logic control

Rules in KRL can be thought of as the body of an if statement, with the "select when" being the condition.

Rules are used to;

1. modify Picos states by setting entity variables and app variables. 
2. raise and send events with updated attributes.

KRL rule structure;

• "Select when"
  • First control of logic, when this event assures do ....
• "pre block"
  
  • used to make calculations for the if then conditions
• "action block"
  • This block can include an if then statement.
  • if this condition is met do some combination of actions.
  • actions can include sending directives or events, things that have to happen as a result of this event. 

• "post block"

  • This block can be, always, fired, notfired, else.

  • this is where you set entity variables 

-switch

-defaults

-||, ->

-guards