Smalltalk example to shuffle an OrderedCollection with a Seed

[Cristian Vogel]

I found out the built in Kyma ‘anOrderedCollection shuffle’  was not seedable, so I came up with this block closure that does it.

 

| panPositions shuffler |

panPositions := ?panPositions asOrderedCollection.

shuffler := [:coll |
|n k r|
n := coll size.
r := Random new seededWith: ?seed.
[ n > 1 ] whileTrue: [
k := r nextIntegerBetween: 1 and: n.
coll swap: n with: k.
n := n – 1.
]
].

?shufflePanPositions varIfTrue: [

shuffler value: panPositions .
]

ifFalse: [ nil ].

“self debug: panPositions.”

(inputs at: 1)
start: 0 s
panPositions: panPositions

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