The current evaluation mechanism.
The name of the current evaluation mechanism (default: "reduce")
Return the names of the available evaluation mechanisms.
Change the current evaluation mechanism to that denoted by mech if it is a legal one, otherwise do nothing.
Change the current evaluation mechanism to that denoted by mech if it is a legal one, otherwise do nothing. Returns whether the change could be made or not.
Interface to switchable evaluators for the lambda2 language. Enables a client to select an evaluation mechanism by name and access the evaluator for that mechanism.