Notes and ideas about effects

effects.md

Effects

• Ordered

  The ordering of two operations is significant (outside of data dependencies). For example, writing to a file and removing a file are order-dependent.

• Mutating

  An operation is observable to non-deterministic operations. Mutations are non-reversible after a non-deterministic operation depends upon the mutation.

• Non-deterministic

  The result of an operation depends upon mutations of other operations.

• Flow-controlling

  An operation may change how a program is executed. Process and thread forks, exceptions, coroutines, signals, and laziness fall into this category.

• Diverging

  An operation may not return a value, despite its type claiming to return a value. An infinite loop is the divergent.

• Transactional

  Like mutation, but observing operations are reversible.