class IRB::WorkSpace

def evaluate(context, statements, file = nil, line = nil)

See +lib/tracer.rb+ for more information.

output the exact lines of code are being executed in chronological order.
Evaluate the context of this workspace and use the Tracer library to 
def evaluate(context, statements, file = nil, line = nil)
  if context.use_tracer? && file != nil && line != nil
    Tracer.on
    begin
      __evaluate__(statements, file, line)
    ensure
      Tracer.off
    end
  else
    __evaluate__(statements, file || __FILE__, line || __LINE__)
  end
end