Annotation of gforth/kernel/vars.fs, revision 1.15
1.1 anton 1: \ VARS.FS Kernal variables
2:
1.6 anton 3: \ Copyright (C) 1995,1996,1997,1998 Free Software Foundation, Inc.
1.1 anton 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)
1.10 crook 28: -1 Constant true ( -- f ) \ core-ext
1.14 crook 29: \G CONSTANT: @var{f} is a cell with all bits set.
1.10 crook 30: \ see starts looking for primitives after this word!
31:
32: 0 Constant false ( -- f ) \ core-ext
1.14 crook 33: \G CONSTANT: @var{f} is a cell with all bits clear.
1.1 anton 34:
35: 1 cells Constant cell ( -- u ) \ gforth
36: 1 floats Constant float ( -- u ) \ gforth
37:
1.10 crook 38: 20 Constant bl ( -- c-char ) \ core
1.14 crook 39: \G @var{c-char} is the character value for a space.
1.10 crook 40: \ used by docon:, must be constant
1.1 anton 41:
42: FF Constant /line
43:
44: 40 Constant c/l
45: 10 Constant l/s
46: 400 Constant chars/block
47:
1.2 anton 48: $20 8 2* cells + 2 + cell+ constant word-pno-size ( -- u )
1.11 anton 49: create holdbuf word-pno-size chars allot
50: holdbuf word-pno-size chars + aconstant holdbuf-end
51: avariable holdptr holdbuf-end holdptr a!
1.12 anton 52: avariable holdend holdbuf-end holdend a!
1.11 anton 53:
1.2 anton 54: 84 constant pad-minsize ( -- u )
1.11 anton 55:
1.2 anton 56:
1.1 anton 57: \ that's enough so long
58:
59: \ User variables 13feb93py
60:
61: \ initialized by COLD
62:
1.7 pazsan 63: Create main-task has? OS [IF] 100 [ELSE] 40 [THEN] cells allot
1.3 jwilke 64:
65: \ set user-pointer from cross-compiler right
66: main-task
67: UNLOCK tup ! LOCK
1.1 anton 68:
1.8 anton 69: Variable udp \ user area size? -anton
1.1 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 !
1.10 crook 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:
1.3 jwilke 94: AUser handler \ pointer to last throw frame
1.13 anton 95: User backtrace-empty \ true if the next THROW should store a backtrace
96: AUser backtrace-rp0 \ rp at last call of interpret
1.1 anton 97: \ AUser output
98: \ AUser input
99:
100: AUser errorhandler
101:
102: AUser "error 0 "error !
103:
1.3 jwilke 104: [IFUNDEF] #tib \ in ec-Version we may define this ourself
105: User tibstack \ saves >tib in execute
106: User >tib \ pointer to terminal input buffer
1.10 crook 107: User #tib ( -- a-addr ) \ core-ext
1.14 crook 108: \G USER VARIABLE: @var{a-addr} is the address of a cell containing
1.10 crook 109: \G the number of characters in the terminal input buffer.
110: \G OBSOLESCENT: @code{source} superceeds the function of this word.
111:
112: User >in ( -- a-addr ) \ core
1.14 crook 113: \G USER VARIABLE: @var{a-addr} is the address of a cell containing the
1.10 crook 114: \G char offset from the start of the terminal input buffer to the
1.15 ! crook 115: \G start of the parse area.
1.10 crook 116: 0 >in ! \ char number currently processed in tib
1.3 jwilke 117: [THEN]
1.7 pazsan 118: has? file [IF]
1.10 crook 119: User blk ( -- a-addr ) \ block
1.14 crook 120: \G USER VARIABLE: @var{a-addr} is the address of a cell containing zero
1.10 crook 121: \G (in which case the input source is not a block and can be identified
122: \G by @code{source-id}) or the number of the block currently being
123: \G interpreted. A Standard program should not alter @code{blk} directly.
124: 0 blk !
125:
1.1 anton 126: User loadfile 0 loadfile !
127:
128: User loadfilename# 0 loadfilename# !
129:
130: User loadline \ number of the currently interpreted
131: \ (in TIB) line if the interpretation
132: \ is in a textfile
133: \ the first line is 1
134:
135: 2User linestart \ starting file postition of
136: \ the current interpreted line (in TIB)
1.7 pazsan 137: [THEN]
1.1 anton 138:
1.10 crook 139: User base ( -- a-addr ) \ core
1.14 crook 140: \G USER VARIABLE: @var{a-addr} is the address of a cell that stores the
1.10 crook 141: \G number base used by default for number conversion during input and output.
142: A base !
1.1 anton 143: User dpl -1 dpl !
144:
1.10 crook 145: User state ( -- a-addr ) \ core,tools-ext
1.12 anton 146: \G Recommended reading: @cite{@code{State}-smartness--Why it is evil
147: \G and how to exorcise it},
148: \G @url{http://www.complang.tuwien.ac.at/papers/ertl98.ps.gz}; short
149: \G version: Don't use @code{state}! @xref{Interpretation and
1.14 crook 150: \G Compilation Semantics} for an alternative. USER VARIABLE: @var{a-addr}
1.12 anton 151: \G is the address of a cell containing the compilation state flag. 0
152: \G => interpreting, -1 => compiling. A program shall not directly
153: \G alter the value of @code{state}. The following Standard words
154: \G alter the value in @code{state}: @code{:} (colon) @code{;}
155: \G (semicolon) @code{abort} @code{quit} @code{:noname} @code{[}
156: \G (left-bracket) @code{]} (right-bracket) @code{;code}
1.10 crook 157: 0 state !
158:
1.1 anton 159: AUser normal-dp \ the usual dictionary pointer
160: AUser dpp normal-dp dpp !
161: \ the pointer to the current dictionary pointer
162: \ ist reset to normal-dp on (doerror)
163: \ (i.e. any throw caught by quit)
164: AUser LastCFA
165: AUser Last
166:
1.7 pazsan 167: has? glocals [IF]
1.1 anton 168: User locals-size \ this is the current size of the locals stack
169: \ frame of the current word
1.7 pazsan 170: [THEN]
1.1 anton 171:
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