Diff for /gforth/look.fs between versions 1.7 and 1.22

version 1.7, 1997/03/27 13:31:02 version 1.22, 2003/01/04 08:26:57
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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 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
   
 decimal  require stuff.fs
   require environ.fs
   
 : PrimStart ['] true >name ;  decimal
   
 \ look                                                  17may93jaw  \ look                                                  17may93jaw
   
   \ rename to discover!!!
   
   : xt>threaded ( xt -- x )
   \G produces the threaded-code cell for the primitive xt
       threading-method 0= if
           @
       then ;
   
 : (look)  ( xt startlfa -- lfa flag )  : (look)  ( xt startlfa -- lfa flag )
         false swap      \ look up name of primitive with code at xt
         BEGIN @ dup      swap
         WHILE dup name>int      >r false swap
               3 pick = IF nip dup THEN      BEGIN
         REPEAT          @ dup
         drop nip      WHILE
         dup 0<> ;              dup name>int
               r@ = IF
                   nip dup
               THEN
       REPEAT
       drop rdrop
       dup 0<> ;
   
   : 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!
   [IFUNDEF] look
   has? ec [IF]
   
   has? rom 
   [IF]
   : prim>name ( xt -- nt flag )
       forth-wordlist @ (look) ;
   
   : look
       dup [ unlock rom-dictionary area lock ] 
       literal literal within
       IF
           >head-noprim dup ?? <>
       ELSE
           xt>threaded threaded>name
       THEN ;
   [ELSE]
   : look ( cfa -- lfa flag )
       >head-noprim dup ??? <> ;
   [THEN]
   
   [ELSE]
   
   : PrimStart ['] true >head-noprim ;
   
   : prim>name ( xt -- lfa flag )
       PrimStart (look) ;
   
 : look ( cfa -- lfa flag )  : look ( cfa -- lfa flag )
         dup dictionary-end forthstart within      dup in-dictionary?
         IF      IF
             PrimStart (look)          >head-noprim dup ??? <>
         ELSE      ELSE
             >name dup ??? <>          prim>name
         THEN ;      THEN ;
   
   [THEN]
   [THEN]
   
   : threaded>name ( ca -- lfa flag )
       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.1.7  
changed lines
  Added in v.1.22


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