[racket] Racket forward compatability

Is there any assurance3 that a program written with Racket wil work with a
future version of Racket?  I expect the short answer is: No.
Any related comments are appreciated.
I am using Racket version 5.2.1.
I have found that regexp functions are too slow for large data files but
maybe newer versions have made a change that would speed things up.  (I
read something about some solution from github but I am not sure that is
something I should look into.)  I'd rather just install a new version of
Racket at an appropriate stage, namely when my current project development
has concluded.  My current work around is a call to an external program
which provides the regexp function at the speed needed.
Thanks for any comment(s).
Don Green
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