Schemes for Indirect Control

There are two fundamental approaches to indirect control in code.¹

In an open approach, we can change the behavior of dereferencing code by conveying different values. The decision-making mechanism must be unordered. Typically, this is implemented in code using a data structure with a distinct set of keys, i.e. a lookup table.

In a closed approach, we can only change the decision-making process by changing the underlying code. A conditional, e.g. an expression that uses an if/elif/else or match/case form in Python, is closed. It is ordered, and if predicates aren’t disjoint, order matters.

While an open table conveys values, a conditional decides based on values. For a table to be useful, it must avoid conflicts. Conditionals avoid conflicts by making explicit, fixed decisions. An open approach must avoid conflicts in a dynamic way.

Consider all the kinds of tricks we use to try to force ourselves to work when we’re tired or distracted:

• Willpower: Tell yourself, “Don’t give in to that,” or, “Keep on trying.”
• Activity: Move around. Exercise. Inhale. Shout.
• Expression: Set jaw. Stiffen upper lip. Furrow brow.
• Chemistry: Take coffee, amphetamines, or other brain-affecting drugs.
• Emotion: “If I win, there’s much to gain, but more to lose if I fail!”
• Attachment: Imagine admiration if you succeed – or disapproval if you fail – especially from those to whom you are attached.

So many schemes for self-control! How do we choose which ones to use? There isn’t any easy way. Self-discipline takes years to learn; it grows inside us stage by stage.