My take on this for list-like structures:
1. Since the potential for hard to track errors is so high - and for
least surprise - default behavior should always be to throw on
out-of-bounds access.
2. Returning a default value for out of bound access can be very
conventient, but should be made explicit; we e.g. use the following
naming convention in our code in this case:
1. getWithDefault(index, defaultVal)
1. We don't need that, but a more general version might be:
getWithDefault(index, defaultValClosure)
2. getWithNullDefault(index)
3. Automatically extending the size seems to be the worst option, given
that one too large index access could easily exhaust a computer's
main memory (-:
Cheers,
mg
On 06/02/2025 17:27, Milles, Eric (TR Technology) via dev wrote:
Is there any explicit statement about how indexing beyond the end of a
collection should work? Does it extend the collection or just return
null. Does a withDefault collection do something different?
In general, arrays and collections should work the same, so the
statement in the working with arrays section is a good one. In the
matter of indexing beyond the end of the array or collection, what is
the shared behavior supposed to be:
1.
return default value for type — aka null for reference and 0/false
for primitives
2.
throw out-of-bounds exception
3.
something else?
------------------------------------------------------------------------
*From:* OCsite <o...@ocs.cz>
*Sent:* Thursday, February 6, 2025 10:11 AM
*To:* dev@groovy.apache.org <dev@groovy.apache.org>
*Subject:* [EXT] Re: a bug or my fault?
*External Email:* Use caution with links and attachments.
The overall intention is that whether you are using an array or a
collection, the code for working with the aggregate remains the same
<https://urldefense.com/v3/__https://docs.groovy-lang.org/latest/html/documentation/*_working_with_arrays__;Iw!!GFN0sa3rsbfR8OLyAw!ezrONlzs3yG6lC6cFTDF2ASi61brEmoT2ix7QriL2Tg7vhHIhMXTwpPoYFbS77qNBafdycrQlnIZgRDxsA$>.
In this particular case alas that good and noble intention does not
quite work, and I wonder whether that is intentional (forgive the pun)
or a mistake to be fixed in future, when there's nothing more pressing
to do.
On 6. 2. 2025, at 13:30, Søren Berg Glasius <soe...@glasius.dk> wrote:
You assign 'b' as an Array, and arrays works differently than
lists. Arrays are bound to their length, so 'a[2]' should report
out of bounds as it is not 3 elements long, whereas a list b[2]
would report null
IMO it's working as intended.
Den tors. 6. feb. 2025 kl. 10.20 skrev OCsite <o...@ocs.cz
<mailto:o...@ocs.cz>>:
Hi there,
is this inconsistence intentional and the proper Groovy
behaviour, or is that a bug and should I add a jira ticket?
Thanks!
===
*groovy:*000*>* a=[1,2]
*===>* [1, 2]
*groovy:*000*>* b=a as Object[]
*===>* [1, 2]
*groovy:*000*>* a[2]
*===>* null
*groovy:*000*>* b[2]
*ERROR* java.lang.ArrayIndexOutOfBoundsException:
*Index 2 out of bounds for length 2*
*groovy:*000*>*
===
--
Med venlig hilsen,
Søren Berg Glasius
Hedevej 1, Gl. Rye, 8680 Ry
Mobile: +45 40 44 91 88
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