version 1.1, 1994/02/11 16:30:46
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version 1.21, 2000/08/09 20:04:05
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\ ENVIRON.FS Answer environmental queries 20may93jaw |
\ environmental queries |
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\ May be cross-compiled |
\ Copyright (C) 1995,1996,1997,1998 Free Software Foundation, Inc. |
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\ This file is part of Gforth. |
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AVARIABLE EnvLink 0 EnvLink ! |
\ Gforth is free software; you can redistribute it and/or |
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\ modify it under the terms of the GNU General Public License |
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\ as published by the Free Software Foundation; either version 2 |
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\ of the License, or (at your option) any later version. |
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: (env) |
\ This program is distributed in the hope that it will be useful, |
EnvLink linked |
\ but WITHOUT ANY WARRANTY; without even the implied warranty of |
dup c, here over chars allot swap move align |
\ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
, ; |
\ GNU General Public License for more details. |
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: (2env) |
\ You should have received a copy of the GNU General Public License |
EnvLink linked |
\ along with this program; if not, write to the Free Software |
dup $80 or |
\ Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. |
c, here over chars allot swap move align |
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, , ; |
\ wordlist constant environment-wordlist |
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: env" ( n -- ) |
Create environment-wordlist ( -- wid ) \ gforth |
State @ |
\G @i{wid} identifies the word list that is searched by environmental |
IF postpone S" postpone (env) |
\G queries. |
ELSE [char] " parse (env) THEN ; immediate |
wordlist drop |
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: 2env" ( d -- ) |
: environment? ( c-addr u -- false / ... true ) \ core environment-query |
State @ |
\G @i{c-addr, u} specify a counted string. If the string is not |
IF postpone S" postpone (2env) |
\G recognised, return a @code{false} flag. Otherwise return a |
ELSE [char] " parse (2env) THEN ; immediate |
\G @code{true} flag and some (string-specific) information about |
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\G the queried string. |
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environment-wordlist search-wordlist if |
: environment? EnvLink |
execute true |
BEGIN @ dup |
else |
WHILE dup cell+ count $1f and |
false |
4 pick 4 pick compare 0= |
endif ; |
IF nip nip cell+ count dup -rot |
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$1f and + aligned |
: e? name environment? 0= ABORT" environmental dependency not existing" ; |
swap $80 and IF 2@ ELSE @ THEN |
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EXIT |
: has? name environment? 0= IF false THEN ; |
THEN |
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REPEAT |
: $has? environment? 0= IF false THEN ; |
drop 2drop false ; |
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environment-wordlist set-current |
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get-order environment-wordlist swap 1+ set-order |
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\ assumes that chars, cells and doubles use an integral number of aus |
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\ this should be computed in C as CHAR_BITS/sizeof(char), |
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\ but I don't know any machine with gcc where an au does not have 8 bits. |
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8 constant ADDRESS-UNIT-BITS ( -- n ) \ environment |
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\G Size of one address unit, in bits. |
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1 ADDRESS-UNIT-BITS chars lshift 1- constant MAX-CHAR ( -- u ) \ environment |
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\G Maximum value of any character in the character set |
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MAX-CHAR constant /COUNTED-STRING ( -- n ) \ environment |
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\G Maximum size of a counted string, in characters. |
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ADDRESS-UNIT-BITS cells 2* 2 + constant /HOLD ( -- n ) \ environment |
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\G Size of the pictured numeric string output buffer, in characters. |
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&84 constant /PAD ( -- n ) \ environment |
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\G Size of the scratch area pointed to by @code{PAD}, in characters. |
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true constant CORE ( -- f ) \ environment |
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\G True if the complete core word set is present. Always true for Gforth. |
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true constant CORE-EXT ( -- f ) \ environment |
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\G True if the complete core extension word set is present. Always true for Gforth. |
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1 -3 mod 0< constant FLOORED ( -- f ) \ environment |
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\G True if @code{/} etc. perform floored division |
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1 ADDRESS-UNIT-BITS cells 1- lshift 1- constant MAX-N ( -- n ) \ environment |
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\G Largest usable signed integer. |
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-1 constant MAX-U ( -- u ) \ environment |
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\G Largest usable unsigned integer. |
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-1 MAX-N 2constant MAX-D ( -- d ) \ environment |
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\G Largest usable signed double. |
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-1. 2constant MAX-UD ( -- ud ) \ environment |
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\G Largest usable unsigned double. |
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version-string 2constant gforth ( -- c-addr u ) \ gforth-environment |
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\G Counted string representing a version string for this version of Gforth |
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\G (for versions>0.3.0). |
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\ the version strings of the various versions are guaranteed to be |
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\ sorted lexicographically |
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: return-stack-cells ( -- n ) \ environment |
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\G Maximum size of the return stack, in cells. |
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[ forthstart 6 cells + ] literal @ cell / ; |
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: stack-cells ( -- n ) \ environment |
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\G Maximum size of the data stack, in cells. |
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[ forthstart 4 cells + ] literal @ cell / ; |
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: floating-stack ( -- n ) \ environment |
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\G @var{n} is non-zero, showing that Gforth maintains a separate |
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\G floating-point stack of depth @var{n}. |
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[ forthstart 5 cells + ] literal @ |
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[IFDEF] float float [ELSE] [ 1 floats ] Literal [THEN] / ; |
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\ !! max-float |
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15 constant #locals \ 1000 64 / |
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\ One local can take up to 64 bytes, the size of locals-buffer is 1000 |
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maxvp constant wordlists |
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forth definitions |
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previous |
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