52
54
string is "abyz", the lack of "d" means that matching doesn't ever start, and
53
55
the callout is never reached. However, with "abyd", though the result is still
54
56
no match, the callout is obeyed.
60
if the subject is not long enough, or, for unanchored patterns, if it has
57
69
.SH "THE CALLOUT INTERFACE"