vm/instructions.rb
# [Operation]
#   Placeholder for a removed opcode
# [Format]
#   \unused
# [Stack Before]
#   * ...
# [Stack After]
#   * ...
# [Description]
#    Raises an assert failure if used.
# [Notes]
#   This opcode is used wherever a previously used opcode has been removed.
#   It ensures that removing an opcode does not change the numbering of
#   succeeding opcodes.
#
#   The same opcode symbol (:unused) and instruction body can be used anywhere
#   an opcode has been removed.
[Operation]
Placeholder for a removed opcode
[Format]
\unused
[Stack Before]

[Stack After]

[Description]
Raises an assert failure if used.
[Notes]
This opcode is used wherever a previously used opcode has been removed.
It ensures that removing an opcode does not change the numbering of
succeeding opcodes.

The same opcode symbol (:unused) and instruction body can be used anywhere
an opcode has been removed.
[ Operation ] Placeholder for a removed opcode [ Format ] \ unused [ Stack Before ] [ Stack After ] [ Description ] Raises an assert failure if used . [ Notes ] This opcode is used wherever a previously used opcode has been removed . It ensures that removing an opcode does not change the numbering of succeeding opcodes . The same opcode symbol ( : unused ) and instruction body can be used anywhere an opcode has been removed .
def unused
    <<-CODE
    sassert(0 && "deprecated opcode was encountered!");
    CODE
  end
def unused <<-CODE 
    sassert(0 && "deprecated opcode was encountered!");
     CODE end
[Operation]
Placeholder for a removed opcode
[Format]
\unused
[Stack Before]
 ...
[Stack After]
 ...
[Description]
Raises an assert failure if used.
[ Operation ] Placeholder for a removed opcode [ Format ] \ unused [ Stack Before ] ... [ Stack After ] ... [ Description ] Raises an assert failure if used .