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land* for guile


in the new srfis I've seen a new syntax form called land* , which seems to
be a hybrid between let* & and. So when an expression in a list evaluates to
true, its return value is bound in the subsequent expressions to evaluate.
Once an expression evaluates to false, the whole land* call is terminated,
returning #f. If none of the argument expressions eval to #f, the land* call
evaluates to whatever the last expression in the sequence evaluates to.
It is sure not hard to write this using a define-syntax. For performance
reason, in guile one might either wish to write it in C with libguile API
or to hobbit the result. Hobbit is very picky about what syntaces it 
accepts. But maybe it isn't that slow at all when written directly in
guile scheme. What would be the preferrable way to write a land* module
for guile?
--
Klaus Schilling