| If you are used to the notion of an abstract data type, defined by a type and a set of operations, and then you decide you want to support extensibility of abstract data types, then you end up at something very much like Ada 95, Haskell, or CLOS, with the "operation(operand, operand, ...)" or "operand operand" or "object := operation(operand, operand,...)" syntax familiar from theoretical mathematics and logic.
If you instead focus on updating objects as the primary operations of interest, then you end up with the . syntax.
In some ways, the Ada 95 syntax is more sympathetic with the "value-oriented" (i.e. functional) way of thinking than the "object-oriented" (i.e. side-effecting) way of thinking.
The net effect, in any case, is that you can more easily write in a "functional" style in Ada 95 where there is less use of heap-resident read/write objects, and more use of values (rather than objects) of an abstract type being passed around, assigned, declared, etc.
(Tucker Taft) |
