| ||The Order of Evaluation - slide 17 : 26|
We will here describe the practical consequences of the theoretical results mentioned on the previous page
- During the evaluation of an expression, it will never be necessary to backtrack the evaluation process
in order to reach a normal form.
- An expression cannot be converted to two different normal forms (modulo alpha conversions, of course).
- If an expression e somehow can be reduced to f in one or more steps, f can be reached by
normal order reduction - but not necessarily by applicative order reduction
Normal-order reduction is more powerful than the applicative-order reduction
Scheme and ML uses applicative-order reduction
Haskell is an example of a functional programming language with normal-order reduction