New Data Matching Behaviour in 0.9.0005 and later

I think that this infomation could be useful. This discussion comes from here.

David says:

Data Matching has changed because (A) there was a bug under certain conditions and (B) I wanted to make it more economical with regards to data path growth. The new logic is roughly as follows:

First a master input parameter is identified. At the moment, it is the parameter with the longest path length. The amount of paths doesn't matter. Input parameters that have Tree access are never Master parameters (unless absolutely no other parameter is available) and List parameters have lower priority than Item parameters. In future versions it will probably become possible to assign a custom input as master. This however is an expert user function and I want to post-pone adding it as long as possible in order for the default behaviour to be tested and improved.

If all input parameters are list parameters, output paths are no longer grown. I.e. The Reverse List component should output the exact same data tree structure as it gets.

The master parameter might not be the parameter with the most branches. It is therefore possible that we run out of defined paths before the component is done computing. If this happens, the last index of the last available path in the master parameter is incremented on each iteration:

Input A = {0;0} {0;1} {0;2}
Input B = {0;1;0}
Output C = {0;1;0} {0;1;1} {0;1;2}

A has a maximum path length of 2, B has a maximum path length of 3, B is therefore the Master parameter. However we need three unique output paths since A provides three paths, so {0;1;1} and {0;1;2} are made up on the spot.

It is also no longer possible to apply 'Shortest List' and 'Cross Reference' options to components. Old components that had these options set still work like they did before, but that should be considered legacy support. Instead, there are now three components in the Sets tab, List panel called 'Cross Reference', 'Short List', 'Long List' that basically provide the old functionality with a lot of additional flexibility and options.