main:
    /^\s*\Z/
    | input_line
    | <error>

EOL:
    /\s*\Z/

input_line:
    opcode_8031
    | <error>

#
#  The opcode code list.  Reverse these two to fix, or RET/RETI ordering to break.
#

opcode_8031:
    opcode_ret EOL
    | opcode_reti EOL

opcode_ret:
    OP_RET
    { print "Got ret!\n" }

opcode_reti:
    OP_RETI
    { print "Got reti!\n" }

#
#  8031 opcodes
#
OP_RET:     'ret'
OP_RETI:    'reti'