351e82735b
Renamed `convert' to `pict-convert', etc., to avoid confusion with `file/convert' bindings. Moved out of `slideshow/pict' to `slideshow/pict-convert', because most `slideshow/pict' clients do not need it.
20 lines
667 B
Racket
20 lines
667 B
Racket
#lang racket/base
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(provide prop:pict-convertible prop:pict-convertible? pict-convertible? pict-convert)
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(define-values (prop:pict-convertible -pict-convertible? pict-convertible-ref)
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(make-struct-type-property 'pict-convertible))
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(define-values (prop:pict-convertible? pict-convertible?? pict-convertible?-ref)
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(make-struct-type-property 'pict-convertible?))
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(define (pict-convertible? x)
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(and (-pict-convertible? x)
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(if (pict-convertible?? x)
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((pict-convertible?-ref x) x)
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#t)))
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(define (pict-convert v)
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(unless (pict-convertible? v)
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(raise-type-error 'pict-convert "pict-convertible" v))
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((pict-convertible-ref v) v))
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