36 lines
959 B
Text
36 lines
959 B
Text
inductive Term : Type
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| const : Nat -> Term
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| app : List Term -> Term
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namespace Term
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instance : Inhabited Term := ⟨Term.const 0⟩
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partial def hasToString : Term -> String | const n => "CONST(" ++ toString n ++ ")" | app ts => "APP"
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instance : HasToString Term := ⟨hasToString⟩
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end Term
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open Term
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structure MyState : Type := (ts : List Term)
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def emit (t : Term) : StateM MyState Unit := modify (λ ms => ⟨t::ms.ts⟩)
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partial def foo : MyState -> Term -> Term -> List Term
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| ms₀, t, u =>
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let stateT : StateM MyState Unit := do {
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match t with
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| const _ => pure ()
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| app _ => emit (const 1) *> pure () ;
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match t, u with
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| app _, app _ => emit (app []) *> pure ()
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| _, _ => pure () ;
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match t, u with
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| app _, app _ => emit (app []) *> pure ()
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| _, _ => emit (const 2) *> pure ()
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} ;
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(stateT.run ⟨[]⟩).2.ts.reverse
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def main : IO Unit := IO.println $ foo ⟨[]⟩ (app []) (app [])
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