I have a type
Handler [Maybe AvailableDay]
I would like to inspect the contents of [Maybe AvailableDay] in ghci. How do I do that?
I have a type Handler [Maybe AvailableDay] I would like to inspect the contents
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I have a type
Handler [Maybe AvailableDay]
I would like to inspect the contents of [Maybe AvailableDay] in ghci. How do I do that?
You cannot simply extract the “contents” of a
Handler, as aHandleris really a computation which can depend on the current request, session state and so on. So in order to run it, you’d have to feed it all of that. This would involve usingrunHandler, followed byunYesodApp, andrunon the resultingIteratee. Technically possible, but incredibly messy to do on your own.If you don’t think the value is depending on any of that, then you should be able to rewrite it as a pure computation or one in the
IOmonad, which should be a lot simpler to run.