Timeline for filter + map api design
Current License: CC BY-SA 4.0
11 events
| when toggle format | what | by | license | comment | |
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| Mar 6, 2019 at 7:51 | vote | accept | CommunityBot | ||
| Mar 5, 2019 at 2:07 | comment | added | user290257 |
@KarlBielefeldt thanks, your java.util.Optional idea was a good one and worked for me, see my answer
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| Mar 4, 2019 at 0:28 | comment | added | Karl Bielefeldt |
I'm not very familiar with Java, but I think you would want Optional.empty when you want to omit the item, and Optional.of to include it.
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| Mar 3, 2019 at 22:42 | comment | added | user286798 |
so something like return new Optional<>() (would essentially return false) and return new Optional<>(someValue) would represent true, and the value to be mapped to would be someValue? is that about right?
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| Mar 1, 2019 at 19:54 | comment | added | Karl Bielefeldt | An option is a type in some libraries that indicates either the presence or absence of a value. For example, Optional in Java. | |
| Mar 1, 2019 at 18:37 | comment | added | user290257 |
you said use an empty array (or option) if you want to exclude the item - what do you mean by option?
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| Mar 1, 2019 at 11:38 | comment | added | Bossie |
@MrCholo: flatMap maps elements to arrays, then flattens these arrays, where an empty array is flattened to nothing. Think of flatMap as a more general version of map, in that it can return 0 to N elements, instead of exactly 1 like map.
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| Mar 1, 2019 at 9:23 | comment | added | user290257 | so the empty array represents false (filter it out)? Not sure I get it...what if the input array was made up of arrays? | |
| Mar 1, 2019 at 5:20 | comment | added | Karl Bielefeldt | It does coerce, but you're right that would be technically more correct. | |
| Mar 1, 2019 at 5:09 | comment | added | Bossie |
I believe it should be [x / 2], unless JavaScript does some kind of type coercion in this case.
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| Mar 1, 2019 at 5:04 | history | answered | Karl Bielefeldt | CC BY-SA 4.0 |