add apply_config in ExprCalcCounter
In order to be able to handle modifications of constants "on the fly", it would be good to expose apply_config()
at the ExprCalcCounter
controller level: this should re-evaluate formula, etc, and re-instantiate constants
.
Remark: today, if a constant is changed, calling the_controller.constants.apply_config(reload=True)
get changes and apply them, but it cannot handle new constants or changes in the expression.
(reported by @berruyer )