TypeScript で型検査器を作る / Implementing a type checker with TypeScript

Transcript

1. 5ZQF4DSJQUͰܕݕࠪثΛ࡞Δ
   ܕษڧձ
   

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2. ܕݕࠪث
   w ͋Δܭࢉମܥʹ͓͚Δ߲ͷܕΛಋग़͢Δ
   w ܕ෇͚نଇʹ౰ͯ͸·Βͳ͍߲͕ଘࡏ͢Δ࣌͸

   ΤϥʔΛ౤͛Δ
   

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3. +BWB4DSJQUͷܕݕࠪثΛ
   ࡞ͬͯΈΔ
   w ඞཁʹഭΒΕͨͷͰʜʜ
   w ߏจ໦͸&TQSJNBͱ͔Λ࢖ͬͯಘΔ͜ͱ͕Ͱ͖Δ
   w 5ZQF4DSJQUͷܕ৘ใΛదٓ༗ޮ׆༻͢Δ
   w ؆୯ͷͨΊʹɺ߲͸෭࡞༻Λ࣋ͨͳ͍΋ͷͱ͢Δ
   

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4. "45&YQMPSFS
   IUUQTBTUFYQMPSFSOFU
   

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5. ܕ෇͚نଇͷྫ
   • true: boolean
   • t: string ∧ u: U → (t + u): string
   • t: T ∧ u: T → (t === u): boolean
   • t: { u: U } → t.u: U
   ˢΛͦͷ··࣮૷͢Ε͹0,
   

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6. είʔϓ
   w ݱࡏݕ͍ࠪͯ͠Δ߲Ͱར༻Մೳͳม਺ͷҰཡΛ

   ͓࣋ͬͯ͘ඞཁ͕͋ΔͷͰɺ
   function typeOf(ast: ESTree.Node, scope: Var[]): Type
   Έ͍ͨͳײ͡ʹͳΔ
   

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7. ΤϥʔΛूΊΔ
   w ܕ෇͚نଇʹ౰ͯ͸·Βͳ͍࣌ʹΤϥʔΛ౤͛Δ

   ͷͰ͸ͳ͘ɺจ຺ʹΤϥʔΛ௥Ճ͢Δ
   w ϝοηʔδ΍ιʔείʔυ্ͷ৔ॴΛ෇༩͢Δͱศར

   ΤσΟλʔͱ͔Ͱ੺ઢΛҾ͚Δ
   
   

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8. શମ૾
   function typeOf(ast: ESTree.Node, scope: Var[]) {
   switch (ast.type) {
   case ‘BinaryOperator’:
   // …
   case ‘…’:
   default:
   this.errors.push({
   message: ‘…’, start: …, end: …
   })
   }
   }
   

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