On Fri, 7 Dec 2001, Adrian Hey wrote:
The first is.. Does the compiler keep a unique copy of expressions which consist of just a single zero arity constructor (eg. [],True,Nothing..) as a CAF which is referenced each time the constructor appears in an expression, or does it duplicate the constructor (expression) each time it's used. Maybe I should define my own CAF at the top level and use it instead? (or perhaps they're unboxed somehow?)
Really idle curiosity... why would having a single copy of a zero arity constructor be more efficient than have multiple copies? Wouldn't they fit into a `cell' which wouldn't be larger than the one that would (IIRC) be used for the indirection to the CAF? (I can understand a larger CAF being a win, but one this small?) ___cheers,_dave_________________________________________________________ www.cs.bris.ac.uk/~tweed/|`...heat generated by its microprocessors will email:tweed@cs.bris.ac.uk|slope upward exponentially, reaching the power work tel:(0117) 954-5250 |density of a nuclear reactor before 2010'-Intel