# # frame.rb - # $Release Version: 0.9$ # $Revision: 38515 $ # by Keiju ISHITSUKA(Nihon Rational Software Co.,Ltd) # # -- # # # require "e2mmap" module IRB class Frame extend Exception2MessageMapper def_exception :FrameOverflow, "frame overflow" def_exception :FrameUnderflow, "frame underflow" # Default number of stack frames INIT_STACK_TIMES = 3 # Default number of frames offset CALL_STACK_OFFSET = 3 # Creates a new stack frame def initialize @frames = [TOPLEVEL_BINDING] * INIT_STACK_TIMES end # Used by Kernel#set_trace_func to register each event in the call stack def trace_func(event, file, line, id, binding) case event when 'call', 'class' @frames.push binding when 'return', 'end' @frames.pop end end # Returns the +n+ number of frames on the call stack from the last frame # initialized. # # Raises FrameUnderflow if there are no frames in the given stack range. def top(n = 0) bind = @frames[-(n + CALL_STACK_OFFSET)] Fail FrameUnderflow unless bind bind end # Returns the +n+ number of frames on the call stack from the first frame # initialized. # # Raises FrameOverflow if there are no frames in the given stack range. def bottom(n = 0) bind = @frames[n] Fail FrameOverflow unless bind bind end # Convenience method for Frame#bottom def Frame.bottom(n = 0) @backtrace.bottom(n) end # Convenience method for Frame#top def Frame.top(n = 0) @backtrace.top(n) end # Returns the binding context of the caller from the last frame initialized def Frame.sender eval "self", @backtrace.top end @backtrace = Frame.new set_trace_func proc{|event, file, line, id, binding, klass| @backtrace.trace_func(event, file, line, id, binding) } end end