Array indexing: improved safety with modular arithmetic: Difference between revisions

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(Created page with "Category:Proposals Instead of an error being triggered if an array access is outside its bounds: <pre> Prelude Data.Array> array (0, 1) (zip [0, 1] [False, True]) ! 2 *...")
 
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[[Category:Proposals]]


Instead of an error being triggered if an array access is outside its bounds:
<pre>
Prelude Data.Array> array (0, 1) (zip [0, 1] [False, True]) ! 2
*** Exception: Ix{Integer}.index: Index (2) out of range ((0,1))
</pre>
use the given index modulo the array's length:
<pre>
Prelude Data.Array> array (0, 1) (zip [0, 1] [False, True]) ! 2
False
</pre>
As an added benefit, accessing the end elements of an array would be simplified:
<pre>
Prelude Data.Array> [ array (0, 25) (zip [0..25] ['a'..'z']) ! n | n <- [-1, -2 .. -8] ]
"zyxwvuts"
</pre>
[[User:Atravers|Atravers]] 04:54, 19 January 2019 (UTC)

Latest revision as of 06:55, 20 January 2019

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