--- gforth/kernel/vars.fs 1998/12/19 13:43:18 1.8 +++ gforth/kernel/vars.fs 2003/01/20 19:17:59 1.32 @@ -1,6 +1,6 @@ \ VARS.FS Kernal variables -\ Copyright (C) 1995,1996,1997,1998 Free Software Foundation, Inc. +\ Copyright (C) 1995,1996,1997,1998,2000 Free Software Foundation, Inc. \ This file is part of Gforth. @@ -16,7 +16,7 @@ \ You should have received a copy of the GNU General Public License \ along with this program; if not, write to the Free Software -\ Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. +\ Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111, USA. hex \ everything now hex! 11may93jaw @@ -25,14 +25,26 @@ hex \ everything now hex! \ dpANS6 (sect 3.1.3.1) says \ "a true flag ... [is] a single-cell value with all bits set" \ better definition: 0 0= constant true ( no dependence on 2's compl) - -1 Constant true \ see starts looking for - \ primitives after this word! - 0 Constant false + -1 Constant true ( -- f ) \ core-ext +\G @code{Constant} -- @i{f} is a cell with all bits set. +\ see starts looking for primitives after this word! + 0 Constant false ( -- f ) \ core-ext +\G @code{Constant} -- @i{f} is a cell with all bits clear. + +[IFUNDEF] cell 1 cells Constant cell ( -- u ) \ gforth +\G @code{Constant} -- @code{1 cells} +[THEN] + +has? floating [IF] 1 floats Constant float ( -- u ) \ gforth +\G @code{Constant} -- the number of address units corresponding to a floating-point number. +[THEN] -20 Constant bl \ used by docon:, must be constant +20 Constant bl ( -- c-char ) \ core b-l +\G @i{c-char} is the character value for a space. +\ used by docon:, must be constant FF Constant /line @@ -40,9 +52,17 @@ FF Constant /line 10 Constant l/s 400 Constant chars/block -$20 8 2* cells + 2 + cell+ constant word-pno-size ( -- u ) +20 8 2* cells + 2 + cell+ constant word-pno-size ( -- u ) +create holdbuf word-pno-size chars allot +holdbuf word-pno-size chars + aconstant holdbuf-end +avariable holdptr holdbuf-end holdptr a! +avariable holdend holdbuf-end holdend a! + 84 constant pad-minsize ( -- u ) +$400 Value def#tib +\G default size of terminal input buffer. Default size is 1K + \ that's enough so long \ User variables 13feb93py @@ -55,17 +75,41 @@ Create main-task has? OS [IF] 100 [ELSE main-task UNLOCK tup ! LOCK -Variable udp \ user area size? -anton +Variable udp ( -- a-addr ) \ gforth +\G user area size AUser next-task main-task next-task ! AUser prev-task main-task prev-task ! AUser save-task 0 save-task ! -AUser sp0 \ used by douser:, must be user - ' sp0 Alias s0 -AUser rp0 ' rp0 Alias r0 -AUser fp0 \ no f0, because this leads to unexpected results -AUser lp0 ' lp0 Alias l0 +AUser sp0 ( -- a-addr ) \ gforth +\G @code{User} variable -- initial value of the data stack pointer. +\ sp0 is used by douser:, must be user + ' sp0 Alias s0 ( -- a-addr ) \ gforth +\G OBSOLETE alias of @code{sp0} + +AUser rp0 ( -- a-addr ) \ gforth +\G @code{User} variable -- initial value of the return stack pointer. + ' rp0 Alias r0 ( -- a-addr ) \ gforth +\G OBSOLETE alias of @code{rp0} + +has? floating [IF] +AUser fp0 ( -- a-addr ) \ gforth +\G @code{User} variable -- initial value of the floating-point stack pointer. +\ no f0, because this leads to unexpected results when using hex +[THEN] + +has? glocals [IF] +AUser lp0 ( -- a-addr ) \ gforth +\G @code{User} variable -- initial value of the locals stack pointer. + ' lp0 Alias l0 ( -- a-addr ) \ gforth +\G OBSOLETE alias of @code{lp0} +[THEN] + AUser handler \ pointer to last throw frame +has? backtrace [IF] +User backtrace-empty \ true if the next THROW should store a backtrace +AUser backtrace-rp0 \ rp at last call of interpret +[THEN] \ AUser output \ AUser input @@ -73,17 +117,35 @@ AUser errorhandler AUser "error 0 "error ! -[IFUNDEF] #tib \ in ec-Version we may define this ourself - User tibstack \ saves >tib in execute - User >tib \ pointer to terminal input buffer - User #tib \ chars in terminal input buffer - User >in 0 >in ! \ char number currently processed in tib -[THEN] +has? new-input [IF] + User current-input +[ELSE] + [IFUNDEF] #tib \ in ec-Version we may define this ourself + User tibstack \ saves >tib in execute + User >tib \ pointer to terminal input buffer + User #tib ( -- a-addr ) \ core-ext number-t-i-b + \G @code{User} variable -- @i{a-addr} is the address of a cell containing + \G the number of characters in the terminal input buffer. + \G OBSOLESCENT: @code{source} superceeds the function of this word. + + User >in ( -- a-addr ) \ core to-in + \G @code{User} variable -- @i{a-addr} is the address of a cell containing the + \G char offset from the start of the input buffer to the start of the + \G parse area. + 0 >in ! \ char number currently processed in tib + [THEN] + has? file [IF] - User blk 0 blk ! + User blk ( -- a-addr ) \ block b-l-k + \G @code{User} variable -- @i{a-addr} is the address of a cell containing zero + \G (in which case the input source is not a block and can be identified + \G by @code{source-id}) or the number of the block currently being + \G interpreted. A Standard program should not alter @code{blk} directly. + 0 blk ! + User loadfile 0 loadfile ! - User loadfilename# 0 loadfilename# ! + 2user loadfilename 0 0 loadfilename 2! \ addr u for sourcefilename User loadline \ number of the currently interpreted \ (in TIB) line if the interpretation @@ -93,11 +155,35 @@ has? file [IF] 2User linestart \ starting file postition of \ the current interpreted line (in TIB) [THEN] +[THEN] - User base A base ! - User dpl -1 dpl ! +User base ( -- a-addr ) \ core +\G @code{User} variable -- @i{a-addr} is the address of a cell that stores the +\G number base used by default for number conversion during input and output. + A base ! +User dpl ( -- a-addr ) \ gforth +\G @code{User} variable -- @i{a-addr} is the address of a cell that stores the +\G position of the decimal point in the most recent numeric conversion. +\G Initialised to -1. After the conversion of a number containing no +\G decimal point, @code{@ dpl} is -1. After the conversion of @code{2.} it holds +\G 0. After the conversion of 234123.9 it contains 1, and so forth. +-1 dpl ! + +User state ( -- a-addr ) \ core,tools-ext +\G @code{User} variable -- @i{a-addr} is the address of a cell +\G containing the compilation state flag. 0 => interpreting, -1 => +\G compiling. A program shall not directly alter the value of +\G @code{state}. The following Standard words alter the value in +\G @code{state}: @code{:} (colon) @code{;} (semicolon) @code{abort} +\G @code{quit} @code{:noname} @code{[} (left-bracket) @code{]} +\G (right-bracket) @code{;code}. Don't use @code{state}! For an +\G alternative see @ref{Interpretation and Compilation Semantics}. +\ Recommended reading: @cite{@code{State}-smartness--Why it is evil +\ and how to exorcise it}, +\ @url{http://www.complang.tuwien.ac.at/papers/ertl98.ps.gz}; short +\ version: Don't use @code{state}! +0 state ! - User state 0 state ! AUser normal-dp \ the usual dictionary pointer AUser dpp normal-dp dpp ! \ the pointer to the current dictionary pointer @@ -106,6 +192,15 @@ AUser dpp normal-dp dpp ! AUser LastCFA AUser Last +AUser last-compiled \ last compile,d xt + \ 0 if last xt was dyn-compiled already (basic-block-end) +0 last-compiled ! +AUser last-compiled-here \ where LAST-COMPILED should be stored + +has? peephole [IF] +0 value peeptable \ initialized in boot +[THEN] + has? glocals [IF] User locals-size \ this is the current size of the locals stack \ frame of the current word