Re: [Haskell-cafe] Are newtypes optimised and how much?

On 10/20/10 7:09 AM, Simon Peyton-Jones wrote:

Yes, you can freely use Foo/unFoo. There's no runtime penalty. (In the jargon of GHC's intermediate language, Foo and unFoo translate to *type-safe casts*, which generate no executable code.

When does the conversion to type-safe casts occur relative to other optimizations (namely, rewrite rules)? -- Live well, ~wren