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Ruby Conf Taiwan 2023
John Lin (@johnlinvc)
Unearth Ruby builtin
Gems
發掘 Ruby 的內建
Gems
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Ruby Conf Taiwan 2023
About ME 關於我
• John Lin
• @johnlinvc
• Principle Architect @ West Pharma
西
式亞洲
• https://johnlin.vc
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Ruby Conf Taiwan 2023
Agenda
大
綱
• What is builtin gem?
什麼是內建 gems
• Introduce some useful / interesting builtin gems.
介紹有
用
/有趣的內建 gems。
• Slide 投影片 : https://johnlin.vc/ruby-conf-tw-2023/
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Ruby Conf Taiwan 2023
What is builtin Gem? 什麼是內建 Gems?
• Gems that come with the default ruby installation.
安裝 Ruby 時就會預設安裝的 Gems。
• Part of the Standard library.
Standard library 的
一
部分。
• To provide extended features.
提供額外功能。
• 3 types of Standard libraries. 有 3 種 Standard libraries
Default Library, Default Gem & Bundled Gem.
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Ruby Conf Taiwan 2023
Default Library
• Ruby version/implementation related library. Will NOT become Gems.
Ruby 版本/實作相關的 library。不會變成 Gems。
• Example 範例
• mkmf: Generate Make
fi
le for C extensions (only in MRI)
幫 C extension 產
生
Make
fi
le （只有 MRI 有)
• rbcon
fi
g: List system info like size of Long. (JRuby use FFI) (MRI use c extension)
列舉系統資訊，像是 long 的
大
小
。 (JRuby
用
FFI) (MRI
用
c extension)
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Ruby Conf Taiwan 2023
Default gem
• Installed by default. 預設就會安裝。
• Can be upgraded. 可以升級。
• Can NOT be deleted. 不能被刪除。
• Maintained by ruby core. 由 Ruby core 維護。
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Ruby Conf Taiwan 2023
Bundled gem
• Starting from 2.2.0 https://bugs.ruby-lang.org/issues/9852
2.2.0 開始
• Installed by default. 預設就會安裝
• Can be upgraded & uninstalled. 可以升級或刪除。
• Need to be added to Gem
fi
le when using Bundler。
用
Bundler 的時候需要加進 Gem
fi
le 裏。
• Not maintained by Ruby core. 不由 Ruby core 維護。
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Ruby Conf Taiwan 2023
Why default/bundled gems?
• To provide extra features. 提供額外功能。
• Unbind the development of these gem from the interpreter itself.
讓這些 Gem 可以獨立於直譯器外開發。
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Ruby Conf Taiwan 2023
Default vs bundled gems
• Bundled gems can be uninstalled.
Bundled gems 可以被反安裝。
• Bundled gems need to be added to Gem
fi
le when using Bundler。
bundled gems 在
用
Bundler 的時候需要加進 Gem
fi
le 裏。
• There's an e
ff
ort to promote default gem into bundled gem by @hsbt.
@hsbt 正在努
力
的把 default gem 升格為 bundled gem。
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Ruby Conf Taiwan 2023
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Ruby Conf Taiwan 2023
Find out builtin gems
• https://stdgems.org/
• Or Use the source.
或是看原始碼。
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Builtin gems by buried level 埋藏深度
• Surface 地表
• Crust 地殼
• Mantle 地函
• Core 地核
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Surface 地表
• Too famous to be in this talk. 太有名了，就不講了。
• irb
• rake
• rbs
• minitest
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Crust 地殼
A lot of people are using them.
滿多
人
在
用
的。
• Base64
• Set
• OpenStruct
• Secure Random
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base64
• Convert to & from base64 encoding.
64進位編碼轉換器。
• Maintainer: Yusuke Endoh (@mametter). World No.1 IOCCC player.
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base64
• base64 encoding is not encryption, more
like binary or hexadecimal .
base64 不是加密，比較像是
二
進位或
十
六進
位。
• Don't use it for encryption / hashing !
不要
用
它來加密或是計算雜湊！
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base64
• encode64: output splitted with newline if too
long, have an ending newline
編碼的輸出會
自
動換
行
。結尾也有換
行
。
• decode64, ignore any none base64 chars &
newline.
會忽略輸入中的不合格字元和換
行
。
require 'base64' # => true
binary = "\x0a\x1b\x2c\x3d\x4e\x5f"
# => "\n" + "\e,=N_"
b64 = Base64.encode64(binary) # =>
"ChssPU5f\n"
Base64.decode64(b64)==binary # =>
true
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Ruby Conf Taiwan 2023
base64
• Very dense implementation.
實作超級簡潔。
• Likely because it's Mr. Endo?
大
概因為是 Endo 寫的？
def encode64(bin)
[bin].pack("m")
end
def decode64(str)
str.unpack1("m")
end
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Ruby Conf Taiwan 2023
base64
• strict_encode64, output without any
newline.
輸出不會有任何換
行
。
• strict_decode64, raise error when there's
any non base64 chars
當有任何不合格字元時，會 raise error。
Base64.encode64("a"*50) # =>
"YWFhYWFhYWFhYWFhYWFhYWFhYWFhYWFhYW
FhYWFhYWFhYWFhYWFhYWFhYWFh\n" +
"YWFhYWE=\n"
Base64.strict_encode64("a"*50) # =>
"YWFhYWFhYWFhYWFhYWFhYWFhYWFhYWFhYW
FhYWFhYWFhYWFhYWFhYWFhYWFhYWFhYWE="
Base64.strict_decode64("aaaa\n") #
=> :29:in `unpack1':
invalid base64 (ArgumentError)
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base64
• urlsafe_encode64, same as strict, but use -
instead of +, _ instead of / to avoid url
encoding issue
和strict
一
樣，但是
用
- 取代 +，
用
_ 取代 /
來避免 URL 編碼問題。
• urlsafe_encode64, decode data encoded by
urlsafe_encode64
用
來解上
面
的輸出。
plus_slash = "+/+/" # => "+/+/"
b64_plus_slash =
Base64.decode64(plus_slash) # =>
"\xFB\xFF\xBF"
Base64.encode64(b64_plus_slash) #
=> "+/+/\n"
Base64.urlsafe_encode64(b64_plus_sl
ash) # => "-_-_"
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Ruby Conf Taiwan 2023
Set
• A data stucture that contains only uniq values.
只包含獨特值的資料結構。
• Useful when doing interview questions.
面
試的時候很有
用
。
• Maintainer: Akinori MUSHA (@knu)
•
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Set
• Set#add to add new value.
加入新的值
• Set#delete to delete value.
刪除
一
個值
• Set#include? to check if values inside
檢查有沒有某個值
set = Set.new # => #
set.add("rubyconf") # => #
set.add("tw") # => #
set.include?("tw") # => true
set.delete("tw") # => #
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Ruby Conf Taiwan 2023
Set
• Actually implemented with Hash.
實際上是
用
Hash 實作的。
• store ture as the value.
Hash 存的值是 true。
def initialize(enum = nil,
&block)
@hash ||= Hash.new(false)
...
end
def add(o)
@hash[o] = true
self
end
def include?(o)
@hash[o]
end
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Ruby Conf Taiwan 2023
Set
• Set.add? returns self if add successfully.
可以邊加值邊檢查裡
面
現在是不是已經有
了。
•
set = Set.new # => #
set.add?("tw") # => #
set.add?("tw") # => nil
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Ruby Conf Taiwan 2023
Set
• Set#intersection, & :
fi
nd intersection.
找交集。
• Set#union, | :
fi
nd union.
找聯集。
• Set#di
ff
erence, - :
fi
nd di
ff
erence.
找差集。
japan = Set.new(%w{japan rubykaigi
ruby}) # => #
tw = Set.new(%w{tw rubyconfg ruby})
# => #
japan & tw # => #
japan | tw # => #
japan - tw # => #
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OpenStruct
• A Struct with dynamic member, allow using dot to access member.
