flow_draw() should only be used in the debugger triggered by a call to flow_run(), or following a call to flow_debug(). d is an active binding to flow_draw(), it means you can just type d (without parentheses) instead of flow_draw().




Returns NULL invisibly (called for side effects)


d was designed to look like the other shortcuts detailed in ?browser, such as f, c etc... It differs however in that it can be overridden. For instance if the function uses a variable d or that a parent environment contains a variable d, flow::d won't be found. In that case you will have to use flow_draw().

If d or flow_draw() are called outside of the debugger they will return NULL silently.