Testing for variant/version

[Joseph Wright]

On 09/04/2024 16:48, Joseph Wright wrote:
> On 09/04/2024 16:33, Peter Flynn wrote:
>> On 09/04/2024 10:58, David Carlisle wrote:
>>
>>> You can use
>>> \ExplSyntaxOn
>>> \str_compare:nNnTF {aaay} < {aaax} {yes} {no}
>>> \ExplSyntaxOff
>>>
>>> The latex format has already tested which engine you are using and
>>> resolved differences between the primitive name and/or supplied Lua
>>> implementation where needed, so you don't need to load any packages
>>> or re-test or load another lua emulation.
>>
>> Excellent, thank you. What version does this date from?
>
> David has the name slightly wrong :) \str_if_eq:nnTF is what he meant,
> it's been around for ever (>10 years back to when I joined the team or
> perhaps before).
>
> Joseph

David points out we do have \str_compare:nNnTf from 2021-05-25 :)

Joseph