joy-framework / joy

A full stack web framework written in janet
https://joy.swlkr.com
MIT License
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Doc update: rescue cannot be used in macro chains #91

Open LeviSchuck opened 3 years ago

LeviSchuck commented 3 years ago

I found the code in the authentication docs https://github.com/joy-framework/joy/blob/6ede2012c0aa0f9c524c3c869cd1787217c1ecd5/docs/authentication.md to not work here (also there is a typo, an extra parentheses after the ?)

(defn create [request]
  (let [[_ account-params] (as-> request ?)
                                 (params ?)
                                 (rescue ?))

The body of the try block in rescue is not executed in this style. Instead, it has to wrap around the whole pipe chain with as->

(defn create [request]
  (let [[_ account-params] (rescue (as-> request ?
                                 (params ?)))

Locally I verified behavior by replacing rescue with the following

(defmacro rescue [f &opt id]
  ~(try
     (do (eprintf "About to run rescue") [nil ,f])
     ([err fib]
      (eprintf "Rescuing maybe %p" err)
      (if (and (dictionary? err)
            (or (truthy? (get err :id))
              (= ,id (get err :id))))
        [(get err :error) nil]
        (do
          (eprintf "Propigating error %p" err)
          (propagate err fib)
         )
))))

I'll probably update my example project later with working features.

swlkr commented 3 years ago

I updated that authentication doc so hopefully it represents a working example like yours