Journeyman is my undergraduate COMP4560 project, with the aim to create an easy-to-use eDSL that can be used to create and analyse arbitrary tournament structures; such as "common" ones like Single or Double Elimination, or compositions like N groups of Single Elimination.

• Your entrypoint to the eDSL should be the Tourney.Algebra module.
• Your entrypoint to exploring what's possible with Journeyman should be the journeyman-ui executable that comes bundled with this package. It uses an extensible tournament UI defined in Tourney.UI.Main, but all you as a user needs to do is extend the list of known tournaments you pass to createTourneyUI with a tournament you create. For an example of how to do this, see the executable in app/Main.hs .
• To create a special-purpose tournament VM, for instance, to simulate a tournament structure under different conditions, see the Tourney.VM module. This module also provides functionality for gauging the performance of a tournament structure by simulating it over a given Elo rating distribution.
• Functions dealing merely with sorting networks or point-award based sorting networks such as those supported by Journeyman can be found in Tourney.SortingNetwork

Some example tournament structures are provided under the Tourney.Format.* module. Navigating to these and familiarising yourself with the source code via the Source links may be quite helpful in gaining an intuition for how Journeyman works and what its capabilities are.

Analogies between sorting networks and tournaments

A key observation of made at the outset of this project is that there is an analogy between sorting networks and many tournament structures. Here, a sorting network refers to a fixed schedule or "network" of comparisons between a fixed set of objects. Each comparison has a fixed coordinate or wire in the network, and results in either the objects staying in the same position as they were (if they were already in order with respect to eachother), or they exchange places if not.

I call a sorting network "partial" if it does not determine a complete ordering among players; for instance if out of 16 elements it determines the greatest 8 in order, but leaves the remaining 8 in two buckets of 4 items where only the order of the buckets is known.

A Single Elimination tournament has a partial sorting network construction. This is because at each round we can draw matches between the winners of the previous round only; that is, those players that now occupy the "high" position of the sorting network, after a single step of the network. At the same time, the losers of each round are simply not given any further comparisons (i.e., matches) from the point that they were eliminated, and so remain ranked at whatever point they were eliminated.

Similarly, we can also construct a Double-Elimination tournament by sorting network, by creating matches between those players that lost in first round of the "upper" bracket, and then alternating rounds that either accept new losers from the previous upper bracket round into new matches in the lower bracket, or that play off players who are in the lower bracket. Not all tournaments are sorting networks however. For instance, a round robin tournament has no sorting network equivalent, even though it has a fully-determined schedule for \(n\) players. To get around this, we define a special primitive that allows the method by which players exchange positions to be redefined; for instance, in a round robin, the method is that players shall accumulate points by winning matches, and then be ordered from most points to least.