forth: add word "UNTIL"

apps/forth/core.fs

@@ -3,11 +3,12 @@
 : +! SWAP OVER @ + SWAP ! ;
 : ALLOT HERE +! ;
 : C, H C! 1 ALLOT ;
-: BEGIN H ; IMMEDIATE
 : COMPILE ' ['] LITN EXECUTE ['] , , ; IMMEDIATE
+: BEGIN H ; IMMEDIATE
 : AGAIN COMPILE (bbr) H -^ C, ; IMMEDIATE
+: UNTIL COMPILE SKIP? COMPILE (bbr) H -^ C, ; IMMEDIATE
 : NOT 1 SWAP SKIP? EXIT 0 * ;
-: ( BEGIN LITS ) WORD SCMP NOT SKIP? AGAIN ; IMMEDIATE
+: ( BEGIN LITS ) WORD SCMP NOT UNTIL ; IMMEDIATE
 ( Hello, hello, krkrkrkr... do you hear me?
   Ah, voice at last! Some lines above need comments
   BTW: Forth lines limited to 64 cols because of default
@@ -17,7 +18,7 @@
   (bbr)) and then call LITN on it. However, LITN is an
   immediate and has to be indirectly executed. Then, write
   a reference to "," so that this word is written to HERE.
- 
+
   NOT: a bit convulted because we don't have IF yet )
 
 : IF                ( -- a | a: br cell addr )

apps/forth/dictionary.txt

@@ -91,6 +91,7 @@ SKIP?       f --            If f is true, skip the execution of the next atom.
                             Use this right before ";" and you're gonna have a
                             bad time.
 THEN        I:a --          *I* Set branching cell at a.
+UNTIL       f --            *I* Jump backwards to BEGIN if f is *false*.
 
 *** Parameter Stack ***
 DROP        a --