watch

The watch statement allows to monitor the value of a variable or an expression. It will be shown in the main window's GUI among parameters at the current position. A watch may optionally be named. Then, it can be used in expressions like a parameter. A named watch may also be specified with the hidden modifier to hide it from the GUI.

Example:

watch score;
watch distance(start, position);
watch direction = atan(vector.y, vector.x);