The following words are useful for growable memory buffers. One can
alternatively use $trings (see $tring words), and the differences
are: When the used memory in the buffer shrinks, $trings may resize
the buffer, while adjust-buffer does not, which may be
preferable for a buffer that is reused all the time. However, $strings
have one cell less memory overhead, and for longer-term storage the
shrinking may be worthwhile.
buffer% ( u1 u2 – ) gforth-experimental “buffer%”
u1 is the alignment and u2 is the size of a buffer descriptor.
init-buffer ( addr – ) gforth-experimental “init-buffer”
adjust-buffer ( u addr – ) gforth-experimental “adjust-buffer”
Adjust buffer% at addr to length u. This may grow the allocated area, but never shrinks it.
You can get the current address and length of such a buffer with
2@.
Typical usage:
create mybuf buffer% %allot mybuf init-buffer s" frobnicate" mybuf adjust-buffer mybuf 2@ move mybuf 2@ type s" foo" mybuf adjust-buffer mybuf 2@ move mybuf 2@ type