Daniel Peebles wrote:
>
> I vaguely remember on IRC someone pointing out that the Parsec monad
> broke one of the laws. I think return _|_ >> x === _|_ which could be
> causing your problem. I may be wrong though.
>
>
Confirmed, working in the parsec monad
Prelude Text.Parsec> runP (do {x <- return undefined; return 10}) () "" ""
*** Exception: Prelude.undefined
In the IO Monad
Prelude Text.Parsec> do {x <- return undefined; return 10}
10
Should be fixed.
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