(      Title:  Measured strings null termination
        File:  mstrings-0end.fs
      Author:  David N. Williams
     License:  LGPL
     Version:  0.8.4
   Test file:  mstrings-test.fs
  Change log:  mstrings.log
     Revised:  August 26, 2008

Copyright [C] 2002, 2007, 2008 David N. Williams

This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or at your option any later version.

This software is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU Lesser General Public License for more details.

If you take advantage of the option in the LGPL to put a
particular version of this library under the GPL, the author[s]
would regard it as polite if you would put any direct
modifications under the LGPL as well, and include a copy of this
request near the beginning of the modified library source.  A
"direct modification" is one that enhances or extends the
library in line with its original concept, as opposed to
developing a distinct application or library which might use it.

This is a library in the mstrings collection.  It is mostly ANS
Forth compatible up to case dependence, [UNDEFINED], and
REQUIRED.

The code is intended to be character clean.

Please see the file mstrings.txt for terminology and more
detailed word specifications.
)
decimal

s" mstrings-srep.fs" required


\ *** NULL TERMINATION WORDS

\   (null-m+)  null-m+  null-m+,


\ *** UTILITY WORDS

\ DEBUGGING
\ : .#  ( n -- )  cr ." #" . cr ;

[UNDEFINED] chars+ [IF]
: chars+  ( x n -- x+c[n] )  chars + ; [THEN]


\ *** DEFINITIONS
(
These words append a null character to an mstring, without
changing its count.  Assuming no other embedded nulls, the
resulting string body is a C string when the C size of a char is
the same as 1 CHARS.

The action of NULL-M+, agrees with its name when the next
available slot in data space is contiguous with the end of an
mstring, and that is not checked.
)

: (null-m+)  ( m -- )  mcount chars+ 0 swap c! ;

: null-m+  ( mbuf /mbuf -- flag )
  over @ /m u>
  IF mcount chars+ 0 swap c! true ELSE drop false THEN ;

: null-m+,  ( -- )  0 c, ;