selector
The base class for all different sorts of number selection policies.
The Arrays called out as method parameters is always an Array of indexes for some other list.
Get whichever number is next available.
Get whichever number is next available.
It is similar to StrictInOrderSelector but it does not stop if it runs into an unavailable number.
It attempts to get each number in its listed incrementally from a starting index.
The search wraps back around to the zero index to the same start index if necessary.
Get a pseudorandom number from a pool of numbers.
Get a pseudorandom number from a pool of numbers.
The contained logic is similar to RandomSequenceSelector.
It is not reliant of a shrinking pool that composes into some sequence of all the numbers, however;
the numbers are re-introduced to the selection as long as the pool is used.
This allows for the sequence to contain repeat numbers far before ever visiting all of the numbers once.
During the selection process:
The index is the position from where the selection begins, and the end of the Array is where the selection ends.
Once a position between those two indices is selected, that number is extracted.
The number at the start position is swapped into the position where the selection number was extracted.
The start position is then set to an invalid number, and the start index is advanced.
Repeat next request.
During the return process:
The returned number is added to the input Array at the position just before the current selection position.
The selection index is then reversedback to re-include the returned number.
The normal return index is not used in this algorithm.
RandomSequenceSelector
Get a pseudorandom number from a pool of numbers.
Get a pseudorandom number from a pool of numbers.
The output of this class, operating on an Array of Int values is contained to some sequence of all the numbers.
Only after every number is selected once, may any number repeat.
The pseudorandomness of any sequence of numbers is not only provided by an internal system Random but by the order or returned numbers.
Consequentially, as any single sequence nears completion, the numbers remaining become more and more predictable.
During the selection process:
The index is the position from where the selection begins, and the end of the Array is where the selection ends.
Once a position between those two indices is selected, that number is extracted.
The number at the start position is swapped into the position where the selection number was extracted.
The start position is then set to an invalid number, and the start index is advanced.
Repeat next request.
The return index trails behind the selection index as far as the order of the array is concerned at first.
After some time, the selection index moves to the starting position of the array again and then the order is reversed.
Until the return index wraps around to the beginning of the array too, it is considered the valid selection end position.
During the return process:
As the Array empties out from the first to the last index, the return process starts at the first index again.
When a number is "returned," it is placed back into the input Array at the earliest available index.
The return index is advanced.
Neither the selection index nor the return index may pass each other,
except when one reaches the end of the Array and wraps back around to that start.
RandomSelector
Get a specific number from a pool of numbers.
Get the next number in this pool incrementally.
Get the next number in this pool incrementally. Starting at index 0, for example, select each subsequent number as it is available. Do not progress if a number is not available when requested.
The base class for all different sorts of number selection policies.
The
Arrays called out as method parameters is always anArrayof indexes for some other list. The indices in theArrayare always the complete range of 0 tonnumbers. It is recommended to initialize theArraywith the rulearray(number) = number. When they need to be flagged as "invalid" in some way, use some consistent system of negative numbers. (Recommendation: unless doing something fancy, just use -1.)