Proposal: Add Text.Read.maybeRead :: Read a => String -> Maybe a

Henning Thielemann lemming at henning-thielemann.de
Thu Feb 7 15:18:25 EST 2008


On Thu, 7 Feb 2008, Don Stewart wrote:

> This function is typically defined once per project. So its
> about time this safe variant of 'read' made it into the base.
>
>     maybeRead :: Read a => String -> Maybe a
>     maybeRead s = case reads s of
>         [(x, "")] -> Just x
>         _         -> Nothing
>
> Consideration period: 1 week.
>
> Patch to Text.Read attached.

Seems to be useful. May prevent people from using just 'read' while hoping
that parsing will always succeed.


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