StoppingList-class: Stop based on multiple stopping rules
In 0liver0815/onc-crmpack-test: Object-Oriented Implementation of CRM Designs

This class can be used to combine multiple stopping rules.

stopList contains all stopping rules, which are again objects of class Stopping, and the summary is a function taking a logical vector of the size of stopList and returning a single logical value. For example, if the function all is given as summary function, then this means that all stopping rules must be fulfilled in order that the result of this rule is to stop.

stopList: list of stopping rules
summary: the summary function to combine the results of the stopping rules into a single result

# Define some stopping rules
myStopping1 <- StoppingMinCohorts(nCohorts=3)
myStopping2 <- StoppingTargetProb(target=c(0.2, 0.35),
                                  prob=0.5)
myStopping3 <- StoppingMinPatients(nPatients=20)

# Create a list of stopping rules (of class 'StoppingList') which will then be
# summarized (in this specific example) with the 'any' function, meaning that the study 
# would be stopped if 'any' of the single stopping rules is TRUE.
mystopping <- StoppingList(stopList=c(myStopping1,myStopping2,myStopping3),
                           summary=any)