File:  [gforth] / gforth / growable.fs
Revision 1.1: download - view: text, annotated - select for diffs
Sat Mar 11 17:49:44 2000 UTC (19 years, 7 months ago) by anton
Branches: MAIN
CVS tags: HEAD
added growable.fs (but not to Makefile)

    1: \ growable buffers/array
    2: 
    3: \ Copyright (C) 2000 Free Software Foundation, Inc.
    4: 
    5: \ This file is part of Gforth.
    6: 
    7: \ Gforth is free software; you can redistribute it and/or
    8: \ modify it under the terms of the GNU General Public License
    9: \ as published by the Free Software Foundation; either version 2
   10: \ of the License, or (at your option) any later version.
   11: 
   12: \ This program is distributed in the hope that it will be useful,
   13: \ but WITHOUT ANY WARRANTY; without even the implied warranty of
   14: \ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   15: \ GNU General Public License for more details.
   16: 
   17: \ You should have received a copy of the GNU General Public License
   18: \ along with this program; if not, write to the Free Software
   19: \ Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
   20: 
   21: struct
   22:     cell% field growable-address1
   23:     cell% field growable-size
   24: end-struct growable%
   25: 
   26: : init-growable ( growable -- )
   27:     0 over growable-address1 !
   28:     1 cells swap growable-size ! ;
   29: 
   30: : grow-to ( u growable -- )
   31:     \ grow growable to at least u aus
   32:     dup >r growable-size @ begin
   33: 	2dup u> while
   34: 	2* repeat
   35:     nip r@ growable-address1 @ over resize throw
   36:     \ !! assumptions: resize with current address 0 is allocate;
   37:     \ resizing to the current size is cheap
   38:     r@ growable-address1 !
   39:     r> growable-size ! ;
   40: 
   41: : growable-addr ( offset growable -- address )
   42:     \ address at offset within growable
   43:     growable-address1 @ + ;
   44: 
   45: : fit-growable ( offset usize growable -- address )
   46:     \ address is at offset within growable; growable becomes large
   47:     \ enough to have an object of size usize there
   48:     >r over + r@ grow-to
   49:     r> growable-addr ;
   50: 
   51: false [if] \ test code
   52: 
   53: growable% %allot constant x
   54: x init-growable
   55: x growable-size ?
   56: 10 x grow-to
   57: x growable-size ?
   58: 4 x growable-addr hex.
   59: 12 8 x fit-growable hex.
   60: x growable-size ?
   61: .s
   62: 
   63: [then]
   64: 

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