1: \ VARS.FS Kernal variables
2:
3: \ Copyright (C) 1995,1996,1997,1998,2000,2003 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., 59 Temple Place, Suite 330, Boston, MA 02111, 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 @code{Constant} -- @i{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 @code{Constant} -- @i{f} is a cell with all bits clear.
34:
35: [IFUNDEF] cell
36: 1 cells Constant cell ( -- u ) \ gforth
37: \G @code{Constant} -- @code{1 cells}
38: [THEN]
39:
40: has? floating [IF]
41: 1 floats Constant float ( -- u ) \ gforth
42: \G @code{Constant} -- the number of address units corresponding to a floating-point number.
43: [THEN]
44:
45: 20 Constant bl ( -- c-char ) \ core b-l
46: \G @i{c-char} is the character value for a space.
47: \ used by docon:, must be constant
48:
49: FF Constant /line
50:
51: has? file [IF]
52: 40 Constant c/l
53: 10 Constant l/s
54: 400 Constant chars/block
55: [THEN]
56:
57: 20 8 2* cells + 2 + cell+ constant word-pno-size ( -- u )
58:
59: has? EC 0= [IF]
60: create holdbuf word-pno-size chars allot
61: holdbuf word-pno-size chars + aconstant holdbuf-end
62: avariable holdptr holdbuf-end holdptr a!
63: avariable holdend holdbuf-end holdend a!
64: [THEN]
65:
66: 84 constant pad-minsize ( -- u )
67:
68: $400 Value def#tib
69: \G default size of terminal input buffer. Default size is 1K
70:
71: \ that's enough so long
72:
73: \ User variables 13feb93py
74:
75: \ initialized by COLD
76:
77: has? no-userspace 0= [IF]
78: Create main-task has? OS [IF] 100 [ELSE] 40 [THEN] cells dup allot
79:
80: \ set user-pointer from cross-compiler right
81: main-task
82: UNLOCK swap region user-region user-region setup-region LOCK
83:
84: Variable udp ( -- a-addr ) \ gforth
85: \G user area size
86:
87: AUser next-task main-task next-task !
88: AUser prev-task main-task prev-task !
89: AUser save-task 0 save-task !
90: [THEN]
91: AUser sp0 ( -- a-addr ) \ gforth
92: \G @code{User} variable -- initial value of the data stack pointer.
93: \ sp0 is used by douser:, must be user
94: \ ' sp0 Alias s0 ( -- a-addr ) \ gforth
95: \G OBSOLETE alias of @code{sp0}
96:
97: AUser rp0 ( -- a-addr ) \ gforth
98: \G @code{User} variable -- initial value of the return stack pointer.
99: \ ' rp0 Alias r0 ( -- a-addr ) \ gforth
100: \G OBSOLETE alias of @code{rp0}
101:
102: has? floating [IF]
103: AUser fp0 ( -- a-addr ) \ gforth
104: \G @code{User} variable -- initial value of the floating-point stack pointer.
105: \ no f0, because this leads to unexpected results when using hex
106: [THEN]
107:
108: has? glocals [IF]
109: AUser lp0 ( -- a-addr ) \ gforth
110: \G @code{User} variable -- initial value of the locals stack pointer.
111: \ ' lp0 Alias l0 ( -- a-addr ) \ gforth
112: \G OBSOLETE alias of @code{lp0}
113: [THEN]
114:
115: AUser handler \ pointer to last throw frame
116: has? backtrace [IF]
117: User backtrace-empty \ true if the next THROW should store a backtrace
118: AUser backtrace-rp0 \ rp at last call of interpret
119: [THEN]
120: \ AUser output
121: \ AUser input
122:
123: AUser errorhandler
124:
125: AUser "error 0 "error !
