At 2001-08-21 20:31, Dean Herington wrote (on the Haskell list):
>Now realizing that the "where" keyword is optional when there are no
>accompanying declarations, I think it would be preferable to omit the
>"where" keyword to indicate that the absence of declarations is
>intentional.
Personally I prefer the explicit braces/semicolons syntax rather than
worrying about whitespace:
module DeepSeq where
{
class DeepSeq a where
{
deepSeq :: a -> b -> b;
deepSeq = seq; -- default, for simple cases
};
...
instance DeepSeq Ordering;
instance DeepSeq Integer;
instance DeepSeq Int;
instance DeepSeq Float;
instance DeepSeq Double;
}
...or if you prefer...
module DeepSeq where
{
class DeepSeq a where
{
deepSeq :: a -> b -> b;
deepSeq = seq; -- default, for simple cases
};
...
instance DeepSeq Ordering;
instance DeepSeq Integer;
instance DeepSeq Int;
instance DeepSeq Float;
instance DeepSeq Double;
}
etc.
Basically you put a braced block after every 'do', 'in' and 'where', and
semicolons after every declaration. When I was first learning Haskell, I
got massively confused by the whitespace rules, especially with mixed
tabs/spaces etc. I reckon the braces style is more readable to anyone
used to C/C++/Java etc.
--
Ashley Yakeley, Seattle WA
