Stop Vector Stack trace

[Hans-Peter Sorge]

    Hi,
        
        $ apl -q
        
        set the stop vector for long running / large data volume
        functions
      when
        a particular situation is met. 
        
        Here grossly simplified ...   
       
             ∇x
        [1] ⍎1/'S∆x←stopper'
      
      [2] stopper:
      
      [3] S∆x←⍳0∇
      
            x
      
      x[2]
      
            →2
      
      Symbol is:
        'stopper' at Symbol.cc:404
      
      *** useless
        apl.lines (no CXXFLAGS=-rdynamic -gdwarf-2)
      
      
      ----------------------------------------
      
      -- Stack
        trace at Symbol.cc:405
      
      ----------------------------------------
      
      0x7fd29aa1030b
        __libc_start_main
      
      0x7fd29aa10248
          
      0x403e50
          main
      
      0x5d7117
           Workspace::immediate_execution(bool)
      
      0x45eeb7
            Command::process_line()
      
      0x45f112
             Command::process_line(UCS_string&, std::ostream*)
      
      0x46172a
              Command::do_APL_expression(UCS_string&)
      
      0x461cb8
               Command::finish_context()
      
      0x5d6eed
                Workspace::pop_SI(char const*)
      
      0x56d633
                 StateIndicator::~StateIndicator()
      
      0x56fb56
                  UserFunction::pop_local_vars() const
      
      0x5bd308
                   UserFunction_header::pop_local_vars() const
      
      0x57b518
                    Symbol::pop()
      
      ========================================
      
      ========================================
      
      
      Best Regards
      Hans-Peter