macro
boot.janet on line 339 , column 1
(try body catch )
Try something and catch errors. `body` is any expression , and
`catch` should be a form , the first element of which is a tuple.
This tuple should contain a binding for errors and an optional
binding for the fiber wrapping the body. Returns the result of
`body` if no error , or the result of `catch` if an error.
# catch and propagate an error with fiber
(try
( 1 nil )
([err fib ]
(propagate err fib )))