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[ ghc-Bugs-1247773 ] when typing expression fails, don't try to Show it: msg#00144

lang.haskell.glasgow.bugs

Subject: [ ghc-Bugs-1247773 ] when typing expression fails, don't try to Show it

Bugs item #1247773, was opened at 2005-07-29 19:15
Message generated for change (Tracker Item Submitted) made by Item Submitter
You can respond by visiting:
https://sourceforge.net/tracker/?func=detail&atid=108032&aid=1247773&group_id=8032

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Category: GHCi
Group: None
Status: Open
Resolution: None
Priority: 5
Submitted By: Andrew Pimlott (pimlott)
Assigned to: Nobody/Anonymous (nobody)
Summary: when typing expression fails, don't try to Show it

Initial Comment:
Enter a ghci session, and run "print id":

Prelude> print id

Top level:
No instance for (Show (IO ()))
arising from use of `print' at Top level
Probable fix: add an instance declaration for (Show
(IO ()))
In a 'do' expression: print it

<interactive>:1:0:
No instance for (Show (a -> a))
arising from use of `print' at <interactive>:1:0-4
Probable fix: add an instance declaration for (Show
(a -> a))
In the definition of `it': it = print id

It would be nice to make the first error go away. It
looks as if, when typing "print id" fails, ghci
nonetheless goes ahead and tries to type "let it =
print id; print it", or something. This just creates
useless noise.

----------------------------------------------------------------------

You can respond by visiting:
https://sourceforge.net/tracker/?func=detail&atid=108032&aid=1247773&group_id=8032


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