The syntax/for-body module provides a helper function for for-like syntactic forms that wrap the body of the form while expanding to another for-like form, and the wrapper should apply only after the last #:break or #:final clause in the body.

The body-stxes argument must have the form (pre-body ... post-body ...), and it is rewritten into ((pre-body ...) (post-body ...)) such that (post-body ...) is as large as possible without containing a #:break or #:final clause.