[ S" [" FIND >CFA , ]
EXIT
[ IMMEDIATE
+
+: IF IMMEDIATE
+ ' 0BRANCH ,
+ HERE @
+ 0 ,
+;
+
+: THEN IMMEDIATE
+ DUP
+ HERE @ SWAP -
+ SWAP !
+;
+
+: ELSE IMMEDIATE
+ ' BRANCH ,
+ HERE @
+ 0 ,
+ SWAP DUP HERE @ SWAP - SWAP !
+;
+
+: BEGIN IMMEDIATE
+ HERE @
+;
+
+: AGAIN IMMEDIATE
+ ' BRANCH ,
+ HERE @ - , ;
+
+: ( IMMEDIATE
+ BEGIN
+ READ-WORD
+ 1 = IF
+ C@ 41 = IF
+ EXIT
+ THEN
+ ELSE
+ DROP
+ THEN
+ AGAIN ;
+
+: UNTIL IMMEDIATE
+ ' 0BRANCH ,
+ HERE @ - ,
+;
+
+( Compile a literal value into the current word. )
+: LIT, IMMEDIATE ( x -- )
+ ' LIT , , ;
+
+: / /MOD DROP ;
+: MOD /MOD SWAP DROP ;
+: NEG 0 SWAP - ;
+
+: C,
+ HERE @ C!
+ HERE @ 1 +
+ HERE ! ;
+
+: OVER ( a b -- a b a ) SWAP DUP ROT ;
+
+( Compile the given string into the current word directly. )
+: STORE-STRING ( str len -- )
+ BEGIN
+ OVER C@ C,
+ SWAP 1 + SWAP
+ 1 - DUP 0 = UNTIL
+ DROP DROP ;
+
+: NEWLINE 10 EMIT ;
+: SPACE 32 EMIT ;
+
+( Read a number from standard input. )
+: READ-NUMBER READ-WORD PARSE-NUMBER ;
+
+( vim: syntax=forth
+)