II. Learn from other languages.
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ΞʔϦʔΞμϓλʔʹ৽نఏҊͰ࣮ݧͯ͠Β͏
ଞͷݴޠΛࢀߟʹ͢Δ
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palkan_tula
palkan
h = {x:, y:}
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palkan_tula
palkan
h = {x:, y:}
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palkan_tula
palkan
h = {x:, y:}
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palkan_tula
palkan
1
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palkan_tula
palkan
user["name"] = user["name"] ?: "Guest"
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PHP:
$user['name'] ??= 'Guest'
Kotlin:
JavaScript:
user.name ??= 'guest'
Elvis operator
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palkan_tula
palkan
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palkan_tula
palkan
! → "
SyntaxError
Use cases
Implementation
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࣮
Ϣʔεέʔε
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palkan_tula
palkan
?=
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palkan_tula
palkan
$
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ruby -e 'a ?= 1'
-e:1: syntax error, unexpected integer literal,
expecting end-of-input
a ?= 1
-e: compile error (SyntaxError)
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palkan_tula
palkan
?=
a = nil
a ?= false # a is false
a ?= 1 # a is false
a ||= 1 # a is 1
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palkan_tula
palkan
Use cases
I. (a = false) ?= 2024 #=> false
...
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Ϣʔεέʔε
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palkan_tula
palkan
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palkan_tula
palkan
45
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palkan_tula
palkan
?= ❤ Hash
h = {val: nil}
# h[:val] = 42 unless h.key?(:val)
h[:val] ?= 42
h #=> {val: nil}
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palkan_tula
palkan
?= ❤ @var
def current_user
return @current_user if defined?(@current_user)
@current_user = find_user
end
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palkan_tula
palkan
def current_user
@current_user ?= find_user
end
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def current_user
return @current_user if defined?(@current_user)
@current_user = find_user
end
?= ❤ @var
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palkan_tula
palkan
def current_user
@current_user ?= find_user
end
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def current_user
return @current_user if defined?(@current_user)
@current_user = find_user
end
?= ❤ @var
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palkan_tula
palkan
ΦϒδΣΫτγΣΠϓ
def current_user
@current_user ?= find_user
end
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def current_user
return @current_user if defined?(@current_user)
@current_user = find_user
end
$ Object shapes :(
?= ❤ @var
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palkan_tula
palkan
I. (a = false) ?= 2024 #=> false
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Use cases
Ϣʔεέʔε
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palkan_tula
palkan
I. (a = false) ?= 2024 #=> false
II. h[:x] ?= 5
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Use cases
Ϣʔεέʔε
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palkan_tula
palkan
I. (a = false) ?= 2024 #=> false
II. h[:x] ?= 5
III. @value ?= maybe_some
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Use cases
Ϣʔεέʔε
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palkan_tula
palkan
εϚʔτΦϒδΣΫτγΣΠϓ
I. (a = false) ?= 2024 #=> false
II. h[:x] ?= 5
III. @value ?= maybe_some
⏳ Smart object shapes
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Use cases
Ϣʔεέʔε
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palkan_tula
palkan
?= → ❤
SyntaxError
Use cases
Implementation
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࣮
Ϣʔεέʔε
→ lexer, parser
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palkan_tula
palkan
3
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palkan_tula
palkan
def beach(*temperature)
case temperature
in :celcius | :c, (20..45)
:favorable
in :kelvin | :k, (293..318)
:scientifically_favorable
in :fahrenheit | :f, (68..113)
:favorable_in_us
else
:avoid_beach
end
end
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palkan_tula
palkan
beach(Temperature) ->
case Temperature of
{celsius, N} when N >= 20, N =< 45 ->
'favorable';
{kelvin, N} when N >= 293, N =< 318 ->
'scientifically favorable';
{fahrenheit, N} when N >= 68, N =< 113 ->
'favorable in the US';
_ ->
'avoid beach'
end.
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palkan_tula
palkan
beach({celsius, N}) when N >= 20, N =< 45 ->
'favorable';
beach({kelvin, N}) when N >= 293, N =< 318 ->
'scientifically favorable';
beach({fahrenheit, N}) when N >= 68, N =< 113 ->
'favorable in the US';
beach(_) ->
'avoid beach'.
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palkan_tula
palkan
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palkan_tula
palkan
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palkan_tula
palkan
def beach(*temperature)
case temperature
in :celcius | :c, (20..45)
:favorable
in :kelvin | :k, (293..318)
:scientifically_favorable
in :fahrenheit | :f, (68..113)
:favorable_in_us
else
:avoid_beach
end
end
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palkan_tula
palkan
def beach in :celcius | :c, (20..45)
:favorable
end
def beach in :kelvin | :k, (293..318)
:scientifically_favorable
end
def beach in :fahrenheit | :f, (68..113)
:favorable_in_us
end
def beach(...) = :avoid_beach
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palkan_tula
palkan
$
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ruby -e 'def foo in :c, Integer => v; v; end'
-e:1: syntax error, unexpected `in', expecting ';'
or '\n'
def foo in :c, Integer => v; v; end
-e: compile error (SyntaxError)
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palkan_tula
palkan
def ... in
No new keywords
Resembles other languages
(Elixir, Crystal, etc.)
