14 lines
337 B
Racket
14 lines
337 B
Racket
#lang typed/racket
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(require "../traversal.hl.rkt")
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(define-fold f₁ t₁ Null String)
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;(define-fold f₂ t₂ (Pairof Null Null) String)
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;(define-fold f₃ t₃ String String)
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;(define-fold f₄ t₄ (Pairof Null String) String)
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((f₁ string?
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(λ ([x : String] [acc : Integer])
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(values (string->symbol x) acc)))
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'()
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0) |