126:
127: has? new-input [IF]
128: User current-input
129: [ELSE]
130: [IFUNDEF] #tib \ in ec-Version we may define this ourself
131: User tibstack \ saves >tib in execute
132: User >tib \ pointer to terminal input buffer
133: User #tib ( -- a-addr ) \ core-ext number-t-i-b
134: \G @code{User} variable -- @i{a-addr} is the address of a cell containing
135: \G the number of characters in the terminal input buffer.
136: \G OBSOLESCENT: @code{source} superceeds the function of this word.
137:
138: User >in ( -- a-addr ) \ core to-in
139: \G @code{User} variable -- @i{a-addr} is the address of a cell containing the
140: \G char offset from the start of the input buffer to the start of the
141: \G parse area.
142: 0 >in ! \ char number currently processed in tib
143: [THEN]
144:
145: has? file [IF]
146: User blk ( -- a-addr ) \ block b-l-k
147: \G @code{User} variable -- @i{a-addr} is the address of a cell containing zero
148: \G (in which case the input source is not a block and can be identified
149: \G by @code{source-id}) or the number of the block currently being
150: \G interpreted. A Standard program should not alter @code{blk} directly.
151: 0 blk !
152:
153: User loadfile 0 loadfile !
154:
155: 2user loadfilename 0 0 loadfilename 2! \ addr u for sourcefilename
156:
157: User loadline \ number of the currently interpreted
158: \ (in TIB) line if the interpretation
159: \ is in a textfile
160: \ the first line is 1
161:
162: 2User linestart \ starting file postition of
163: \ the current interpreted line (in TIB)
164: [THEN]
165: [THEN]
166:
167: 2user includefilename 0 0 includefilename 2! \ innermost included file
168:
169:
170: User base ( -- a-addr ) \ core
171: \G @code{User} variable -- @i{a-addr} is the address of a cell that stores the
172: \G number base used by default for number conversion during input and output.
173: A base !
174: User dpl ( -- a-addr ) \ gforth
175: \G @code{User} variable -- @i{a-addr} is the address of a cell that stores the
176: \G position of the decimal point in the most recent numeric conversion.
177: \G Initialised to -1. After the conversion of a number containing no
178: \G decimal point, @code{dpl} is -1. After the conversion of @code{2.} it holds
179: \G 0. After the conversion of 234123.9 it contains 1, and so forth.
180: -1 dpl !
181:
182: User state ( -- a-addr ) \ core,tools-ext
183: \G @code{User} variable -- @i{a-addr} is the address of a cell
184: \G containing the compilation state flag. 0 => interpreting, -1 =>
185: \G compiling. A program shall not directly alter the value of
186: \G @code{state}. The following Standard words alter the value in
187: \G @code{state}: @code{:} (colon) @code{;} (semicolon) @code{abort}
188: \G @code{quit} @code{:noname} @code{[} (left-bracket) @code{]}
189: \G (right-bracket) @code{;code}. Don't use @code{state}! For an
190: \G alternative see @ref{Interpretation and Compilation Semantics}.
191: \ Recommended reading: @cite{@code{State}-smartness--Why it is evil
192: \ and how to exorcise it},
193: \ @url{http://www.complang.tuwien.ac.at/papers/ertl98.ps.gz}; short
194: \ version: Don't use @code{state}!
195: 0 state !
196:
197: AUser normal-dp \ the usual dictionary pointer
198: AUser dpp normal-dp dpp !
199: \ the pointer to the current dictionary pointer
200: \ ist reset to normal-dp on (doerror)
201: \ (i.e. any throw caught by quit)
202: AUser LastCFA
203: AUser Last
204:
205: has? flash [IF]
206: AUser flash-dp
207: : rom flash-dp dpp ! ;
208: : ram normal-dp dpp ! ;
209: [THEN]
210:
211: User max-name-length \ maximum length of all names defined yet
212: 32 max-name-length !
213:
214: \ has? peephole [IF]
215: \ 0 value peeptable \ initialized in boot
216: \ [THEN]
217:
218: has? glocals [IF]
219: User locals-size \ this is the current size of the locals stack
220: \ frame of the current word
221: [THEN]
222:
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