[Haskell-cafe] When does the UNPACK pragma work?

[Daniel Fischer]

On Friday 28 October 2011, 11:57:54, Eugene Kirpichov wrote:
> Another question: Can I unpack some fields in a record and not unpack
> others?

Yes, no problem with that. 

> Does their order matter then?

In what way? The order of the fields in the definition of the type will 
determine the order in which the components (pointers/unpacked values) 
appear in the constructor. That may influence performance, but I wouldn't 
expect a significant difference.