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Abstractly, the runtime is a bunch of functions from PState to PState, and this means every parse operation involves allocating a new PState object. Effectively, the parser behaves like an inner-loop calling the allocator for PState objects. This has the advantage that all code is inherently thread-safe.
Note: except the implementation currently uses JDOM trees as the Infoset representation, and these are mutated. These would have to be replaced by an inverted child-points-to-parent-only pure-functional Infoset representation.
However, this also limits performance to that of the garbage collector, and parallel performance to the ability of the allocator and garbage collector to run in parallel.
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