[Haskell-beginners] (SPAM 3)Re: database, list result, extraction and conversion
bkunyiha at gmail.com
Thu Dec 6 20:03:42 UTC 2018
Thank you for reaching out to me.
Is this a remote position?
I live in Los Angeles and cannot relocate.
On Thu, Dec 6, 2018 at 8:10 AM Francesco Ariis <fa-ml at ariis.it> wrote:
> On Thu, Dec 06, 2018 at 03:54:45PM +0100, Damien Mattei wrote:
> > if it was so easy!
> Damien, you must heed the compiler!
> > UpdateSidonie.hs:93:25: error:
> > • Couldn't match expected type ‘Only a’
> > with actual type ‘[Only Text]’
> > • In the first argument of ‘fromOnly’, namely ‘bd_rows’
> > In the expression: fromOnly bd_rows
> > In an equation for ‘noBD’: noBD = fromOnly bd_rows
> > • Relevant bindings include
> > noBD :: a (bound at UpdateSidonie.hs:93:9)
> > |
> > 93 | let noBD = fromOnly bd_rows
> > | ^^^^^^^
> > Failed, no modules loaded.
> So you applied `fromOnly` to `bd_rows`. fromOnly has type
> fromOnly :: Only a -> a
> Now GHC is complaining:
> • I was expecting ‘Only a’
> but you gave me ‘[Only Text]’
> So either call "head" on [Only Text] (unsafe!) or map over it.
> See if it works and if not, fire again here
> Beginners mailing list
> Beginners at haskell.org
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