\ search order wordset 14may93py \ Copyright (C) 1995,1996,1997,1998 Free Software Foundation, Inc. \ This file is part of Gforth. \ Gforth is free software; you can redistribute it and/or \ modify it under the terms of the GNU General Public License \ as published by the Free Software Foundation; either version 2 \ of the License, or (at your option) any later version. \ This program is distributed in the hope that it will be useful, \ but WITHOUT ANY WARRANTY; without even the implied warranty of \ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the \ GNU General Public License for more details. \ 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. $10 constant maxvp Variable vp 0 A, 0 A, 0 A, 0 A, 0 A, 0 A, 0 A, 0 A, 0 A, 0 A, 0 A, 0 A, 0 A, 0 A, 0 A, 0 A, : get-current ( -- wid ) \ search \G wid is the identifier of the current compilation word list. current @ ; : set-current ( wid -- ) \ search \G Set the compilation word list to the word list identified by wid. current ! ; \ : context ( -- addr ) vp dup @ cells + ; : vp! dup vp ! cells vp + to context ; : definitions ( -- ) \ search \G Make the compilation word list the same as the word list \G that is currently at the top of the search order stack. context @ current ! ; \ wordlist Vocabulary also previous 14may93py Variable slowvoc 0 slowvoc ! \ Forth-wordlist AConstant Forth-wordlist : mappedwordlist ( map-struct -- wid ) \ gforth \G Create a wordlist with a special map-structure. here swap A, 0 A, voclink @ A, 0 A, dup wordlist-link voclink ! dup initvoc ; : wordlist ( -- wid ) \ search \G Create a new, empty word list represented by wid. slowvoc @ IF \ this is now f83search because hashing may be loaded already \ jaw f83search ELSE Forth-wordlist wordlist-map @ THEN mappedwordlist ; : Vocabulary ( "name" -- ) \ gforth \G Create a definition "name" and associate a new word list with it. \G The run-time effect of "name" is to push the new word list's wid \G onto the top of the search order stack. Create wordlist drop DOES> context ! ; : also ( -- ) \ search ext \G Perform a DUP on the search order stack. Usually used prior \G to @code{Forth}, @code{definitions} etc. context @ vp @ 1+ dup maxvp > abort" Vocstack full" vp! context ! ; : previous ( -- ) \ search ext \G Perform a POP on the search order stack, thereby removing the wid at the \G top of the (search order) stack from the search order. vp @ 1- dup 0= abort" Vocstack empty" vp! ; \ vocabulary find 14may93py : (vocfind) ( addr count wid -- nfa|false ) \ !! generalize this to be independent of vp drop vp dup @ 1- cells over + DO 2dup I 2@ over <> IF (search-wordlist) dup IF nip nip UNLOOP EXIT THEN drop ELSE drop 2drop THEN [ -1 cells ] Literal +LOOP 2drop false ; 0 value locals-wordlist : (localsvocfind) ( addr count wid -- nfa|false ) \ !! use generalized (vocfind) drop locals-wordlist IF 2dup locals-wordlist (search-wordlist) dup IF nip nip EXIT THEN drop THEN 0 (vocfind) ; \ In the kernel the dictionary search works on only one wordlist. \ The following stuff builds a thing that looks to the kernel like one \ wordlist, but when searched it searches the whole search order \ (including locals) \ this is the wordlist-map of the dictionary Create vocsearch ( -- wordlist-map ) ' (localsvocfind) A, ' (reveal) A, ' drop A, ' drop A, \ create dummy wordlist for kernel slowvoc on vocsearch mappedwordlist \ the wordlist structure ( -- wid ) \ we don't want the dummy wordlist in our linked list 0 Voclink ! slowvoc off \ Only root 14may93py Vocabulary Forth \G ** this will not get annotated. See other defn below.. ** Vocabulary Root ( -- ) \ gforth \G Add the vocabulary @code{Root} to the search order stack. \G This vocabulary makes up the minimum search order and \G contains these words: @code{order} @code{set-order} \G @code{forth-wordlist} @code{Forth} @code{words} : Only ( -- ) \ search ext \G Set the search order to the implementation-defined minimum search \G order (for Gforth, this is the word list Root). 1 vp! Root also ; \ set initial search order 14may93py Forth-wordlist wordlist-id @ ' Forth >body wordlist-id ! 0 vp! also Root also definitions Only Forth also definitions lookup ! \ our dictionary search order becomes the law ( -- ) ' Forth >body to Forth-wordlist \ "forth definitions get-current" and "forth-wordlist" should produce the same wid \ get-order set-order 14may93py : get-order ( -- widn .. wid1 n ) \ search \G Copy the search order stack to the data stack. The current search \G order has n entries, of which wid1 represents the word \G list that is searched first (the word list at the top of the stack) and \G widn represents the word order that is searched last. vp @ 0 ?DO vp cell+ I cells + @ LOOP vp @ ; : set-order ( widn .. wid1 n -- ) \ search \G ** this will not get annotated. See other defn below.. ** \G If n=0, empty the search order. \G If n=-1, set the search order to the implementation-defined minimum search \G order (for Gforth, this is the word list Root). Otherwise, replace the \G existing search order with the n wid entries such that wid1 represents the \G word list that will be searched first and widn represents the word list that \G will be searched last. dup -1 = IF drop Only exit THEN dup vp! ?dup IF 1- FOR vp cell+ I cells + ! NEXT THEN ; : seal ( -- ) \ gforth \G Remove all word lists from the search order stack other than the word \G list that is currently on the top of the search order stack. context @ 1 set-order ; : .voc body> >head name>string type space ; : order ( -- ) \ search-ext \G ** this will not get annotated. See other defn below.. ** \G Print the search order and the compilation word list. The \G word lists are printed in the order in which they are searched. \G (which is reversed with respect to the conventional way of \G displaying stacks). The compilation word list is displayed last. \ The standard requires that the word lists are printed in the order \ in which they are searched. Therefore, the output is reversed \ with respect to the conventional way of displaying stacks. get-order 0 ?DO .voc LOOP 4 spaces get-current .voc ; : vocs ( -- ) \ gforth \G List vocabularies and wordlists defined in the system. voclink BEGIN @ dup WHILE dup 0 wordlist-link - .voc REPEAT drop ; Root definitions ' words Alias words ( -- ) \ tools \G Display a list of all of the definitions in the word list at the top \G of the search order. ' Forth Alias Forth ( -- ) \ search-ext \G PUSH the wid associated with @code{forth-wordlist} onto the search order stack. ' forth-wordlist alias forth-wordlist ( -- wid ) \ search \G CONSTANT: wid identifies the word list that includes all of the standard words \G provided by Gforth. When Gforth is invoked, this word list is the compilation word \G list and is at the top of the word list stack. ' set-order alias set-order ( widn .. wid1 n -- ) \ search \G If n=0, empty the search order. \G If n=-1, set the search order to the implementation-defined minimum search \G order (for Gforth, this is the word list Root). Otherwise, replace the \G existing search order with the n wid entries such that wid1 represents the \G word list that will be searched first and widn represents the word list that \G will be searched last. ' order alias order ( -- ) \ search-ext \G Print the search order and the compilation word list. The \G word lists are printed in the order in which they are searched. \G (which is reversed with respect to the conventional way of \G displaying stacks). The compilation word list is displayed last. Forth definitions