Collation case level examples debug

[echeran]

When creating docs examples for the case level setting in collation options for collator (#2447), I couldn't seem to create examples that returned distinct outputs from primary strength versus secondary strength.

The examples in #2447 are adapted from the examples provided in the ICU User Guide for case level, partly due to not being able to get the code to produce the output expected based on the User Guide.

Is the application of case-level in collation broken? Or is it a problem of not knowing how to use it?

[markusicu]

I suggest you try this list of strings and compare each with the next:

• ⓓⓔⓐⓛ
• DEAL
• dejavu
• dejAvu
• déjavu

The last two trade places in the sort order depending on the settings:

• primary+case ignores the accent difference so dejAvu will compare greatest
• secondary+case has the accent difference win over the case difference

---

This is a bug:

assert_eq!(primary_and_case.compare("DEAL", "ⓓⓔⓐⓛ"), Ordering::Equal);

This should yield Greater.

[echeran]

@markusicu - Thanks! I incorporated some of that into PR #2447.

Note to self/others: Leave this issue open for the bug identified in the comment above.

[markusicu]

@markusicu - Thanks! I incorporated some of that into PR #2447.

Nice.

Note to self/others: Leave this issue open for the bug identified in the comment above.

That is now visible on two lines in the above PR:

//! assert_eq!(primary_and_case.compare("ⓓⓔⓐⓛ", "DEAL"), Ordering::Equal);
...
//! assert_eq!(primary_and_case.compare("déjavu", "dejAvu"), Ordering::Equal);

[echeran]

This issue was reported again in #2884 , which was fixed by #2892. Closing this as duplicated and fixed.