--- gforth/kernel/vars.fs 1999/02/21 14:55:45 1.11 +++ gforth/kernel/vars.fs 1999/05/05 12:04:41 1.16 @@ -26,17 +26,19 @@ hex \ everything now hex! \ "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 ( -- f ) \ core-ext -\G CONSTANT: f is a cell with all bits set. +\G CONSTANT: @var{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. +\G CONSTANT: @var{f} is a cell with all bits clear. +[IFUNDEF] cell 1 cells Constant cell ( -- u ) \ gforth +[THEN] 1 floats Constant float ( -- u ) \ gforth 20 Constant bl ( -- c-char ) \ core -\G c-char is the character value for a space. +\G @var{c-char} is the character value for a space. \ used by docon:, must be constant FF Constant /line @@ -49,6 +51,7 @@ $20 8 2* cells + 2 + cell+ constant word 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 ) @@ -91,7 +94,8 @@ AUser lp0 ( -- a-addr ) \ gforth \G OBSOLETE alias of @code{lp0} AUser handler \ pointer to last throw frame -AUser backtrace-empty \ true if the next THROW should store a backtrace +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 @@ -103,19 +107,19 @@ AUser "error 0 "error ! User tibstack \ saves >tib in execute User >tib \ pointer to terminal input buffer User #tib ( -- a-addr ) \ core-ext - \G USER VARIABLE: a-addr is the address of a cell containing + \G USER VARIABLE: @var{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 USER VARIABLE: @var{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 + \G start of the parse area. 0 >in ! \ char number currently processed in tib [THEN] has? file [IF] User blk ( -- a-addr ) \ block - \G USER VARIABLE: a-addr is the address of a cell containing zero + \G USER VARIABLE: @var{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. @@ -135,19 +139,23 @@ has? file [IF] [THEN] User base ( -- a-addr ) \ core - \G USER VARIABLE: a-addr is the address of a cell that stores the + \G USER VARIABLE: @var{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 ( -- a-addr ) \ core,tools-ext - \G USER VARIABLE: a-addr is the address of a cell containing - \G the compilation state flag. 0 => interpreting, -1 => compiling. - \G A program shall not directly alter the value of @code{state}. The - \G following Standard words alter the value in @code{state}: - \G @code{:} (colon) @code{;} (semicolon) @code{abort} @code{quit} - \G @code{:noname} @code{[} (left-bracket) @code{]} (right-bracket) - \G @code{;code} + \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: @var{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