有動態元素的 struct，可以
用
"." 來存取。
• Maintainer: Marc-André Lafortune(@malafortune)
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OpenStruct
• Allow direct access with dot .
可以
用
"." 來存取。
• Can be accessed with [] as well.
也可以
用
[] 來存取。
• Don't work if the key have weird stu
ff
.
不過如果 key 太奇怪就會壞掉。
require 'ostruct' # => true
person = OpenStruct.new # =>
#
person.name = "John Smith" # =>
"John Smith"
person.name # => "John Smith"
person.address # => nil
person[:name] # => "John Smith"
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secure random
• Generate random number using CPRNG(https://en.wikipedia.org/wiki/
Cryptographically_secure_pseudorandom_number_generator)
產
生
密碼學安全的亂數。
• Maintainer: Tanaka Akira (@tanaka_akr)
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Secure Random vs Random
• Random#rand :
• Use Mersenne Twister, need a seed.
用
Mersenne Twister，需要 seed。
• Can be predicted after 624 calls.
觀察輸出 624 次後就可以預測下
一
個值。
• Secure Random
• Use /dev/urandom, Win32 or openssl
使
用
/dev/urandom, Win32 or openssl
• Hard to predict next output
很難預測下
一
個值。
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Secure random
• Provide some wrapper around the
generated random number
亂數的輸出有
一
些
方
便使
用
的格式。
• rand to return a value between 0 and 1
回傳 0 到 1 之間的值。
• bytes to return some bytes
回傳
一
些 byte。
• uuid, alphanumeric, base64.
require 'securerandom' # => true
SecureRandom.rand # =>
0.46760427030684526
SecureRandom.bytes(8) # => "K+
\xE1\xA2Q\xCFm\xBD"
SecureRandom.uuid # =>
"73f0a178-3745-48eb-8a30-0f7364760b
47"
SecureRandom.alphanumeric # =>
"IRCQihGOALKHhuf7"
SecureRandom.base64 # =>
"cnBxZuU93ZqbRqolOYNmxA=="
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Mantle 地函
Useful in some situation. less people know about them.
有的時候有
用
，比較少
人
知道。
• tsort
• FileUtils
• IPAddr
• abbrev
• un
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tsort
• Topological sort for graph.
用
來找 graph 裡
面
的拓墣排序。
• Topological sort is the order of nodes by it's dependency.
拓墣排序是節點
用
相依性排列後的順序。
• Maintainer: Akira Tanaka (@tanaka_akr)
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tsort
• It's a mixin module, require your class to
provide 2 methods
是
一
個 mixin module。需要
自己
實作兩個
method。
• tsort_each_node to provoide a list of nodes.
提供所有的 node
• tsort_each_child to provide a list of children
for a speci
fi
c node.
提供某
一
個 node 的所有 child。
• Call tsort to get reversed topological sort
order.
回傳反轉過的拓墣排序。
require 'tsort' # => true
class Hash
include TSort
alias tsort_each_node each_key
def tsort_each_child(node,
&block)
fetch(node).each(&block)
end
end # => :tsort_each_child
{1=>[2, 3], 2=>[3], 3=>[],
4=>[]}.tsort # => [3, 2, 1, 4]
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tsort
• By name, it's doing topological sort. But actually it's running a Strongly connected
components algorithm, Tarjan's strongly connected components algorithm.
看起來好像是跑 topological sort 。但實際上是跑 Tarjan's 演算法來找 Strongly connected
components 。
• There's a Bug section about naming in README.
說明裡有
一
個 Bug 段落來講命名。
• Tarjan's algorithm also outputs a
reversed topological sort
剛好會輸出反轉過的拓墣排序
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tsort
• Call strongly_connected_components to get
Strongly connected components .
回傳 Strongly connected components。
require 'tsort' # => true
class Hash
include TSort
alias tsort_each_node each_key
def tsort_each_child(node,
&block)
fetch(node).each(&block)
end
end # => :tsort_each_child
{1=>[2], 2=>[3, 4], 3=>[2],
4=>[]}.strongly_connected_component
s # => [[4], [2, 3], [1]]
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Fileutils
• Handle common
fi
le operations across platforms.
