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#lang racket/base
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(require racket/dict "number.rkt" "helper.rkt" "generic.rkt")
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(provide (all-defined-out))
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(define (length-resolvable? x)
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(or (not x) (symbol? x) (xenomorphic? x) (procedure? x) (exact-nonnegative-integer? x)))
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(define (resolve-length x port [parent #f])
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(cond
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[(not x) #f]
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[(exact-nonnegative-integer? x) x]
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[(procedure? x) (x parent)]
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[(and parent (symbol? x)) (dict-ref parent x)]
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[(and port (x:int? x)) (decode x port)]
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[else (raise-argument-error 'resolve-length "fixed-size argument" x)]))
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