A break-point always stops the current evaluation and calls the debugging callback.

A break-point is represented by the debugger::BreakPoint type, which is an enum with the following variants.

BreakPoint variantNot available underDescription
AtPosition { source, pos, enabled }no_positionbreaks at the specified position in the specified source (empty if none);
if pos is at beginning of line, breaks anywhere on the line
AtFunctionName { name, enabled }breaks when a function matching the specified name is called (can be operator)
AtFunctionCall { name, args, enabled }breaks when a function matching the specified name (can be operator) and the specified number of arguments is called
AtProperty { name, enabled }no_objectbreaks at the specified property access

Access Break-Points

The following debugger::Debugger methods allow access to break-points for manipulation.

MethodReturn typeDescription
break_points&[BreakPoint]returns a slice of all BreakPoint’s
break_points_mut&mut Vec<BreakPoint>returns a mutable reference to all BreakPoint’s


use rhai::debugger::*;

let debugger = &mut context.global_runtime_state_mut().debugger_mut();

// Get number of break-points.
let num_break_points = debugger.break_points().len();

// Add a new break-point on calls to 'foo(_, _, _)'
    BreakPoint::AtFunctionCall { name: "foo".into(), args: 3 }

// Display all break-points
for bp in debugger.break_points().iter() {

// Clear all break-points