Steven D'Aprano <[EMAIL PROTECTED]> writes: > > That still sounds like an unreliable manual type system, > It's unreliable in the sense that the coder has to follow the naming > convention, and must have some bare minimum of sense. If your coders are > morons, no naming convention will save you. (For that matter, nothing will > save you.)
Well, type systems in programming languages have generally proven more reliable and easier to deal with than having programmers track it all manually-- that's why we don't all write in Forth ;-). > But dimensioned units are still only part of the story. Joel describes the > situation the early Word developers found: when you're writing a word > processor, you are doing a LOT of conversions between screen coordinates > and window pane coordinates. Both have the same type (a pair of ints), > both have the same dimensional units (length/pixels) but they are > semantically different. If you place the character "N" at coordinates 0,0, > it makes a big difference if the coordinates are relative to the current > window or relative to the screen. You're right that this is not exactly dimensional analysis, but it still seems to call for types and conversion functions, rather than naming conventions. I guess they were writing that stuff in C++, so I'd have expected the compiler to handle the conversions through casts with no runtime cost except when an actual conversion was needed. In Haskell I believe it would be similar. -- http://mail.python.org/mailman/listinfo/python-list
