=== test 0: input="[1 "abc" ===
    iter=0 off=0 len=1 tok=6 nbracket=0 nbrace=0 char='[' off_after=1 (delta=1)
    iter=1 off=1 len=1 tok=2 nbracket=1 nbrace=0 char='1' off_after=2 (delta=1)
    iter=2 off=3 len=1 tok=1 nbracket=1 nbrace=0 char='"' off_after=4 (delta=1)
    iter=3 off=4 len=3 tok=2 nbracket=1 nbrace=0 char='a' off_after=7 (delta=3)
    iter=4 off=7 len=0 tok=0 nbracket=1 nbrace=0 char='-> rc=22 len=-999 iters=4

=== test 1: input="["abc" ===
    iter=0 off=0 len=1 tok=6 nbracket=0 nbrace=0 char='[' off_after=1 (delta=1)
    iter=1 off=1 len=1 tok=1 nbracket=1 nbrace=0 char='"' off_after=2 (delta=1)
    iter=2 off=2 len=3 tok=2 nbracket=1 nbrace=0 char='a' off_after=5 (delta=3)
    iter=3 off=5 len=0 tok=0 nbracket=1 nbrace=0 char='-> rc=22 len=-999 iters=3

=== test 2: input="{"abc" ===
    iter=0 off=0 len=1 tok=4 nbracket=0 nbrace=0 char='{' off_after=1 (delta=1)
    iter=1 off=1 len=1 tok=1 nbracket=0 nbrace=1 char='"' off_after=2 (delta=1)
    iter=2 off=2 len=3 tok=2 nbracket=0 nbrace=1 char='a' off_after=5 (delta=3)
    iter=3 off=5 len=0 tok=0 nbracket=0 nbrace=1 char='-> rc=22 len=-999 iters=3

=== test 3: input="[["abc" ===
    iter=0 off=0 len=1 tok=6 nbracket=0 nbrace=0 char='[' off_after=1 (delta=1)
    iter=1 off=1 len=1 tok=6 nbracket=1 nbrace=0 char='[' off_after=2 (delta=1)
    iter=2 off=2 len=1 tok=1 nbracket=2 nbrace=0 char='"' off_after=3 (delta=1)
    iter=3 off=3 len=3 tok=2 nbracket=2 nbrace=0 char='a' off_after=6 (delta=3)
    iter=4 off=6 len=0 tok=0 nbracket=2 nbrace=0 char='-> rc=22 len=-999 iters=4

=== test 4: input="[abcdef"abc" ===
    iter=0 off=0 len=1 tok=6 nbracket=0 nbrace=0 char='[' off_after=1 (delta=1)
    iter=1 off=1 len=6 tok=2 nbracket=1 nbrace=0 char='a' off_after=7 (delta=6)
    iter=2 off=7 len=6 tok=1 nbracket=1 nbrace=0 char='"' off_after=13 (delta=6)
    iter=3 off=14 len=1 tok=7 nbracket=1 nbrace=0 char=']' off_after=15 (delta=1)
-> rc=0 len=15 iters=4

=== test 5: input="[ ]" ===
    iter=0 off=0 len=1 tok=6 nbracket=0 nbrace=0 char='[' off_after=1 (delta=1)
    iter=1 off=2 len=1 tok=7 nbracket=1 nbrace=0 char=']' off_after=3 (delta=1)
-> rc=0 len=3 iters=2

=== test 6: input="[1 2 3]" ===
    iter=0 off=0 len=1 tok=6 nbracket=0 nbrace=0 char='[' off_after=1 (delta=1)
    iter=1 off=1 len=1 tok=2 nbracket=1 nbrace=0 char='1' off_after=2 (delta=1)
    iter=2 off=3 len=1 tok=2 nbracket=1 nbrace=0 char='2' off_after=4 (delta=1)
    iter=3 off=5 len=1 tok=2 nbracket=1 nbrace=0 char='3' off_after=6 (delta=1)
    iter=4 off=6 len=1 tok=7 nbracket=1 nbrace=0 char=']' off_after=7 (delta=1)
-> rc=0 len=7 iters=5

=== test 7: input=""abc" ===
    iter=0 off=0 len=0 tok=1 nbracket=0 nbrace=0 char='"' off_after=0 (delta=0)
-> rc=0 len=0 iters=1