Re: [Groff] changed .substring

[Bernd Warken]

.substring does not test range violations.  If indexes are out of range
the string is not altered; this is not wanted.

The following behavior is used with other languages:

1) Referring an index before the first or after the last character
should produce an error (>=length or <-length).

.ds s abc
.substring s 3 3      \" should be an error
.substring s -4 -4    \" should be an error

2) If the first argument points to an index after the index retrieved 
from the second argument the result should be the empty string.

.ds s abc
.substring s 2 1      \" s should become empty
.substring s -1 -2    \" s should become empty
.substring s 2 -2     \" s should become empty


Bernd Warken