18 lines
458 B
Text
18 lines
458 B
Text
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s@(Sequence traits) forwardDifference
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[
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s allButFirst with: s allButLast collect: #- `er
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].
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s@(Sequence traits) forwardDifference
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"Without creating two intermediate throwaway Sequences."
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[
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result ::= s allButFirst.
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result doWithIndex: [| :nextValue :index | result at: index infect: [| :oldValue | oldValue - (s at: index)].
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result
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].
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s@(Sequence traits) forwardDifference: n
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[
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(0 below: n) inject: s into: [| :seq :_ | seq forwardDifference]
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].
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