File:  [gforth] / gforth / search.fs
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Sun Mar 9 15:16:52 2003 UTC (16 years, 8 months ago) by anton
Branches: MAIN
CVS tags: v0-6-2, v0-6-1, v0-6-0, HEAD
updated copyright years

    1: \ search order wordset                                 14may93py
    2: 
    3: \ Copyright (C) 1995,1996,1997,1998,2000,2003 Free Software Foundation, Inc.
    4: 
    5: \ This file is part of Gforth.
    6: 
    7: \ Gforth is free software; you can redistribute it and/or
    8: \ modify it under the terms of the GNU General Public License
    9: \ as published by the Free Software Foundation; either version 2
   10: \ of the License, or (at your option) any later version.
   11: 
   12: \ This program is distributed in the hope that it will be useful,
   13: \ but WITHOUT ANY WARRANTY; without even the implied warranty of
   14: \ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   15: \ GNU General Public License for more details.
   16: 
   17: \ You should have received a copy of the GNU General Public License
   18: \ along with this program; if not, write to the Free Software
   19: \ Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111, USA.
   20: 
   21: require struct.fs
   22: 
   23: $10 Value maxvp		\ current size of search order stack
   24: $400 Value maxvp-limit	\ upper limit for resizing search order stack
   25: 0 AValue vp		\ will be initialized later (dynamic)
   26: 
   27: : get-current  ( -- wid ) \ search
   28:   \G @i{wid} is the identifier of the current compilation word list.
   29:   current @ ;
   30: 
   31: : set-current  ( wid -- )  \ search
   32:   \G Set the compilation word list to the word list identified by @i{wid}.
   33:   current ! ;
   34: 
   35: :noname ( -- addr )
   36:     vp dup @ cells + ;
   37: is context
   38: 
   39: : vp! ( u -- )
   40:     vp ! ;
   41: : definitions  ( -- ) \ search
   42:   \G Set the compilation word list to be the same as the word list
   43:   \G that is currently at the top of the search order.
   44:   context @ current ! ;
   45: 
   46: \ wordlist Vocabulary also previous                    14may93py
   47: 
   48: Variable slowvoc   0 slowvoc !
   49: 
   50: \ Forth-wordlist AConstant Forth-wordlist
   51: 
   52: : mappedwordlist ( map-struct -- wid )	\ gforth
   53: \G Create a wordlist with a special map-structure.
   54:   here swap A, 0 A, voclink @ A, 0 A,
   55:   dup wordlist-link voclink !
   56:   dup initvoc ;
   57: 
   58: : wordlist  ( -- wid ) \ search
   59:   \G Create a new, empty word list represented by @i{wid}.
   60:   slowvoc @
   61:   IF    \ this is now f83search because hashing may be loaded already
   62: 	\ jaw
   63: 	f83search 
   64:   ELSE  Forth-wordlist wordlist-map @   THEN
   65:   mappedwordlist ;
   66: 
   67: : Vocabulary ( "name" -- ) \ gforth
   68:   \G Create a definition "name" and associate a new word list with it.
   69:   \G The run-time effect of "name" is to replace the @i{wid} at the
   70:   \G top of the search order with the @i{wid} associated with the new
   71:   \G word list.
   72:   Create wordlist drop  DOES> context ! ;
   73: 
   74: : check-maxvp ( n -- )
   75:    dup maxvp-limit > -49 and throw
   76:    dup maxvp > IF
   77:       BEGIN  dup  maxvp 2* dup TO maxvp  <= UNTIL
   78:       vp  maxvp 1+ cells resize throw TO vp
   79:    THEN drop ;
   80: 
   81: : >order ( wid -- ) \ gforth to-order
   82:     \g Push @var{wid} on the search order.
   83:     vp @ 1+ dup check-maxvp vp! context ! ;
   84: 
   85: : also  ( -- ) \ search-ext
   86:   \G Like @code{DUP} for the search order. Usually used before a
   87:   \G vocabulary (e.g., @code{also Forth}); the combined effect is to push
   88:   \G the wordlist represented by the vocabulary on the search order.
