EffectElaborator

A compiler phase which partitions a query for execution which may invoke multiple effect handlers.

This phase transforms the input query by assigning subtrees to effect handlers as specified by the supplied emapping.

The mapping has Type and field name pairs as keys and effect handlers as values. When the traversal of the input query visits a Select node with type Type.field name it will replace the Select with an Effect node comprising,

1. the effect handler which will be responsible for running the effect and evaluating the subquery against its result. 2. the subquery which will be evaluated by the effect handler.