Loop

Generalisation of Recurse and StateRecurse

The loop defines some state with an initial value which is maintained at each step of the interpretation.

A is the type of Eff values to interpret, and B is the result of the interpretation (generally an other Eff value)

C is the type of result for "last" actions.

• the interpretation of a Pure value either returns the final result or possibly one more Eff value to interpret

• onEffect interprets one effect and possibly uses the continuation to produce the next value to interpret. If no X can be used to run the continuation we might just output one final B value

• onLastEffect interprets the last effect of an Eff value. The only difference with onEffect is the fact that last actions return Unit values (and not A values)

• onApplicativeEff interprets a list of effects and possibly uses the continuation to get to the next value to interpret. If no interpretation can be done, a B value might be returned

• onLastApplicativeEffect does the same thing for last actions