53 lines
1000 B
Scheme
53 lines
1000 B
Scheme
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; Copyright (c) 1993, 1994 Richard Kelsey and Jonathan Rees. See file COPYING.
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; ((method () 1)) => 1
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; ((method () 1) 2) => error
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; ((method (x) 1) 2) => 1
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; ((method ((x <symbol>)) 1) 2) => error
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; ((method ((x <symbol>)) 1) 'foo) => 1
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; ((method ((x <symbol>)) (next-method)) 'foo) => error
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(define-generic-function elt ((s <sequence>)))
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(define-method elt ((x <vector>) y)
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(vector-ref x y))
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; (elt '#(a b c) 1) => b
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(define-method elt ((x <string>) y)
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(string-ref x y))
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(define-method elt ((x <list>) y)
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(list-ref x y))
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; Setters
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(define-generic-function (setter elt)
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(thing index new-value))
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(define-method (setter elt) ((x <vector>) i z)
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(vector-set! x i z))
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; (let ((v (vector 1 2 3))) (set (elt v 1) 'foo) v) => '#(1 foo 3)
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; Classes
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(define-class <mumble> () a b)
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; (a (make <mumble>)) => '*uninitialized*
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; (let ((m (make <mumble>))) (set (a m) 'foo) (a m)) => 'foo
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(define-method initialize ((m <mumble>) z)
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(set (a m) z))
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; (a (make <mumble> 3)) => 3
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