--- gforth/kernel/vars.fs 1997/07/06 13:40:50 1.3 +++ gforth/kernel/vars.fs 1999/03/08 21:36:08 1.13 @@ -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 +25,19 @@ 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: f is a cell with all bits set. +\ see starts looking for primitives after this word! + + 0 Constant false ( -- f ) \ core-ext +\G CONSTANT: f is a cell with all bits clear. 1 cells Constant cell ( -- u ) \ gforth 1 floats Constant float ( -- u ) \ gforth -20 Constant bl \ used by docon:, must be constant +20 Constant bl ( -- c-char ) \ core +\G c-char is the character value for a space. +\ used by docon:, must be constant FF Constant /line @@ -41,31 +46,54 @@ FF Constant /line 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 +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 sp0 \ used by douser:, must be user - ' sp0 Alias s0 -AUser rp0 ' rp0 Alias r0 -AUser fp0 ' fp0 Alias f0 -AUser lp0 ' lp0 Alias l0 +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 @@ -76,10 +104,25 @@ 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 + User #tib ( -- a-addr ) \ core-ext + \G USER VARIABLE: 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: a-addr is the address of a cell containing the + \G char offset from the start of the terminal input buffer to the + \G start of the parse area + 0 >in ! \ char number currently processed in tib [THEN] - User blk 0 blk ! +has? file [IF] + User blk ( -- a-addr ) \ block + \G USER VARIABLE: 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# ! @@ -91,11 +134,28 @@ AUser "error 0 "error ! 2User linestart \ starting file postition of \ the current interpreted line (in TIB) +[THEN] - User base A base ! + User base ( -- a-addr ) \ core + \G USER VARIABLE: 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 -1 dpl ! - User state 0 state ! + User state ( -- a-addr ) \ core,tools-ext + \G Recommended reading: @cite{@code{State}-smartness--Why it is evil + \G and how to exorcise it}, + \G @url{http://www.complang.tuwien.ac.at/papers/ertl98.ps.gz}; short + \G version: Don't use @code{state}! @xref{Interpretation and + \G Compilation Semantics} for an alternative. USER VARIABLE: a-addr + \G is the address of a cell containing the compilation state flag. 0 + \G => interpreting, -1 => compiling. A program shall not directly + \G alter the value of @code{state}. The following Standard words + \G alter the value in @code{state}: @code{:} (colon) @code{;} + \G (semicolon) @code{abort} @code{quit} @code{:noname} @code{[} + \G (left-bracket) @code{]} (right-bracket) @code{;code} + 0 state ! + AUser normal-dp \ the usual dictionary pointer AUser dpp normal-dp dpp ! \ the pointer to the current dictionary pointer @@ -104,7 +164,8 @@ 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]