可以跨平台處理檔案。
• Maintainer: Minero Aoki (@mineroaoki).
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Fileutils
• FileUitls.rm_rf to delete folder and all it's
contents.
刪除
目
錄和之下的所有檔案。
• cp_r to copy folder and all it's contents.
複製
目
錄和之下的所有檔案。
• mkdir_p to create folder and all it's parent if
not exists.
創造
目
錄，包含所有的
母目
錄。
• touch to update modify time
更新修改時間。
require 'fileutils' # => true
FileUtils.mkdir_p("test/
file_utils") # => ["test/
file_utils"]
FileUtils.touch("test/
file_utils/.keep") # => ["test/
file_utils/.keep"]
FileUtils.cp_r("test/file_utils",
"test/copy") # => nil
FileUtils.rm_rf("test") # =>
["test"]
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ipaddr
• Operations on IP address .
操作 IP 位置。
• Maintainers: Akinori MUSHA (@knu) & Hajimu UMEMOTO (@h_ume)
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ipaddr
• & to
fi
nd bitwise AND, NOT intersection
對位元作AND，不是交集。
• | to
fi
nd bitwise OR, NOT union
對位元作AND，不是聯集。
• include? to check if IP is in a CIDR
檢查IP是不是在區塊內。
require 'ipaddr' # => true
addr1 = IPAddr.new("10.1.10.1/24")
# => #
addr2 = IPAddr.new("10.1.20.1/24")
# => #
addr1 | addr2 # => #
addr1 & addr2 # => #
addr1.include?
(IPAddr.new("10.1.10.20")) # =>
true
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ipaddr
• private? to check if it's a private IP.
檢查是否是私有網路IP
• loopback? to check if it's a loopback IP.
檢查是否是環回 IP
• to_range to cast it to a range for iteration.
可以轉換成 range。
ip172 = IPAddr.new("172.25.3.4") # =>
#
ip172.private? # => true
local = IPAddr.new("127.0.0.4") # =>
#
local.loopback? # => true
block192 = IPAddr.new("192.168.3.32/28")
# => #
block192.to_range # => #
..
#
block192.to_range.count # => 16
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abbrev
• Find all the possible uniq abbreviation for a set of string.
幫
一
組字串找出所有可能的縮寫。
• Useful for CLI arguments, for example ./my_cmd u can be expanded into ./my_cmd update
using abbrev.
處理命令列參數時很好
用
，./my_cmd update 可以縮寫成 ./my_cmd u。
• Maintainer: Akinori MUSHA (@knu)
•
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abbrev
• .abbrev take a array of stings.
輸入是
一
個字串陣列。
• returns a Hash as lookup table.
回傳
一
個Hash 查找表。
• No ambiguous pre
fi
x in the lookup table.
表裡
面
沒有會對到不同字串的 pre
fi
x
Abbrev.abbrev(%w{ install update
upgrade }) # => {"install"=>"install",
"instal"=>"install",
"insta"=>"install",
"inst"=>"install",
"ins"=>"install",
"in"=>"install",
"i"=>"install",
"update"=>"update",
"updat"=>"update",
"upda"=>"update",
"upd"=>"update",
"upgrade"=>"upgrade",
"upgrad"=>"upgrade",
"upgra"=>"upgrade",
"upgr"=>"upgrade",
"upg"=>"upgrade"}
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Ruby Conf Taiwan 2023
un
• Useful to do things as cli one liner.
提供
一
些命令列的指令。
• Useful in Make
fi
le for cross platform。
寫跨平台 Make
fi
le 的時候很好
用
。
• When combined with the require -r
fl
ag, looks like -run
當和 require
用
的 -r 參數放在
一
起的時候。看起來像 -run。
• Maintainer: WATANABE Hirofumi
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un
• ruby -run -e cp -- [OPTION] SOURCE DEST to copy
fi
les
複製檔案
• ruby -run -e mv -- [OPTION] SOURCE DEST to move
fi
le/folder
移動檔案
• ruby -run -e httpd -- [OPTION] [DocumentRoot] start a http server at DocumentRoot, but
need to install webrick after Ruby 3.0.0. Useful to transfer
fi
le in local network.
