value restriction
noun1
Computer, Computing, Engineering, Mathematics, Natural sciences, Physical sciences, Science, Sciences In a functional language, inference of a polymorphic type only for syntactic values (values that can be evaluated at compile time) to ensure that a program is type-safe.
- A typical example is an expression returning always the empty list. It should be given the polymorphic type α list, but this is not possible under the value restriction if the expression has to be evaluated.2004, Jacques Garrigue, Relaxing the Value Restriction:
- It has been found empirically that eta expansion usually suffices for dealing with the value restriction.2007, Geoffrey Smith, Notes on SML97's Value Restriction: