# I need the opposite of \`..\<index\`, why is there no \`index\>..\`?

**URL:** <https://forums.swift.org/t/i-need-the-opposite-of-index-why-is-there-no-index/48186>\
**Category:** Using Swift\
**Created:** [May 11, 2021, 6:05pm UTC](https://forums.swift.org/t/i-need-the-opposite-of-index-why-is-there-no-index/48186 "2021-05-11T18:05:37Z")\
**Posts on this page:** 1\
**Showing post:** 10

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**Author:** ![wowbagger](https://sea2.discourse-cdn.com/swift/user_avatar/forums.swift.org/wowbagger/32/13847_2.png) [@wowbagger](https://forums.swift.org/u/wowbagger)\
**Post date:** [May 11, 2021, 7:20pm UTC](https://forums.swift.org/t/i-need-the-opposite-of-index-why-is-there-no-index/48186/10 "2021-05-11T19:20:46Z")

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> [@young](#):
>
> Why no `index>..` ? Is there anyway to write this postfix operator?

As @Lantua explained up-thread

> [@Lantua](#):
>
> `<..` isn't a valid operator right now as dot-operator must begin with dot.

And expanding on it a bit, this is because of the limit of [character combinations allowed](https://docs.swift.org/swift-book/ReferenceManual/LexicalStructure.html#ID418) in an operator for it to be parsed unambiguously.

If you need left-open right-closed intervals, I have an incomplete library [`Interval`](https://github.com/WowbaggersLiquidLunch/Interval) on GitHub. However, it has some significant [disadvantages](https://forums.swift.org/t/unify-and-expand-range-and-its-likes/38427/4) compared to `RangeExpression` types.

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