開
一
個 http server。不過在 Ruby 3.0.0 之後需要額外裝 webrick。
用
來在區網傳檔案很好
用
。
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Core 地核
Most people don't know Ruby have this as builtin.
大
部分
人
不知道 Ruby 有內建
Or don't know we can use it directly.
或是不知道可以直接拿來
用
。
• prime
• Forwardable
• Delegate
• Singleton
• did_you_mean
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Prime
• Bundled gem
• Generate prime number, checks prime number, prime factorization.
產
生
質數，檢查質數，質因數分解。
• Maintainer: Marc-Andre Lafortune(@malafortune)
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Prime
• Use Miller–Rabin primality test to check
prime,
用
Miller-Rabin 來檢查是否是質數。
• Become very slow after reaching limit of
Miller–Rabin.
3_317_044_064_679_887_385_961_981
超過 Miller-Rabin 的極限後就會變慢。
•
require 'prime' # => true
Prime.prime?(7) # => true
8.prime? # => false
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Prime
• Use Sieve of Eratosthenes to generate
Primes
用
埃拉托斯特尼篩法 來產
生
質數。
Prime.take(4) # => [2, 3, 5, 7]
Prime.each(7).to_a # => [2, 3, 5,
7]
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Prime
• Use Wheel factorization for prime division.
用車
輪分解來產
生
質因數分解
用
的因數。
Prime.prime_division(8959) # =>
[[17, 2], [31, 1]]
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Forwardable
• Forward speci
fi
c method calls to another object.
轉發特定 method 給其他物件。
• Maintainer: Keiju Ishitsuka, Ruby' god father. Who coined the name Ruby with Matz
Ruby 的教
父
，和 Matz
一
起討論了 Ruby 這個名字。
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Forwardable
• def_delegator , delegate to another object
with di
ff
erent name
轉發呼叫給另
一
個物件的特定 method。
class RecordCollection
attr_accessor :records
extend Forwardable
def_delegator :@records, :
[], :record_number
end # => :record_number
r = RecordCollection.new # =>
#
r.records = [4,5,6] # => [4, 5, 6]
r.record_number(0) # => 4
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Forwardable
• def_delegators, delegate methods to
another object.
轉發呼叫給其他物件。
class RecordCollection
def_delegators :@records, :size,
:<<, :map
end # => [:size, :<<, :map]
r = RecordCollection.new # =>
#
r.records = [1,2,3] # => [1, 2, 3]
r.size # => 3
r << 4 # => [1, 2, 3, 4]
r.map { |x| x * 2 } # => [2, 4, 6,
8]
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Delegate
• Delegate all unde
fi
ned methods.
轉發所有未定義的 method。
• Maintainer: Yukihiro Matsumoto (@yukihiro_matz) , Ruby's Father.
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Delegate
• DelegateClass: create a super class that
wraps the Delegated class.
創造
一
個新的 class ，把轉發的
目
標包住。
• Main interface
主要的
用
法。
class TimeWithAgo <
DelegateClass(Time)
def initialize(arg)
@t = Time.new(arg)
super(@t)
end
def years_ago = Time.now.year -
year
end # => :years_ago
t = TimeWithAgo.new("1993-02-24
UTC") # => 1993-02-24 00:00:00 UTC
t.year # => 1993
t.years_ago # => 30
~
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Delegate
• Simple delegator , forward all unde
fi
ned
methods to the the target object.
轉發所有未定義的 method 給
目
標物件。
class TimeDecorator <
SimpleDelegator
def years_ago = Time.now.year -
year
end # => :years_ago
t =
TimeDecorator.new(Time.new("1993-02
-24 UTC")) # => 1993-02-24 00:00:00
UTC
t.year # => 1993
t.years_ago # => 30
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Delegate vs inheritance
• Delegate only delegate public methods, protecting private methods from send calls.
