22 lines
455 B
Factor
22 lines
455 B
Factor
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! (c)2009 Joe Groff bsd license
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USING: kernel math tools.test variants ;
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IN: variants.tests
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VARIANT: list
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nil
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cons: { { first object } { rest list } }
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;
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[ t ] [ nil list? ] unit-test
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[ t ] [ 1 nil <cons> list? ] unit-test
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[ f ] [ 1 list? ] unit-test
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: list-length ( list -- length )
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{
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{ nil [ 0 ] }
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{ cons [ nip list-length 1 + ] }
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} match ;
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[ 4 ]
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[ 5 6 7 8 nil <cons> <cons> <cons> <cons> list-length ] unit-test
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