18 lines
542 B
Scheme
18 lines
542 B
Scheme
;; Mike Burns 2004
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;; Used for send/suspend/callback.
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(module xexpr-callback mzscheme
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(require (lib "xml.ss" "xml"))
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(provide xexpr/callback?)
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;; Is it a Xexpr, or an Xexpr with procedures?
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(define (xexpr/callback? x)
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(correct-xexpr? x
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(lambda () #t)
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(lambda (exn)
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(if (procedure? (exn:invalid-xexpr-code exn))
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#t
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(begin ((error-display-handler) (exn-message exn) exn)
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#f))))))
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