I'm considering putting in some effort to generalize the binding construct in
for-clauses so that we can have for[*]/match/X macros. This will require
modifying and exposing define-for-variants (due to circularity in requiring
match in for). Does anyone object? I'll of course need the code reviewed by
those more familiar with for, but I'm hoping I don't need to mess with
complicated implementation details such as taints.
Example:
Here the significantly new behavior is that name should match in the for/match
clauses in order to run the body.
(for* ([mch (redex-match L some-pat some-term)]
[bnds (match-bindings mch)]
[use-names (in-value use-names)])
(for/match ([(bind name exp) bnds]
[name use-names])
...code...))
What this looks like without for/match is
(for* ([mch (redex-match L some-pat some-term)]
[bnds (match-bindings mch)]
[use-names (in-value use-names)])
(for ([bnd bnds]
[name use-names]
#:when (match* (bnd name) [((bind nm _) nm) #t] [(_ _) #f]))
(match-define-values ((name exp) name) (values bnd name))
...code...))
Notice the unnecessary second match.
-Ian
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