[clean-list] Re: Synonym types as instances

[Brian Rogoff]

It was for exactly this reason that I asked some similar questions last
summer, under the subject of 

Re: More translation questions (Was Re: [clean-list] translation of Haskell
 newtype?)

Here is John's helpful reply:

John van Groningen writes:
> Brian Rogoff wrote:
> > [... how to translate Haskell's newtype into Clean? ..] 
> The Clean compiler does not optimise this special case (a type with a
> single strict unary constructor). However the compiler attempts to optimise 
> a record with a single (strict) field, by unboxing such a record if it 
> appears as a strict field in (another) record, or as a strict argument of
> a constructor.
> Strict arguments and results of functions are also unboxed for records.
> 
> So it is better to translate newtype into a record with a strict field,
> instead of a constructor.
> 
> If you prefer to use a constructor like syntax, you could use a macro:
> 
> NewType a :== {new_type=a}

-- 
-- Brian