EXIT
[ IMMEDIATE
-: / /MOD DROP ;
-: MOD /MOD SWAP DROP ;
-: NEG 0 SWAP - ;
-
: IF IMMEDIATE
' 0BRANCH ,
HERE @
HERE @
;
+: AGAIN IMMEDIATE
+ ' BRANCH ,
+ HERE @ - , ;
+
+: ( IMMEDIATE
+ BEGIN
+ READ-WORD
+ 1 = IF
+ C@ 41 = IF
+ EXIT
+ THEN
+ ELSE
+ DROP
+ THEN
+ AGAIN ; ( Yay! We now have comments! )
+
: UNTIL IMMEDIATE
' 0BRANCH ,
HERE @ - ,
;
-: FIB
- 0 1
- 0
- BEGIN
- ROT
- DUP ROT +
- ROT ROT
+( Compile a literal value into the current word. )
+: LIT, IMMEDIATE ( x -- )
+ ' LIT , , ;
- 1 +
- DUP 4 PICK = UNTIL
- DROP SWAP DROP SWAP DROP
-;
+: / /MOD DROP ;
+: MOD /MOD SWAP DROP ;
+: NEG 0 SWAP - ;
: C,
HERE @ C!
HERE @ 1 +
HERE ! ;
-: OVER
- SWAP DUP ROT ;
+: OVER ( a b -- a b a ) SWAP DUP ROT ;
-: STORE-STRING
+( An alternative comment syntax. Reads until the end of the line. )
+: \ IMMEDIATE
+ BEGIN
+ KEY
+ 10 = UNTIL ;
+
+\ So far, S" has only worked in immediate mode, which is backwards -- actually,
+\ the main use-case of this is as a compile-time word. Let's fix that.
+: S" IMMEDIATE
+ ' LITSTRING ,
+ HERE @ 0 C, \ We will put the length here
+ 0
+ BEGIN
+ 1 +
+ KEY DUP C,
+ 34 = UNTIL
+ \ Remove final "
+ HERE @ 1 - HERE !
+ 1 -
+ SWAP C! ;
+
+( 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 ;
-S" HELLO-ADDR" CREATE
-S" Hello!" DUP ROT
-STORE-STRING
-: HELLO
- ' HELLO-ADDR LIT [ , ] TELL NEWLINE ;
+: NEWLINE 10 EMIT ;
+: SPACE 32 EMIT ;
-HELLO
+( Read a number from standard input. )
+: READ-NUMBER READ-WORD PARSE-NUMBER ;
-S" 10 FIB = " TELL
-10 FIB .U
-S" (Expected: 59)" TELL NEWLINE
+: RESTART S" Ready." TELL NEWLINE ;
+RESTART