22 lines
567 B
Plaintext
22 lines
567 B
Plaintext
declare
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fun {DropUntil Xs Prefix}
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case Xs of nil then nil
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[] _|Xr then
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if {List.isPrefix Prefix Xs} then Xs
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else {DropUntil Xr Prefix}
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end
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end
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end
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Digits = "1234567890"
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in
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{ForAll
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[{List.take {List.drop Digits 2} 3} = "345"
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{List.drop Digits 2} = "34567890"
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{List.take Digits {Length Digits}-1} = "123456789"
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{List.take {DropUntil Digits "4"} 3} = "456"
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{List.take {DropUntil Digits "56"} 3} = "567"
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{List.take {DropUntil Digits "31"} 3} = ""
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]
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System.showInfo}
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