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<p><b>Code to reproduce:</b></p>
<p>(1 to: 10) shuffled.</p>
<p><br>
</p>
<p><b>Expected behavior:</b></p>
<p>output matches the condition [output sameElements: (1 to: 10)].</p>
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<p><b>Actual behavior:</b></p>
<p>Error: You cannot store into interval!</p>
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<p><b>Considerations:</b></p>
<p>The same problem also exists for: Symbol, ShortRunArray, and SortedCollection which are not modifiable.</p>
<p>#shuffledBy: performs #shuffleBy: on a copy of the receiver.</p>
<p>We could instead use something like (self asModifiable) to ensure that #swap:with: does not fail.</p>
<p>This could basically be [self as: self species], but unfortunately, this is more than three times slower than #copy.</p>
<p>How would you think about:</p>
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<p>asModifiable</p>
<p> self class = self species</p>
<p> ifTrue: [^ self].</p>
<p> ^ self as: self species</p>
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<p>In general, #swap:with: and so #shuffleBy: are only efficient for Arrays and OrderedCollections, but not for RunArrays or LinkedLists.</p>
<p>Should we maybe just convert the receiver into an array in #shuffledBy:? Is #shuffledBy: required to return an object of self species?</p>
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<p>Best,</p>
<p>Christoph</p>
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