2007/6/28, Pasqualino 'Titto' Assini
On Wednesday 27 June 2007 23:28:44 oleg@pobox.com wrote:
In his system, the type of the matrix includes includes the matrix size and dimensions, so invalid operations like improper matrix multiplication can be rejected statically. And yet, his library permits matrices read from files.
Read from files but still at compile time, correct?
(titto, sorry for dupliate) No, what is meant, I believe, is reading from a file at run-time and parsing this way (u :: UnTyped) <- readFromFile case parse u of Nothing -> -- failed to parse, because those data wouldn't satisfy constraints Just (t::Typed) -> -- if we're here, we have the typed t, and there are garantees that it is well formed -- in terms of our invariants parse :: UnTyped -> Maybe Typed so deciding whether we have correct data is made at run-time, by calling parse and examining its return value.