Taipei.rb 寫一個送禮自用兩相宜的 Compiler

Transcript

1. 用 Ruby 寫一個送禮自用
   兩相宜的 Compiler
   

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2. 襟
   儘
   䓛⛳
   @elct9620
   WEB DEVELOPER
   GAME DEVELOPER
   

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5. #I_feel_border
   ⼤大家都在寫 Compier 作業
   

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6. C4 不夠⽤用就⽤用 C5 啊！
   https://github.com/elct9620/5compiler
   Demo First Talk
   

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7. Lexer
   Tokenizer
   Parser
   Source Code
   AST
   

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8. 簡單說就是照規則把字串串切開來來
   Lexer
   

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9. Lexer.new("count = 1 if reset")
   # ['count', '=', '1', 'if', 'reset']
   Lexer
   

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10. class Lexer < Array
    KEYWORDS =
    %w[if else end puts].freeze
    KEYWORD_RULE =
    /(?#{KEYWORDS.join('|')})/
    end
    Lexer
    

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11. RULE = Regexp.union(
    LINEFEED_RULE,
    SYMBOL_RULE,
    KEYWORD_RULE,
    STRING_RULE,
    NUMBER_RULE,
    WORD_RULE
    )
    Lexer
    

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12. script.scan(RULE).flatten.compact
    # ['count', '=', '1', 'if', 'reset']
    Lexer
    

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13. 把 Lexer 切好的⽂文字片段做簡單的分類
    Tokenizer
    

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14. Tokeinzer.new(['if', 'reset'])
    # [
    # # @value="if">
    # # @value="reset">
    # ]
    Tokenizer
    

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15. MATCH_RULES.each do |type, rule|
    if word.match?(rule)
    return Token.new(type, word)
    end
    end
    Token.new(:literal, word)
    Tokenizer
    

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16. class Token
    # ...
    def symbol?
    type == :symbol
    end
    # ...
    end
    Tokenizer
    

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17. 依照 Token 的狀狀況轉換成⽤用樹狀狀的⽅方式表⽰示程式運作
    Parser
    

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18. IF
    TRUE FALSE
    BLOCK BLOCK
    

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19. class Parser
    def parse
    tokens = @tokenizer.to_enum
    @context =
    Node::Context.new(tokens)
    @ast = context.ast
    end
    end
    Parser
    

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20. loop do
    break if t.peek.else? || #...
    #…
    if t.peek.fn?
    next @ast << Node::Function.new(t)
    end
    #...
    end
    Parser
    

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21. Context
    Parser
    Function
    Enter
    Context State
    Exit State
    Next token is ‘else’
    Enter
    Function State
    Exit State
    Next token is ‘end’
    

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22. 基於 Parser ⽣生成的 Abstract Syntax Tree 執⾏行行程式
    Virtual Machine
    

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23. 將 AST 轉換為機器碼或者 VM 可以直接讀取的規格
    Bytecode
    

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24. 借⽤用 Ruby VM 直接執⾏行行 `Kernel.send(‘puts’, ‘Hello World’)`
    5Compiler’s VM
    

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25. 在 Router 中可以⽤用來來判斷⽬目前請求的網址對應的 Controller
    Rails’s AST
    

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26. 在 ActiveRecord (Arel) 可以⽤用來來組成 SQL 語法
    Rails’s AST
    

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27. ⽤用來來動態執⾏行行 ActiveRecord 相關的動作 Ex. JSON Query, Update …
    Tamashii::TLang’s AST
    

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28. 很可惜困難的是 VM 怎麼動起來來喔⋯⋯
    聽起來來好像很簡單，對吧？
    

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