Functions (such as those you add to toolbar buttons or hotkeys) can use the evaluator in a number of ways:

  • The label can be dynamically generated using the @label modifier.
  • The icon can be dynamically modified using the @icon and related modifiers.
  • The button tooltip can be generated using an evaluation expression.
  • Button states like enabled/disabled, hidden/shown and checked/unchecked can be modified using the evaluator.
  • Conditional behavior in buttons using @if and @ifset can be performed using the evaluator.
  • The @eval modifier lets you run a line of evaluator code as part of a function.
  • The return value of an evaluator expression can be inserted into a command line using the {= ... =} code.
  • The evaluator can be used to generate a command line that's then executed as if it were part of the function.