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Merge pull request #1605 from iacore/patch-2

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Patch try to accept (try body ([] catch-body))
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Calvin Rose 2025-06-29 10:01:32 -05:00 committed by GitHub
commit 58b1491592
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1 changed files with 17 additions and 16 deletions
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src/boot/boot.janet
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@ -290,22 +290,6 @@
(array/concat accum body) (array/concat accum body)
(tuple/slice accum 0)) (tuple/slice accum 0))
(defmacro try
``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.``
[body catch]
(let [[[err fib]] catch
f (gensym)
r (gensym)]
~(let [,f (,fiber/new (fn :try [] ,body) :ie)
,r (,resume ,f)]
(if (,= (,fiber/status ,f) :error)
(do (def ,err ,r) ,(if fib ~(def ,fib ,f)) ,;(tuple/slice catch 1))
,r))))
(defmacro protect (defmacro protect
`Evaluate expressions, while capturing any errors. Evaluates to a tuple `Evaluate expressions, while capturing any errors. Evaluates to a tuple
of two elements. The first element is true if successful, false if an of two elements. The first element is true if successful, false if an
@ -352,6 +336,23 @@
(tuple 'if $fi $fi ret)))))) (tuple 'if $fi $fi ret))))))
ret) ret)
(defmacro try
``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.``
[body catch]
(assert (and (not (empty? catch)) (indexed? (catch 0))) "the first element of `catch` must be a tuple or array")
(let [[err fib] (catch 0)
r (or err (gensym))
f (or fib (gensym))]
~(let [,f (,fiber/new (fn :try [] ,body) :ie)
,r (,resume ,f)]
(if (,= (,fiber/status ,f) :error)
(do ,;(tuple/slice catch 1))
,r))))
(defmacro with-syms (defmacro with-syms
"Evaluates `body` with each symbol in `syms` bound to a generated, unique symbol." "Evaluates `body` with each symbol in `syms` bound to a generated, unique symbol."
[syms & body] [syms & body]