The proper init script

[Nala Ginrut]

Hi folks!
I'm implementing Lua front-end seriously. However, I'd like to make sure
the module is pure without any predefined Scheme procedures. Because the
predefined 'string' object conflicts with 'string' procedure of Scheme.

For Lua script running or compilation, I can set a generator with
#:make-default-environment in language spec.scm. And it works fine.

However, I want to run this code in the REPL when I switch to Lua language.
--------------------------------code-----------------------------------
(set-current-module (define-module* '(lua) #:pure #t))
---------------------------------end------------------------------------
Of course, I can run it first, then switch to Lua, and it works.
Now my question is, how can it run automatically when I switch the language?

I've tried '.guile`, and it seems useless.
How can I do it properly?

Best regards.