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Diffstat (limited to 'testsuite/tests/typecheck/should_compile/tc096.hs')
-rw-r--r-- | testsuite/tests/typecheck/should_compile/tc096.hs | 36 |
1 files changed, 36 insertions, 0 deletions
diff --git a/testsuite/tests/typecheck/should_compile/tc096.hs b/testsuite/tests/typecheck/should_compile/tc096.hs new file mode 100644 index 0000000000..165c5bd636 --- /dev/null +++ b/testsuite/tests/typecheck/should_compile/tc096.hs @@ -0,0 +1,36 @@ +module ShouldSucceed where + +-- !!! monomorphism restriction and defaulting + +x = 3 + +main = print $ 6 / x + +{- +Hugs 1.4 complains: ERROR "Strange.hs" (line 3): Int is not an +instance of class "Fractional". GHC however compiles the program. +Substitute for x and Hugs is happy. What's going on? + +I haven't studied the numeric classes much so perhaps I'm missing +something obvious here. (I see that the bugs page alludes to some 1.4 +features not in Hugs leading to type errors. If this is it, maybe you +should give it as an example?) + + Bjarte + +------- Message 2 + +Date: Wed, 25 Feb 98 14:01:35 -0500 +From: "John C. Peterson" <peterson-john@CS.YALE.EDU> +To: bjartem@idi.ntnu.no +cc: hugs-bugs@CS.YALE.EDU +Subject: Re: Fractional and Int? + +This is a known hugs bug. x should be monomorphic, allowing the usage +in main to constrain it to Fractional. Instead, it is generalized and +then defaulted to Int without being influenced by main. So ghc is +right and hugs is wrong on this one. I expect this will be fixed +eventually. + + John +-} |