Bindings and Space leaks

Hello, I've got two questions regarding bindings in Haskell: 1. Is there something like a strict "let!" for avoiding function closures by forcing strict evaluation (to headnormalform) of local declarations? 2. In a '93 paper, Jan Sparud describes an implementation technique for avoiding space leaks when tuples are returned as function result, and the values accessed by pattern matching in bindings. The paper says this technique (of shorcircuiting all references via a tuple, the first time a tuple element is demanded) has been implemented in Chalmers LML/HBC compiler. What about other compilers, e.g. GHC? Any hint would be helpful. Thanks, Janis. -- Janis Voigtlaender email: voigt@tcs.inf.tu-dresden.de