Code style: module size

[eyelidlessness]

As raised in #345: module size contributes to cognitive load.

• What is a sensible default for the maximum size of a module?
  • Can we determine one that's (mostly) general enough to apply throughout the project?
  • Can we use automation to reduce the cognitive load of mitigating that?
    • What is the best way to determine where to make exceptions?
• How can we best balance the cognitive load of large module size, versus the cognitive load of a large number of sources for cohesive (documentation | data model | runtime behavior and data flow | [anything else that a module conveys])?
• Where we share interfaces with other projects (e.g. JavaRosa's Scenario and XForms DSL): how can we best balance reducing this aspect of cognitive load, while retaining interoperability?