   89:   context @ >order ;
   90: 
   91: : previous ( -- ) \ search-ext
   92:   \G Drop the wordlist at the top of the search order.
   93:   vp @ 1- dup 0= -50 and throw vp! ;
   94: 
   95: \ vocabulary find                                      14may93py
   96: 
   97: : (vocfind)  ( addr count wid -- nfa|false )
   98:     \ !! generalize this to be independent of vp
   99:     drop vp dup @ 1- cells over +
  100:     DO  2dup I 2@ over <>
  101:         IF  (search-wordlist) dup
  102: 	    IF  nip nip  UNLOOP EXIT
  103: 	    THEN  drop
  104:         ELSE  drop 2drop  THEN
  105:     [ -1 cells ] Literal +LOOP
  106:     2drop false ;
  107: 
  108: 0 value locals-wordlist
  109: 
  110: : (localsvocfind)  ( addr count wid -- nfa|false )
  111:     \ !! use generalized (vocfind)
  112:     drop locals-wordlist
  113:     IF 2dup locals-wordlist (search-wordlist) dup
  114: 	IF nip nip
  115: 	    EXIT
  116: 	THEN drop
  117:     THEN
  118:     0 (vocfind) ;
  119: 
  120: \ In the kernel the dictionary search works on only one wordlist.
  121: \ The following stuff builds a thing that looks to the kernel like one
  122: \ wordlist, but when searched it searches the whole search order
  123: \  (including locals)
  124: 
  125: \ this is the wordlist-map of the dictionary
  126: Create vocsearch ( -- wordlist-map )
  127: ' (localsvocfind) A, ' (reveal) A,  ' drop A, ' drop A,
  128: 
  129: \ create dummy wordlist for kernel
  130: slowvoc on
  131: vocsearch mappedwordlist \ the wordlist structure ( -- wid )
  132: 
  133: \ we don't want the dummy wordlist in our linked list
  134: 0 Voclink !
  135: slowvoc off
  136: 
  137: \ Only root                                            14may93py
  138: 
  139: Vocabulary Forth ( -- ) \ gforthman- search-ext
  140:   \G Replace the @i{wid} at the top of the search order with the
  141:   \G @i{wid} associated with the word list @code{forth-wordlist}.
  142: 
  143: 
  144: Vocabulary Root ( -- ) \ gforth
  145:   \G Add the root wordlist to the search order stack.  This vocabulary
  146:   \G makes up the minimum search order and contains only a
  147:   \G search-order words.
  148: 
  149: : Only ( -- ) \ search-ext
  150:   \G Set the search order to the implementation-defined minimum search
  151:   \G order (for Gforth, this is the word list @code{Root}).
  152:   1 vp! Root also ;
  153: 
  154: : update-image-order ( -- )
  155:     \ save search order here, let vp point there
  156:     here vp over vp @ 1+ cells
  157:     dup allot move
  158:     to vp ;
  159: 
  160: : init-vp  ( -- )
  161:     vp @ $10 max to maxvp
  162:     maxvp 1+ cells allocate throw
  163:     vp over vp @ 1+ cells move
  164:     TO vp ;
  165: 
  166: :noname
  167:    init-vp DEFERS 'cold ;
  168: IS 'cold
  169: 
  170: here 0 , to vp
  171: 
  172: init-vp Only Forth also definitions
  173: 
  174: \ set initial search order                             14may93py
  175: 
  176: Forth-wordlist wordlist-id @ ' Forth >body wordlist-id !
  177: 
  178: lookup ! \ our dictionary search order becomes the law ( -- )
  179: 
  180: ' Forth >body to Forth-wordlist \ "forth definitions get-current" and "forth-wordlist" should produce the same wid
  181: 
  182: 
  183: \ get-order set-order                                  14may93py
  184: 
  185: : get-order  ( -- widn .. wid1 n ) \ search
  186:   \G Copy the search order to the data stack. The current search order
  187:   \G has @i{n} entries, of which @i{wid1} represents the wordlist
  188:   \G that is searched first (the word list at the top of the search
  189:   \G order) and @i{widn} represents the wordlist that is searched
  190:   \G last.
  191:   vp @ 0 ?DO vp cell+ I cells + @ LOOP vp @ ;
  192: 
  193: : set-order  ( widn .. wid1 n -- ) \ gforthman- search
  194:     \G If @var{n}=0, empty the search order.  If @var{n}=-1, set the
  195:     \G search order to the implementation-defined minimum search order
  196:     \G (for Gforth, this is the word list @code{Root}). Otherwise,
  197:     \G replace the existing search order with the @var{n} wid entries
  198:     \G such that @var{wid1} represents the word list that will be
  199:     \G searched first and @var{widn} represents the word list that will
  200:     \G be searched last.
  201:     dup -1 = IF
  202: 	drop only exit
  203:     THEN
  204:     dup check-maxvp
  205:     dup vp!
  206:     ?dup IF 1- FOR vp cell+ I cells + !  NEXT THEN ;
  207: 
  208: : seal ( -- ) \ gforth
  209:   \G Remove all word lists from the search order stack other than the word
  210:   \G list that is currently on the top of the search order stack.
  211:   context @ 1 set-order ;
  212: 
  213: [IFUNDEF] .name
  214: : id. ( nt -- ) \ gforth
  215:     \G Print the name of the word represented by @var{nt}.
  216:     \ this name comes from fig-Forth
  217:     name>string type space ;
  218: 
  219: ' id. alias .id ( nt -- )
  220: \G F83 name for @code{id.}.
  221: 
  222: ' id. alias .name ( nt -- )
  223: \G Gforth <=0.5.0 name for @code{id.}.
  224: 
  225: [THEN]
  226: 
  227: : .voc ( wid -- ) \ gforth
  228: \G print the name of the wordlist represented by @var{wid}.  Can
  229: \G only print names defined with @code{vocabulary} or
  230: \G @code{wordlist constant}, otherwise prints @samp{???}.
  231:     dup >r wordlist-struct %size + dup head? if ( wid nt )
  232: 	dup name>int dup >code-address docon: = swap >body @ r@ = and if
  233: 	    id. rdrop exit
  234: 	endif
  235:     endif
  236:     drop r> body> >head-noprim id. ;
  237: 
  238: : order ( -- )  \  gforthman- search-ext
  239:   \G Print the search order and the compilation word list.  The
  240:   \G word lists are printed in the order in which they are searched
  241:   \G (which is reversed with respect to the conventional way of
  242:   \G displaying stacks). The compilation word list is displayed last.
  243:   \ The standard requires that the word lists are printed in the order
  244:   \ in which they are searched. Therefore, the output is reversed
  245:   \ with respect to the conventional way of displaying stacks.
  246:     get-order 0
  247:     ?DO
  248: 	.voc
  249:     LOOP
  250:     4 spaces get-current .voc ;
  251: 
  252: : vocs ( -- ) \ gforth
  253:     \G List vocabularies and wordlists defined in the system.
  254:     voclink
  255:     BEGIN
  256: 	@ dup
  257:     WHILE
  258: 	dup 0 wordlist-link - .voc
  259:     REPEAT
  260:     drop ;
  261: 
  262: Root definitions
  263: 
  264: ' words Alias words  ( -- ) \ tools
  265: \G Display a list of all of the definitions in the word list at the top
  266: \G of the search order.
  267: ' Forth Alias Forth
  268: ' forth-wordlist alias forth-wordlist ( -- wid ) \ search
  269:   \G @code{Constant} -- @i{wid} identifies the word list that includes all of the standard words
  270:   \G provided by Gforth. When Gforth is invoked, this word list is the compilation word
  271:   \G list and is at the top of the search order.
  272: ' set-order alias set-order
  273: ' order alias order
  274: 
  275: Forth definitions
  276: 

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