$ perl -e 'print(ref(\pos) . "\n");'
LVALUE

$ perl -e 'use B; print(ref(B::svref_2object(\substr "foo",1)) . "\n");'
B::PVLV

$ perl -MO=Terse -ce '$v=2; $v=2.3; $v="txt"; print index($v,"x",0);'
LISTOP (0x7d61afc0) leave [1]
    OP (0x7df6e560) enter
    COP (0x8b34b340) nextstate
    BINOP (0x7d61aa60) sassign
        SVOP (0x7d61a9c0) const  IV (0x85306280) 2
        UNOP (0x7d61af20) null [15]
            SVOP (0x7d61afe0) gvsv  GV (0x86712440) *v
    COP (0x8b34b380) nextstate
    BINOP (0x7d61afa0) sassign
        SVOP (0x7cd4e6c0) const  NV (0x86712460) 2.3
        UNOP (0x7d61af60) null [15]
            SVOP (0x7d61ae60) gvsv  GV (0x86712440) *v
    COP (0x7f6ffe40) nextstate
    BINOP (0x7df6edc0) sassign
        SVOP (0x7df6ee60) const  PV (0x86712510) "txt"
        UNOP (0x7df6ed00) null [15]
            SVOP (0x7df6eca0) gvsv  GV (0x86712440) *v
    COP (0x7f6fff80) nextstate
    LISTOP (0x7df6ef60) print
        OP (0x7df6ef20) pushmark
        LISTOP (0x7d61ac80) index [1]
            OP (0x7df6ed60) null [3]
            UNOP (0x7df6eee0) null [15]
                SVOP (0x7df6eda0) gvsv  GV (0x86712440) *v
            SVOP (0x7d61ad00) const  GV (0x867124b0) "x"
            SVOP (0x7df6eec0) const  IV (0x86712470) 0
-e syntax OK

$ perl -MO=Terse -ce '@a = qw(1 two 3);foreach (@a) {print "$_\n";}'
LISTOP (0x8b2d0ec0) leave [1]
    OP (0x81b42e00) enter
    COP (0x8945b100) nextstate
    BINOP (0x818e7080) aassign [2]
        UNOP (0x83c67f60) null [142]
            OP (0x83c67fe0) pushmark
            SVOP (0x83c67f80) const  PV (0x888cf470) "1"
            SVOP (0x83c67ca0) const  PV (0x888cf510) "two"
            SVOP (0x83c67fa0) const  PV (0x888cf4b0) "3"
        UNOP (0x83c67ce0) null [142]
            OP (0x8a367fa0) pushmark
            UNOP (0x83c67f40) rv2av [1]
                SVOP (0x7e65a4c0) gv  GV (0x888cf440) *a
    COP (0x88486f80) nextstate
    BINOP (0x87348f00) leaveloop
        LOOP (0x88486ec0) enteriter
            OP (0x87348f80) null [3]
            UNOP (0x873489a0) null [142]
                OP (0x87348ee0) pushmark
                UNOP (0x87348a20) rv2av [3]
                    SVOP (0x87348680) gv  GV (0x888cf440) *a
            SVOP (0x87348fc0) gv  GV (0x7f67f170) *_
        UNOP (0x87348d80) null
            LOGOP (0x87348f60) and
                OP (0x87348fa0) iter
                LISTOP (0x87348e40) lineseq
                    COP (0x8945b140) nextstate
                    LISTOP (0x87348c20) print
                        OP (0x87348d20) pushmark
                        UNOP (0x87348f40) null [67]
                            OP (0x87348e20) null [3]
                            BINOP (0x83c67c60) concat [4]
                                UNOP (0x83c679c0) null [15]
                                    SVOP (0x83c67f00) gvsv  GV (0x7f67f170) *_
                                SVOP (0x87348da0) const  PV (0x888cf490) "\n"
                    OP (0x87348e80) unstack
-e syntax OK