15 lines
428 B
Racket
15 lines
428 B
Racket
#lang racket/base
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(require lang/private/signature-syntax)
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;; The posn struct for the teaching languages
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(provide struct:posn make-posn posn? posn-x posn-y set-posn-x! set-posn-y!
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(rename-out (posn-signature posn)))
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(struct posn (x y) #:mutable #:transparent)
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;; We define a separate function so tha it has the
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;; name `make-posn':
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(define (make-posn x y) (posn x y))
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(define posn-signature (signature (predicate posn?))) |