Testing for variant/version

[Joseph Wright]

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