1 --!!! Testing typechecker (fixed in Hugs 1.01)
6 While I am at bug reporting I should as well inform you of another
7 problem that I encountered.
9 While testing different variations of the gc-bug test program I
10 found a difference between what would compile in the original hugs.1.01
11 and the hacked.hugs that I downloaded from the ftp directory.
13 In the hacked.hugs I have only changed: SUNOS 0, LINUX 1, and finally
14 I had to remove the external definition of strchr because it conflicted
15 with some include file definition. (Of course this will turn out
16 to be the reason, right?)
18 I also had to add the Ordering type in hugs.prelude that came with
19 hacked.hugs.tar.gz, because it was required to be loaded.
27 The error message was:
29 ERROR "/home/nilsson/ngof/simpleprims/src/tbugx.gs" (line 15): Insufficient class constraints in instance member binding
30 *** Context : (T a, T b, T c)
33 The test program, tbugx.gs, is:
36 module TestTypes where
44 instance (T a, T b) => T (a, b) where
49 instance (T a, T b, T c) => T (a, b, c) where
50 -- The following compiles in hugs1.01, but not in hacked.hugs!
51 -- It induces the GC bug as well.
58 -- The following does not induce the GC bug.
59 -- But as the previous one, it compiles only in hugs1.01, not in hacked.hugs.
60 -- t p = (a, b, c) where
67 t2 = t -- t2 has no problems
69 t3:: Int -> (Int,Int,Int)
70 t3 = t -- t3 has problems