--- gforth/look.fs	2002/09/14 11:18:57	1.18
+++ gforth/look.fs	2007/12/31 19:02:24	1.29
@@ -1,12 +1,12 @@
 \ LOOK.FS      xt -> lfa                               22may93jaw
 
-\ Copyright (C) 1995,1996,1997,2000 Free Software Foundation, Inc.
+\ Copyright (C) 1995,1996,1997,2000,2003,2007 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
+\ as published by the Free Software Foundation, either version 3
 \ of the License, or (at your option) any later version.
 
 \ This program is distributed in the hope that it will be useful,
@@ -15,8 +15,7 @@
 \ 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., 59 Temple Place, Suite 330, Boston, MA 02111, USA.
+\ along with this program. If not, see http://www.gnu.org/licenses/.
 
 \ Look checks first if the word is a primitive. If yes then the
 \ vocabulary in the primitive area is beeing searched, meaning
@@ -41,19 +40,34 @@ decimal
 	@
     then ;
 
-: (look)  ( xt startlfa -- lfa flag )
-    false swap
+: search-name  ( xt startlfa -- nt|0 )
+    \ look up name of primitive with code at xt
+    swap
+    >r false swap
     BEGIN
 	@ dup
     WHILE
-	    dup name>int xt>threaded
-	    3 pick = IF
+	    dup name>int
+	    r@ = IF
 		nip dup
 	    THEN
     REPEAT
-    drop nip
-    dup 0<> ;
+    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!
 [IFUNDEF] look
@@ -61,13 +75,16 @@ has? ec [IF]
 
 has? rom 
 [IF]
-: look
+: 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
-	forth-wordlist @ (look)
+	prim>name dup 0<>
     THEN ;
 [ELSE]
 : look ( cfa -- lfa flag )
@@ -78,22 +95,29 @@ has? rom
 
 : PrimStart ['] true >head-noprim ;
 
-: look ( cfa -- lfa flag )
+: prim>name ( xt -- nt|0 )
+    PrimStart search-name ;
+
+: look ( xt -- lfa flag )
     dup in-dictionary?
     IF
 	>head-noprim dup ??? <>
     ELSE
-	PrimStart (look)
+	prim>name dup 0<>
     THEN ;
 
 [THEN]
 [THEN]
 
-: >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.
+: threaded>name ( ca -- nt|0 )
+    threaded>xt prim>name ;
+
+: >name ( xt -- nt|0 ) \ gforth to-name
+    \G tries to find the name token @var{nt} of the word represented
+    \G by @var{xt}; returns 0 if it fails.  This word is not
+    \G absolutely reliable, it may give false positives and produce
+    \G wrong nts.
     look and ;
 
-' >head ALIAS >name \ gforth to-name
-\G old name of @code{>head}
+' >name ALIAS >head \ gforth to-head
+\G another name of @code{>name}