Annotation of gforth/kernel/vars.fs, revision 1.37
1.1 anton 1: \ VARS.FS Kernal variables
2:
1.34 anton 3: \ Copyright (C) 1995,1996,1997,1998,2000,2003 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
1.24 anton 19: \ Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111, USA.
1.1 anton 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
1.19 crook 29: \G @code{Constant} -- @i{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
1.19 crook 33: \G @code{Constant} -- @i{f} is a cell with all bits clear.
1.1 anton 34:
1.16 jwilke 35: [IFUNDEF] cell
1.1 anton 36: 1 cells Constant cell ( -- u ) \ gforth
1.22 anton 37: \G @code{Constant} -- @code{1 cells}
1.16 jwilke 38: [THEN]
1.17 crook 39:
1.25 pazsan 40: has? floating [IF]
1.1 anton 41: 1 floats Constant float ( -- u ) \ gforth
1.19 crook 42: \G @code{Constant} -- the number of address units corresponding to a floating-point number.
1.25 pazsan 43: [THEN]
1.1 anton 44:
1.20 crook 45: 20 Constant bl ( -- c-char ) \ core b-l
1.17 crook 46: \G @i{c-char} is the character value for a space.
1.10 crook 47: \ used by docon:, must be constant
1.1 anton 48:
49: FF Constant /line
50:
51: 40 Constant c/l
52: 10 Constant l/s
53: 400 Constant chars/block
54:
1.18 jwilke 55: 20 8 2* cells + 2 + cell+ constant word-pno-size ( -- u )
1.11 anton 56: create holdbuf word-pno-size chars allot
57: holdbuf word-pno-size chars + aconstant holdbuf-end
58: avariable holdptr holdbuf-end holdptr a!
1.12 anton 59: avariable holdend holdbuf-end holdend a!
1.11 anton 60:
1.2 anton 61: 84 constant pad-minsize ( -- u )
1.11 anton 62:
1.25 pazsan 63: $400 Value def#tib
64: \G default size of terminal input buffer. Default size is 1K
1.2 anton 65:
1.1 anton 66: \ that's enough so long
67:
68: \ User variables 13feb93py
69:
70: \ initialized by COLD
71:
1.35 jwilke 72: Create main-task has? OS [IF] 100 [ELSE] 40 [THEN] cells dup allot
1.3 jwilke 73:
74: \ set user-pointer from cross-compiler right
75: main-task
1.35 jwilke 76: UNLOCK swap region user-region user-region setup-region LOCK
1.1 anton 77:
1.19 crook 78: Variable udp ( -- a-addr ) \ gforth
1.28 pazsan 79: \G user area size
1.1 anton 80:
81: AUser next-task main-task next-task !
82: AUser prev-task main-task prev-task !
83: AUser save-task 0 save-task !
1.10 crook 84: AUser sp0 ( -- a-addr ) \ gforth
1.19 crook 85: \G @code{User} variable -- initial value of the data stack pointer.
1.10 crook 86: \ sp0 is used by douser:, must be user
87: ' sp0 Alias s0 ( -- a-addr ) \ gforth
88: \G OBSOLETE alias of @code{sp0}
89:
90: AUser rp0 ( -- a-addr ) \ gforth
1.19 crook 91: \G @code{User} variable -- initial value of the return stack pointer.
1.10 crook 92: ' rp0 Alias r0 ( -- a-addr ) \ gforth
93: \G OBSOLETE alias of @code{rp0}
94:
1.25 pazsan 95: has? floating [IF]
1.10 crook 96: AUser fp0 ( -- a-addr ) \ gforth
1.19 crook 97: \G @code{User} variable -- initial value of the floating-point stack pointer.
1.10 crook 98: \ no f0, because this leads to unexpected results when using hex
1.25 pazsan 99: [THEN]
1.10 crook 100:
1.25 pazsan 101: has? glocals [IF]
1.10 crook 102: AUser lp0 ( -- a-addr ) \ gforth
1.19 crook 103: \G @code{User} variable -- initial value of the locals stack pointer.
1.10 crook 104: ' lp0 Alias l0 ( -- a-addr ) \ gforth
105: \G OBSOLETE alias of @code{lp0}
1.25 pazsan 106: [THEN]
1.10 crook 107:
1.3 jwilke 108: AUser handler \ pointer to last throw frame
1.18 jwilke 109: has? backtrace [IF]
1.13 anton 110: User backtrace-empty \ true if the next THROW should store a backtrace
111: AUser backtrace-rp0 \ rp at last call of interpret
1.18 jwilke 112: [THEN]
1.1 anton 113: \ AUser output
114: \ AUser input
115:
116: AUser errorhandler
117:
118: AUser "error 0 "error !