Delegate 只會轉發給 public method，可以
用
來讓 send 呼叫不到 private method。
• "Has a" vs "Is a"
有
一
個 vs 是
一
個。
• Delegate can be recon
fi
gured during runtime easily.
Delegate 可以在執
行
期動態修改
目
標。
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Ruby Conf Taiwan 2023
Singleton
• Provide Singleton pattern. 提供單例模式
支
援。
• Maintainer: Yukihiro Matsumoto (@yukihiro_matz) , Ruby's Father.
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Ruby Conf Taiwan 2023
Singleton
• #instance returns the singleton instance.
回傳單例實體。
• .new is marked private.
.new 變成 private
• Easier to understand than class instance
variable @@var.
比起
用
class instance varible 容易理解。
• Thread safe
執
行
序安全。
class BDFL
include Singleton
def name = "Matz"
end # => :name
BDFL.instance.name # => "Matz"
BDFL.new # =>
(...:in `': private method
`new' called for class BDFL
(NoMethodError)
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Ruby Conf Taiwan 2023
Did you Mean
• Help user
fi
nd typos in their code.
幫助使
用
者尋找錯字。
• Maintainer: Yuki Nishijima (@yuki24)
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Ruby Conf Taiwan 2023
Did you Mean
• Generates suggestion in error messages.
在錯誤訊息中產
生
建議。
• Works for methods & constants etc.
對 method 和 constant 名都有效。
3.3.0-preview3 :001 > evel(1)
(irb):1:in `': undefined method
`evel' for main (NoMethodError)
Did you mean? eval
3.3.0-preview3 :003 > Irb
(irb):3:in `': uninitialized
constant Irb (NameError)
Did you mean? IRB
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Ruby Conf Taiwan 2023
Did you Mean
• You can call it's word comparing methods
directly.
可以直接呼叫他的字串比對 method。
• Levenshtein distance, also known as edit
distance.
萊
文
斯坦距離 ，
又
叫編輯距離。
• Jaro–Winkler distance, normalized similarity.
Jaro–Winkler 距離，正規化的相似度。
DidYouMean::Levenshtein.distance("r
ubyconf tw", "rubykaigi") # => 7
DidYouMean::Jaro.distance("rubyconf
tw", "rubykaigi") # =>
0.6026936026936026
DidYouMean::JaroWinkler.distance("r
ubyconf tw", "rubykaigi") # =>
0.6026936026936026
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Ruby Conf Taiwan 2023
Customize Did you Mean to find path error
class EnoentChecker
def initialize(exception)
@rel_path = exception.message.split("-")[1].strip
@path = File.expand_path(@rel_path, File.dirname(__FILE__))
end
def dictionary = Dir.foreach(File.dirname(@path)).to_a
def corrections =
DidYouMean::SpellChecker.new(dictionary:).correct(@rel_path).uniq
end # => :corrections
DidYouMean.correct_error Errno::ENOENT, EnoentChecker # => Errno::ENOENT
File.read("hallo.txt") # =>
didyoumean.rb:14:in `read': No such file or directory @ rb_sysopen -
hallo.txt (Errno::ENOENT)
Did you mean? hello.txt
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Ruby Conf Taiwan 2023
Takeaway 結論
• Ruby is battery-included. Tons of good stu
ff
s in standard libraries.
Ruby 內建很多功能。標準函式庫裡有很多好東
西
。
• There's an ongoing e
ff
ort of promoting standard libraries to bundled gems.
正在努
力
把標準函式庫升級成 bundled gems。
• https://stdgems.org/ have a list of standard libraries.
有標準函式庫的清單。
• Next time you can check the Standard library before searching for 3rd party gems.
下
一
次在
用
第三
方
Gem 之前，可以先看看標準函式庫有沒有。
•
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Q&A
X: @johnlinvc
Slide : https://johnlin.vc/rubyconftw2023