On Tue, Jul 13, 2004 at 03:16:39PM +0100, Simon Marlow wrote:
On 13 July 2004 15:02, Peter Simons wrote:
ghci-6.3 (from CVS) shows me strictness information when I request :info for a data type, like:
[...] Send Mailbox Stricts: _ [...]
I have no idea how to read that output, and it doesn't seem to be documented in the manual either. Does the underscore signify that (in the example above) Mailbox is a strict value? Or is it the opposite?
Sorry if this is a dumb question, but I simply don't know it. :-)
I don't think :info is working properly in the HEAD right now. It's something we need to fix before 6.4. I suggest just ignoring the spurious output for now.
Based on ":info Maybe" and ":info Complex.Complex" the info looks right to me, with _ meaning non-strict and ! meaning strict. Presumable you mean that it should print just "Send Mailbox" or "Send !Mailbox"? I assume this is just what you told GHC when you defined the type, though, rather than telling you anything about optimisations GHC has done. Also, it looks like :info doesn't work for tuples: Prelude> :info (,,) -- *** Exception: No match in record selector TyCon.algTyConRhs Thanks Ian