Idiomatic Ruby &
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৽͍͠ΩʔϫʔυΛ૿͞ͳ͍
ଞͷݴޠʹࣅͤΔ
Ruby ͷΠσΟΦϜʹै͏
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palkan_tula
palkan
foo(*args) — '
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palkan_tula
palkan
foo(*args) — '
foo(**kwargs) — '
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palkan_tula
palkan
foo(*args) — '
foo(**kwargs) — '
foo(*args, **kwargs) — (
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palkan_tula
palkan
foo(*args) — '
foo(**kwargs) — '
foo(*args, **kwargs) — (
def foo in (if | unless) — (
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palkan_tula
palkan
foo(*args) — '
foo(**kwargs) — '
foo(*args, **kwargs) — (
def foo in (if | unless) — (
prepend/class_eval/etc. — '
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palkan_tula
palkan
How can we
implement this?
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ͲͷΑ͏ʹ࣮͢Εྑ͍͔ʁ
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palkan_tula
palkan
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beach(Temperature) ->
case Temperature of
{celsius, N} when N >= 20, N =< 45 ->
'favorable';
{kelvin, N} when N >= 293, N =< 318 ->
'scientifically favorable';
{fahrenheit, N} when N >= 68, N =< 113 ->
'favorable in the US';
_ ->
'avoid beach'
end.
beach({celsius, N}) when N >= 20, N =< 45 ->
'favorable';
beach({kelvin, N}) when N >= 293, N =< 318 ->
'scientifically favorable';
beach({fahrenheit, N}) when N >= 68, N =< 113 ->
'favorable in the US';
beach(_) ->
'avoid beach'.
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palkan_tula
palkan
ಉ͡όΠτίʔυ
Same byte code
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beach(Temperature) ->
case Temperature of
{celsius, N} when N >= 20, N =< 45 ->
'favorable';
{kelvin, N} when N >= 293, N =< 318 ->
'scientifically favorable';
{fahrenheit, N} when N >= 68, N =< 113 ->
'favorable in the US';
_ ->
'avoid beach'
end.
beach({celsius, N}) when N >= 20, N =< 45 ->
'favorable';
beach({kelvin, N}) when N >= 293, N =< 318 ->
'scientifically favorable';
beach({fahrenheit, N}) when N >= 68, N =< 113 ->
'favorable in the US';
beach(_) ->
'avoid beach'.
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palkan_tula
palkan
SyntaxError
Use cases
Implementation
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࣮
Ϣʔεέʔε
→ parser
def ... in → ❤
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palkan_tula
palkan
4
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palkan_tula
palkan
def initialize(@a, @b)
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palkan_tula
palkan
def initialize(@a, @b)
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palkan_tula
palkan
CoffeeScript:
define_method(:initialize) {|@a, @b|}
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def initialize(@a, @b)
initialize(@a, @b) ->
def initialize(@name : String)
Crystal:
Ruby <1.9:
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palkan_tula
palkan
SyntaxError
Use cases
Implementation
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࣮
Ϣʔεέʔε
→ parser, VM?
def initialize(@a) → ❤
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palkan_tula
palkan
Anonymous Struct
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palkan_tula
palkan
Anonymous Struct
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palkan_tula
palkan
ෆม
Zig:
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var pt: Point = .{
.x = 3,
.y = 4,
};
#{ x: 3, y: 4 }
JavaScript (proposal):
Anonymous Struct
Immutable
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palkan_tula
palkan
.{x: 3, y: 4}
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palkan_tula
palkan
SyntaxError
Use cases
Implementation
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࣮
Ϣʔεέʔε
→ parser, stdlib
.{x: 3, y: 4} → ❤
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palkan
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palkan_tula
palkan
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palkan_tula
palkan
|>
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palkan_tula
palkan
॓
|>
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) Your homework
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palkan_tula
palkan
"https://api.github.com/repos/ruby/ruby"
.then { URI.parse(it) }
.then { Net::HTTP.get(it) }
.then { JSON.parse(it).fetch("stargazers_count") }
.then { "Ruby has #{it} stars" }
.then { Kernel.puts(it) }
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palkan_tula
palkan
"https://api.github.com/repos/ruby/ruby"
|> URI.parse
|> Net::HTTP.get
|> JSON.parse(it).fetch("stargazers_count")
|> "Ruby has #{it} stars"
|> Kernel.puts
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palkan_tula
palkan
Try using proposed syntax in your code
Share you examples
Report confusions and edge cases
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͜ͷจ๏ΛࣗͷίʔυͰࢼͯ͠ΈΔ
ॻ͍ͨίʔυΛڞ༗͢Δ
͏·͍͔͘ͳ͍ྫΤοδέʔεΛใࠂ
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palkan_tula
palkan
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bit.ly/ruby-mixology
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Thank You
Slides: evilmartians.com/events
Twitter: @palkan_tula, @evilmartians
͋Γ͕ͱ͏