Module refine 

Adaptive refinement: something built at a resolution — samples along a curve, cells across a face, stations along a blend — built again finer until what it measures of itself is good enough.

The resolution is a free choice; whether the result at one is good enough is the caller’s measurement, made in step. The solver promises that every step is taken from the resolution the one before asked for, at most most of them, and says which way it ended: with the result a step accepted (Refined::Done), or out of steps with the resolution the last one asked for, never accepted (Refined::Exhausted). A caller that has to stop at a coarse result says so by building it from the exhausted resolution; one that must not, errs.

Enums

Refine

What one step made of its resolution.

Refined

How a refinement ended.

Functions

refine

Takes step from start, then from each resolution it asks for, at most most times, until one is Refine::Done. step may keep state of its own (a measure of the step before, to tell whether refining still helps), since every step is taken once, in order.