[
https://issues.apache.org/jira/browse/GROOVY-11636?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17947435#comment-17947435
]
Paul King commented on GROOVY-11636:
------------------------------------
Some more examples (existing):
{code:groovy}
{code:java}
assert '𝔸'.next() == '𝔹'
assert '報'.next() == '堲'
assert '❤️'.next() == '❤︐' // ❤️ = ♥ + red variation selector
{code}
We could try to change the existing behavior to try to use codepoints rather
than characters (but there is no setCodePointAt or deleteCodePointAt
equivalents, plus codepoints don't really handle all cases like the heart emoji
case anyway.
It is useful to look at recent advice about working with
chars/codepoints/single grapheme characters:
[https://www.javaadvent.com/2020/12/confusing-java-strings.html]
[https://horstmann.com/unblog/2023-10-03/index.html]
TL;DR version: we have to wait until Java 20 before we can iterate efficiently
over grapheme clusters. For Groovy 5, we could use the regex
{{s.split(/\b\{g}/)}} (Java 9+), but we'd have to do our own stringbuilder
equivalent code and handle the delete/set operations ourselves. And that
wouldn't deal with the multi-character emojis. So, my suggestion is to just
provide the simple char case.
> Create SGM#next/previous methods which act like next/previous but also takes
> an integer repeat count
> ----------------------------------------------------------------------------------------------------
>
> Key: GROOVY-11636
> URL: https://issues.apache.org/jira/browse/GROOVY-11636
> Project: Groovy
> Issue Type: New Feature
> Reporter: Paul King
> Assignee: Paul King
> Priority: Major
>
> Trying to get from String 'a' to 'e' by "adding 4" can be cumbersome, either
> calling next() multiple times, or converting to a char, doing the arithmetic,
> then converting back.
> The idea would be to support:
> {code:groovy}
> assert 'a'.next(0) == 'a'
> assert 'a'.next(4) == 'e'
> assert 'a'.next(0) == 'a'
> assert 'a'.next(25) == 'z'
> assert 'A'.next(32) == 'a'
> assert (0..4).collect('a'::next) == 'a'..'e'
> assert 'car'.next(2) == 'cat'
> {code}
> Although hopefully never used, this piggybacks on the normal next() wrapping
> behavior if Character.MAX_VALUE is reached. And also, like next(), applies
> the the last character in a longer String as per last test above.
--
This message was sent by Atlassian Jira
(v8.20.10#820010)
