--- gforth/kernel/vars.fs 1997/05/21 20:40:18 1.1 +++ gforth/kernel/vars.fs 1999/05/06 21:33:37 1.17 @@ -1,6 +1,6 @@ \ VARS.FS Kernal variables -\ Copyright (C) 1995 Free Software Foundation, Inc. +\ Copyright (C) 1995,1996,1997,1998 Free Software Foundation, Inc. \ This file is part of Gforth. @@ -25,14 +25,24 @@ 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 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 CONSTANT: @i{f} is a cell with all bits clear. + +[IFUNDEF] cell 1 cells Constant cell ( -- u ) \ gforth +\G CONSTANT: the number of address units corresponding to 1 cell. +[THEN] + 1 floats Constant float ( -- u ) \ gforth +\G CONSTANT: the number of address units corresponding to a floating-point number. -20 Constant bl \ used by docon:, must be constant +20 Constant bl ( -- c-char ) \ core +\G @i{c-char} is the character value for a space. +\ used by docon:, must be constant FF Constant /line @@ -40,25 +50,55 @@ FF Constant /line 10 Constant l/s 400 Constant chars/block +$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 ) + + \ that's enough so long \ User variables 13feb93py \ initialized by COLD -Create main-task 100 cells allot -main-task tup H ! minimal +Create main-task has? OS [IF] 100 [ELSE] 40 [THEN] cells allot + +\ set user-pointer from cross-compiler right +main-task +UNLOCK tup ! LOCK -Variable udp \ used by dovar:, must be variable +Variable udp \ user area size? -anton AUser next-task main-task next-task ! AUser prev-task main-task prev-task ! AUser save-task 0 save-task ! -AUser s0 \ used by douser:, must be user -AUser r0 -AUser f0 -AUser l0 -AUser handler +AUser sp0 ( -- a-addr ) \ gforth +\G 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 USER VARIABLE: Initial value of the return stack pointer. + ' rp0 Alias r0 ( -- a-addr ) \ gforth +\G OBSOLETE alias of @code{rp0} + +AUser fp0 ( -- a-addr ) \ gforth +\G USER VARIABLE: Initial value of the floating-point stack pointer. +\ no f0, because this leads to unexpected results when using hex + +AUser lp0 ( -- a-addr ) \ gforth +\G USER VARIABLE: Initial value of the locals stack pointer. + ' lp0 Alias l0 ( -- a-addr ) \ gforth +\G OBSOLETE alias of @code{lp0} + +AUser handler \ pointer to last throw frame +User backtrace-empty \ true if the next THROW should store a backtrace +AUser backtrace-rp0 \ rp at last call of interpret \ AUser output \ AUser input @@ -66,11 +106,28 @@ AUser errorhandler AUser "error 0 "error ! - User tibstack - User >tib - User #tib - User >in 0 >in ! - User blk 0 blk ! +[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 + \G 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 + \G 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 ( -- a-addr ) \ block + \G 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# ! @@ -82,11 +139,35 @@ AUser "error 0 "error ! 2User linestart \ starting file postition of \ the current interpreted line (in TIB) +[THEN] - User base A base ! - User dpl -1 dpl ! + User base ( -- a-addr ) \ core + \G 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 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 USER VARIABLE: @i{a-addr} is the address of a cell containing the + \G compilation state flag. 0 => interpreting, -1 => compiling. A + \G program shall not directly alter the value of @code{state}. The + \G following Standard words alter the value in @code{state}: @code{:} + \G (colon) @code{;} (semicolon) @code{abort} @code{quit} + \G @code{:noname} @code{[} (left-bracket) @code{]} (right-bracket) + \G @code{;code}. Don't use @code{state}! @xref{Interpretation and + \G Compilation Semantics} for an alternative. + \ 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 @@ -95,7 +176,8 @@ AUser dpp normal-dp dpp ! AUser LastCFA AUser Last +has? glocals [IF] User locals-size \ this is the current size of the locals stack \ frame of the current word - +[THEN]