1# word boundaries (ick)
2[[:<:]]a  &         a         a
3[[:<:]]a  &         ba
4[[:<:]]a  &         -a        a
5a[[:>:]]  &         a         a
6a[[:>:]]  &         ab
7a[[:>:]]  &         a-        a
8[[:<:]]a.c[[:>:]]   &         axcd-dayc-dazce-abc abc
9[[:<:]]a.c[[:>:]]   &         axcd-dayc-dazce-abc-q         abc
10[[:<:]]a.c[[:>:]]   &         axc-dayc-dazce-abc  axc
11[[:<:]]b.c[[:>:]]   &         a_bxc-byc_d-bzc-q   bzc
12[[:<:]].x..[[:>:]]  &         y_xa_-_xb_y-_xc_-axdc         _xc_
13[[:<:]]a_b[[:>:]]   &         x_a_b
14