1: \ VARS.FS Kernal variables
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: hex \ everything now hex! 11may93jaw
22:
23: \ important constants 17dec92py
24:
25: \ dpANS6 (sect 3.1.3.1) says
26: \ "a true flag ... [is] a single-cell value with all bits set"
27: \ better definition: 0 0= constant true ( no dependence on 2's compl)
28: -1 Constant true ( -- f ) \ core-ext
29: \G CONSTANT: f is a cell with all bits set.
30: \ see starts looking for primitives after this word!
31:
32: 0 Constant false ( -- f ) \ core-ext
33: \G CONSTANT: f is a cell with all bits clear.
34:
35: 1 cells Constant cell ( -- u ) \ gforth
36: 1 floats Constant float ( -- u ) \ gforth
37:
38: 20 Constant bl ( -- c-char ) \ core
39: \G c-char is the character value for a space.
40: \ used by docon:, must be constant
41:
42: FF Constant /line
43:
44: 40 Constant c/l
45: 10 Constant l/s
46: 400 Constant chars/block
47:
48: $20 8 2* cells + 2 + cell+ constant word-pno-size ( -- u )
49: create holdbuf word-pno-size chars allot
50: holdbuf word-pno-size chars + aconstant holdbuf-end
51: avariable holdptr holdbuf-end holdptr a!
52: avariable holdend holdbuf-end holdend a!
53:
54: 84 constant pad-minsize ( -- u )
55:
56:
57: \ that's enough so long
58:
59: \ User variables 13feb93py
60:
61: \ initialized by COLD
62:
63: Create main-task has? OS [IF] 100 [ELSE] 40 [THEN] cells allot
64:
65: \ set user-pointer from cross-compiler right
66: main-task
67: UNLOCK tup ! LOCK
68:
69: Variable udp \ user area size? -anton
70:
71: AUser next-task main-task next-task !
72: AUser prev-task main-task prev-task !
73: AUser save-task 0 save-task !
74: AUser sp0 ( -- a-addr ) \ gforth
75: \G USER VARIABLE: Initial value of the data stack pointer.
76: \ sp0 is used by douser:, must be user
77: ' sp0 Alias s0 ( -- a-addr ) \ gforth
78: \G OBSOLETE alias of @code{sp0}
79:
80: AUser rp0 ( -- a-addr ) \ gforth
81: \G USER VARIABLE: Initial value of the return stack pointer.
82: ' rp0 Alias r0 ( -- a-addr ) \ gforth
83: \G OBSOLETE alias of @code{rp0}
84:
85: AUser fp0 ( -- a-addr ) \ gforth
86: \G USER VARIABLE: Initial value of the floating-point stack pointer.
87: \ no f0, because this leads to unexpected results when using hex
88:
89: AUser lp0 ( -- a-addr ) \ gforth
90: \G USER VARIABLE: Initial value of the locals stack pointer.
91: ' lp0 Alias l0 ( -- a-addr ) \ gforth
92: \G OBSOLETE alias of @code{lp0}
93:
94: AUser handler \ pointer to last throw frame
95: AUser backtrace-empty \ true if the next THROW should store a backtrace
96: \ AUser output
97: \ AUser input
98:
99: AUser errorhandler
100:
101: AUser "error 0 "error !
102:
103: [IFUNDEF] #tib \ in ec-Version we may define this ourself
104: User tibstack \ saves >tib in execute
105: User >tib \ pointer to terminal input buffer
106: User #tib ( -- a-addr ) \ core-ext
107: \G USER VARIABLE: a-addr is the address of a cell containing
108: \G the number of characters in the terminal input buffer.
109: \G OBSOLESCENT: @code{source} superceeds the function of this word.
110:
111: User >in ( -- a-addr ) \ core
112: \G USER VARIABLE: a-addr is the address of a cell containing the
113: \G char offset from the start of the terminal input buffer to the
114: \G start of the parse area
115: 0 >in ! \ char number currently processed in tib
116: [THEN]
117: has? file [IF]
118: User blk ( -- a-addr ) \ block
119: \G USER VARIABLE: a-addr is the address of a cell containing zero
120: \G (in which case the input source is not a block and can be identified
121: \G by @code{source-id}) or the number of the block currently being
122: \G interpreted. A Standard program should not alter @code{blk} directly.
123: 0 blk !
124:
125: User loadfile 0 loadfile !
126:
127: User loadfilename# 0 loadfilename# !
128:
129: User loadline \ number of the currently interpreted
130: \ (in TIB) line if the interpretation
131: \ is in a textfile
132: \ the first line is 1
133:
134: 2User linestart \ starting file postition of
135: \ the current interpreted line (in TIB)
136: [THEN]
137:
138: User base ( -- a-addr ) \ core
139: \G USER VARIABLE: a-addr is the address of a cell that stores the
140: \G number base used by default for number conversion during input and output.
141: A base !
142: User dpl -1 dpl !
143:
144: User state ( -- a-addr ) \ core,tools-ext
145: \G Recommended reading: @cite{@code{State}-smartness--Why it is evil
146: \G and how to exorcise it},
147: \G @url{http://www.complang.tuwien.ac.at/papers/ertl98.ps.gz}; short
148: \G version: Don't use @code{state}! @xref{Interpretation and
149: \G Compilation Semantics} for an alternative. USER VARIABLE: a-addr
150: \G is the address of a cell containing the compilation state flag. 0
151: \G => interpreting, -1 => compiling. A program shall not directly
152: \G alter the value of @code{state}. The following Standard words
153: \G alter the value in @code{state}: @code{:} (colon) @code{;}
154: \G (semicolon) @code{abort} @code{quit} @code{:noname} @code{[}
155: \G (left-bracket) @code{]} (right-bracket) @code{;code}
156: 0 state !
157:
158: AUser normal-dp \ the usual dictionary pointer
159: AUser dpp normal-dp dpp !
160: \ the pointer to the current dictionary pointer
161: \ ist reset to normal-dp on (doerror)
162: \ (i.e. any throw caught by quit)
163: AUser LastCFA
164: AUser Last
165:
166: has? glocals [IF]
167: User locals-size \ this is the current size of the locals stack
168: \ frame of the current word
169: [THEN]
170:
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