Cannot ^C out of certain computations in GHCi

[lepsmith@…]

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 / /_\// /_/ / /  | |      GHC Interactive, version 6.6.1, for Haskell 98.
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Prelude> let a = 1 : a
Prelude> last a
^C
^C
^C

[Isaac Dupree]

Maybe this is related to (in compiled code, which last is) loops that do no allocation not being pre-emptible. Possibly it is a simplified version of #1583 where the computation never terminates, so GHCi never gets around to the <interactive>: exception :: GhcException state (I couldn't get ghci to respond in any way, even after lots of Control-C's, in this last example).

[Isaac Dupree]

Doing it purely in GHCi does not suffer this problem:

Prelude> let a = 1 : a
Prelude> let last [x] = x; last (_:xs) = last xs
Prelude> last a
^C
Interrupted.

[simonmar]

duplicate of #367. Or at least the cause is the same, and fixing this would involve fixing #367.