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<DIV><FONT size=2 face=Arial><SPAN class=796202117-24102012>A year ago I made a
program. I took code from ApplicativeParsec.hs (capt. 16 Real
World Haskell).</SPAN></FONT></DIV>
<DIV><FONT size=2 face=Arial><SPAN class=796202117-24102012>The program
compiled and ran flawless. Now (after a year) I've upgraded to GHC version
7.0.4 (Windows) and I want to change something. But the unchanged
version doesn't compile any more. I get warning:</SPAN></FONT></DIV>
<DIV><FONT size=2 face=Arial><SPAN
class=796202117-24102012>ApplicativeParsec.hs:17:10:<BR>
Illegal instance declaration for `Applicative (GenParser s
a)'<BR> (All instance types must be of the form (T
t1 ... tn)<BR> where T is not a
synonym.<BR> Use -XTypeSynonymInstances if
you want to disable this.)<BR> In the instance declaration for
`Applicative (GenParser s a)'</SPAN></FONT></DIV>
<DIV><FONT size=2 face=Arial></FONT> </DIV>
<DIV><FONT size=2 face=Arial><SPAN
class=796202117-24102012>ApplicativeParsec.hs:22:10:<BR>
Illegal instance declaration for `Alternative ....(same advice
as above)</SPAN></FONT></DIV>
<DIV><FONT size=2 face=Arial><SPAN
class=796202117-24102012></SPAN></FONT> </DIV>
<DIV><FONT size=2 face=Arial><SPAN class=796202117-24102012>So I added
TypeSynonymInstances. Then I got:</SPAN></FONT></DIV>
<DIV><FONT size=2 face=Arial><SPAN
class=796202117-24102012>ApplicativeParsec.hs:22:10:<BR>
Overlapping instances for Applicative (GenParser s
a)<BR> arising from the superclasses of an
instance declaration<BR> Matching
instances:<BR> instance Applicative
(Text.Parsec.Prim.ParsecT s u m)<BR>
-- Defined in Text.Parsec.Prim<BR> instance
Applicative (GenParser s a)<BR> --
Defined at ApplicativeParsec.hs:17:10-36<BR> In the instance
declaration for `Alternative (GenParser s a)'</SPAN></FONT></DIV>
<DIV><FONT size=2 face=Arial><SPAN
class=796202117-24102012></SPAN></FONT> </DIV>
<DIV><FONT size=2 face=Arial><SPAN class=796202117-24102012>Then I added the
OverlappingInstances directive. Same error and no
compilation.</SPAN></FONT></DIV>
<DIV><FONT size=2 face=Arial><SPAN
class=796202117-24102012></SPAN></FONT> </DIV>
<DIV><FONT size=2 face=Arial><SPAN class=796202117-24102012>I wonder, is this
the new GHC version? And what can I do about it?</SPAN></FONT></DIV>
<DIV><FONT size=2 face=Arial><SPAN
class=796202117-24102012></SPAN></FONT> </DIV>
<DIV><FONT size=2 face=Arial><SPAN
class=796202117-24102012>Kees</SPAN></FONT></DIV>
<DIV><FONT size=2 face=Arial><SPAN
class=796202117-24102012></SPAN></FONT> </DIV></BODY></HTML>