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    1: \ environmental queries
    2: 
    3: \ Copyright (C) 1995,1996,1997,1998 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: \ wordlist constant environment-wordlist
   22: 
   23: Create environment-wordlist ( -- wid ) \ gforth
   24:   \G @i{wid} identifies the word list that is searched by environmental
   25:   \G queries.
   26:   wordlist drop
   27: 
   28: : environment? ( c-addr u -- false / ... true ) \ core environment-query
   29:     \G @i{c-addr, u} specify a counted string. If the string is not
   30:     \G recognised, return a @code{false} flag. Otherwise return a
   31:     \G @code{true} flag and some (string-specific) information about
   32:     \G the queried string.
   33:     environment-wordlist search-wordlist if
   34: 	execute true
   35:     else
   36: 	false
   37:     endif ;
   38: 
   39: : e? name environment? 0= ABORT" environmental dependency not existing" ;
   40: 
   41: : has? name environment? 0= IF false THEN ;
   42: 
   43: : $has? environment? 0= IF false THEN ;
   44: 
   45: environment-wordlist set-current
   46: get-order environment-wordlist swap 1+ set-order
   47: 
   48: \ assumes that chars, cells and doubles use an integral number of aus
   49: 
   50: \ this should be computed in C as CHAR_BITS/sizeof(char),
   51: \ but I don't know any machine with gcc where an au does not have 8 bits.
   52: 8 constant ADDRESS-UNIT-BITS ( -- n ) \ environment
   53: \G Size of one address unit, in bits.
   54: 
   55: 1 ADDRESS-UNIT-BITS chars lshift 1- constant MAX-CHAR ( -- u ) \ environment
   56: \G Maximum value of any character in the character set
   57: 
   58: MAX-CHAR constant /COUNTED-STRING ( -- n ) \ environment
   59: \G Maximum size of a counted string, in characters.
   60: 
   61: ADDRESS-UNIT-BITS cells 2* 2 + constant /HOLD ( -- n ) \ environment
   62: \G Size of the pictured numeric string output buffer, in characters.
   63: 
   64: &84 constant /PAD ( -- n ) \ environment
   65: \G Size of the scratch area pointed to by @code{PAD}, in characters.
   66: 
   67: true constant CORE ( -- f ) \ environment
   68: \G True if the complete core word set is present. Always true for Gforth.
   69: 
   70: true constant CORE-EXT ( -- f ) \ environment
   71: \G True if the complete core extension word set is present. Always true for Gforth.
   72: 
   73: 1 -3 mod 0< constant FLOORED ( -- f ) \ environment
   74: \G True if @code{/} etc. perform floored division
   75: 
   76: 1 ADDRESS-UNIT-BITS cells 1- lshift 1- constant MAX-N ( -- n ) \ environment
   77: \G Largest usable signed integer.
   78: 
   79: -1 constant MAX-U ( -- u ) \ environment
   80: \G Largest usable unsigned integer.
   81: 
   82: -1 MAX-N 2constant MAX-D ( -- d ) \ environment
   83: \G Largest usable signed double.
   84: 
   85: -1. 2constant MAX-UD ( -- ud ) \ environment
   86: \G Largest usable unsigned double.
   87: 
   88: version-string 2constant gforth ( -- c-addr u ) \ gforth-environment
   89: \G Counted string representing a version string for this version of
   90: \G Gforth (for versions>0.3.0).  The version strings of the various
   91: \G versions are guaranteed to be ordered lexicographically.
   92: 
   93: : return-stack-cells ( -- n ) \ environment
   94:     \G Maximum size of the return stack, in cells.
   95:     [ forthstart 6 cells + ] literal @ cell / ;
   96: 
   97: : stack-cells ( -- n ) \ environment
   98:     \G Maximum size of the data stack, in cells.
   99:     [ forthstart 4 cells + ] literal @ cell / ;
  100: 
  101: : floating-stack ( -- n ) \ environment
  102:     \G @var{n} is non-zero, showing that Gforth maintains a separate
  103:     \G floating-point stack of depth @var{n}.
  104:     [ forthstart 5 cells + ] literal @
  105:     [IFDEF] float  float  [ELSE]  [ 1 floats ] Literal [THEN] / ;
  106: 
  107: \ !! max-float
  108: 15 constant #locals \ 1000 64 /
  109:     \ One local can take up to 64 bytes, the size of locals-buffer is 1000
  110: maxvp constant wordlists
  111: 
  112: forth definitions
  113: previous
  114: