Diff for /gforth/look.fs between versions 1.8 and 1.26

version 1.8, 1997/07/06 14:29:33 version 1.26, 2003/03/09 15:16:50
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 \ LOOK.FS      xt -> lfa                               22may93jaw  \ LOOK.FS      xt -> lfa                               22may93jaw
   
 \ Copyright (C) 1995 Free Software Foundation, Inc.  \ Copyright (C) 1995,1996,1997,2000,2003 Free Software Foundation, Inc.
   
 \ This file is part of Gforth.  \ This file is part of Gforth.
   
Line 16 Line 16
   
 \ You should have received a copy of the GNU General Public License  \ You should have received a copy of the GNU General Public License
 \ along with this program; if not, write to the Free Software  \ along with this program; if not, write to the Free Software
 \ Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.  \ Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111, USA.
   
 \ Look checks first if the word is a primitive. If yes then the  \ Look checks first if the word is a primitive. If yes then the
 \ vocabulary in the primitive area is beeing searched, meaning  \ vocabulary in the primitive area is beeing searched, meaning
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 \ Problems: A compiled xt via compile, might be created with noname:  \ Problems: A compiled xt via compile, might be created with noname:
 \           a noname: leaves now a empty name field  \           a noname: leaves now a empty name field
   
   require stuff.fs
   require environ.fs
   
 decimal  decimal
   
 \ look                                                  17may93jaw  \ look                                                  17may93jaw
   
 \ rename to discover!!!  \ rename to discover!!!
   
 : (look)  ( xt startlfa -- lfa flag )  : xt>threaded ( xt -- x )
         false swap  \G produces the threaded-code cell for the primitive xt
         BEGIN @ dup      threading-method 0= if
         WHILE dup name>int          @
               3 pick = IF nip dup THEN      then ;
         REPEAT  
         drop nip  : search-name  ( xt startlfa -- nt|0 )
         dup 0<> ;      \ look up name of primitive with code at xt
       swap
       >r false swap
       BEGIN
           @ dup
       WHILE
               dup name>int
               r@ = IF
                   nip dup
               THEN
       REPEAT
       drop rdrop ;
   
   : threaded>xt ( ca -- xt|0 )
   \G For the code address ca of a primitive, find the xt (or 0).
       [IFDEF] decompile-prim
           decompile-prim
       [THEN]
        \ walk through the array of primitive CAs
       >r ['] noop begin
           dup @ while
               dup xt>threaded r@ = if
                   rdrop exit
               endif
               cell+
       repeat
       drop rdrop 0 ;
   
 \ !!! nicht optimal!  \ !!! nicht optimal!
 [IFUNDEF] look  [IFUNDEF] look
 [IFUNDEF] dictionary-end  has-rom [ELSE] false [THEN]  has? ec [IF]
   
   has? rom 
 [IF]  [IF]
   : prim>name ( xt -- nt|0 )
       forth-wordlist @ search-name ;
   
   : look ( xt -- lfa flag )
       dup [ unlock rom-dictionary area lock ] 
       literal literal within
       IF
           >head-noprim dup ?? <>
       ELSE
           prim>name dup 0<>
       THEN ;
   [ELSE]
 : look ( cfa -- lfa flag )  : look ( cfa -- lfa flag )
   forth-wordlist @ (look) ;      >head-noprim dup ??? <> ;
   [THEN]
   
 [ELSE]  [ELSE]
   
 : PrimStart ['] true >name ;  : PrimStart ['] true >head-noprim ;
   
 : look ( cfa -- lfa flag )  : prim>name ( xt -- nt|0 )
         dup dictionary-end forthstart within      PrimStart search-name ;
         IF  
             PrimStart (look)  : look ( xt -- lfa flag )
         ELSE      dup in-dictionary?
             >name dup ??? <>      IF
         THEN ;          >head-noprim dup ??? <>
       ELSE
           prim>name dup 0<>
       THEN ;
   
 [THEN]  [THEN]
 [THEN]  [THEN]
   
   : threaded>name ( ca -- nt|0 )
       threaded>xt prim>name ;
   
   : >head ( cfa -- nt|0 ) \ gforth to-head
       \G tries to find the name token nt of the word represented by cfa;
       \G returns 0 if it fails.  This word is not absolutely reliable,
       \G it may give false positives and produce wrong nts.
       look and ;
   
   ' >head ALIAS >name \ gforth to-name
   \G old name of @code{>head}

Removed from v.1.8  
changed lines
  Added in v.1.26


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