[Haskell-beginners] Cabal on mac

[Daniel Fischer]

On Friday 25 November 2011, 01:32:13, Tim Pizey wrote:
> Hi,
> 
> I have installed cabal and HaxMl
> 
> cabal install HaXml
> 
> but my .hs file cannot find
> 
> import Text.XML.HaXml.Xml2Haskell (readXml)
> 
> giving
> 
> *** Chasing dependencies:
> Chasing modules from: *ch.hs
> 
> ch.hs:3:8:
>     Could not find module `Text.XML.HaXml.Xml2Haskell':
>       locations searched:
>         Text/XML/HaXml/Xml2Haskell.hs
>         Text/XML/HaXml/Xml2Haskell.lhs
> 
> It would seem only to be looking in the current directory.
> 
> Hoping I have just missed something obvious.

In a way.

Text.XML.HaXml.Xml2Haskell was in HaXml-1.13, but is no longer in HaXml 
since version 1.19 (current is 1.22.5). Old tutorial, I guess.

There are two functions with the name readXml in the new versions, in
Text.XML.HaXml.XmlContent and Text.XML.HaXml.XmlContent.Haskell
(probably the same function, just exported from both modules).

The type has changed, instead of XmlContent a => String -> Maybe a, it is 
now XmlContent a => String -> Either String a, presumably specifying the 
parse failure now if there is one, otherwise I expect the behaviour to be 
the same.