119:
1.25 pazsan 120: has? new-input [IF]
121: User current-input
122: [ELSE]
123: [IFUNDEF] #tib \ in ec-Version we may define this ourself
124: User tibstack \ saves >tib in execute
125: User >tib \ pointer to terminal input buffer
126: User #tib ( -- a-addr ) \ core-ext number-t-i-b
127: \G @code{User} variable -- @i{a-addr} is the address of a cell containing
128: \G the number of characters in the terminal input buffer.
129: \G OBSOLESCENT: @code{source} superceeds the function of this word.
130:
131: User >in ( -- a-addr ) \ core to-in
132: \G @code{User} variable -- @i{a-addr} is the address of a cell containing the
133: \G char offset from the start of the input buffer to the start of the
134: \G parse area.
135: 0 >in ! \ char number currently processed in tib
136: [THEN]
137:
1.7 pazsan 138: has? file [IF]
1.20 crook 139: User blk ( -- a-addr ) \ block b-l-k
1.19 crook 140: \G @code{User} variable -- @i{a-addr} is the address of a cell containing zero
1.10 crook 141: \G (in which case the input source is not a block and can be identified
142: \G by @code{source-id}) or the number of the block currently being
143: \G interpreted. A Standard program should not alter @code{blk} directly.
144: 0 blk !
145:
1.1 anton 146: User loadfile 0 loadfile !
147:
1.32 anton 148: 2user loadfilename 0 0 loadfilename 2! \ addr u for sourcefilename
1.37 ! anton 149:
1.1 anton 150: User loadline \ number of the currently interpreted
151: \ (in TIB) line if the interpretation
152: \ is in a textfile
153: \ the first line is 1
154:
155: 2User linestart \ starting file postition of
156: \ the current interpreted line (in TIB)
1.25 pazsan 157: [THEN]
1.7 pazsan 158: [THEN]
1.37 ! anton 159:
! 160: 2user includefilename 0 0 includefilename 2! \ innermost included file
! 161:
1.1 anton 162:
1.26 anton 163: User base ( -- a-addr ) \ core
164: \G @code{User} variable -- @i{a-addr} is the address of a cell that stores the
165: \G number base used by default for number conversion during input and output.
166: A base !
167: User dpl ( -- a-addr ) \ gforth
168: \G @code{User} variable -- @i{a-addr} is the address of a cell that stores the
169: \G position of the decimal point in the most recent numeric conversion.
170: \G Initialised to -1. After the conversion of a number containing no
1.36 anton 171: \G decimal point, @code{dpl} is -1. After the conversion of @code{2.} it holds
1.26 anton 172: \G 0. After the conversion of 234123.9 it contains 1, and so forth.
173: -1 dpl !
1.1 anton 174:
1.26 anton 175: User state ( -- a-addr ) \ core,tools-ext
176: \G @code{User} variable -- @i{a-addr} is the address of a cell
177: \G containing the compilation state flag. 0 => interpreting, -1 =>
178: \G compiling. A program shall not directly alter the value of
179: \G @code{state}. The following Standard words alter the value in
180: \G @code{state}: @code{:} (colon) @code{;} (semicolon) @code{abort}
181: \G @code{quit} @code{:noname} @code{[} (left-bracket) @code{]}
182: \G (right-bracket) @code{;code}. Don't use @code{state}! For an
183: \G alternative see @ref{Interpretation and Compilation Semantics}.
184: \ Recommended reading: @cite{@code{State}-smartness--Why it is evil
185: \ and how to exorcise it},
186: \ @url{http://www.complang.tuwien.ac.at/papers/ertl98.ps.gz}; short
187: \ version: Don't use @code{state}!
188: 0 state !
1.10 crook 189:
1.1 anton 190: AUser normal-dp \ the usual dictionary pointer
191: AUser dpp normal-dp dpp !
192: \ the pointer to the current dictionary pointer
193: \ ist reset to normal-dp on (doerror)
194: \ (i.e. any throw caught by quit)
195: AUser LastCFA
196: AUser Last
1.26 anton 197:
1.33 anton 198: User max-name-length \ maximum length of all names defined yet
199: 32 max-name-length !
200:
201: \ has? peephole [IF]
202: \ 0 value peeptable \ initialized in boot
203: \ [THEN]
1.1 anton 204:
1.7 pazsan 205: has? glocals [IF]
1.1 anton 206: User locals-size \ this is the current size of the locals stack
207: \ frame of the current word
1.7 pazsan 208: [THEN]
1.1 anton 209:
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