forth: allow DEFINE's ";" to be at the start of a newline

Previous to this commit, DEFINE's algo would miss a ";" right after a newline.

This allows for a much nicer formatting+comment of core.fs.

apps/forth/core.fs

@@ -20,13 +20,27 @@
   a reference to "," so that this word is written to HERE.
  
   NOT: a bit convulted because we don't have IF yet )
-: IF COMPILE SKIP? COMPILE (fbr) H 1 ALLOT ; IMMEDIATE
-( Subtract TOS from H to get offset to write to IF or ELSE's
-  br cell )
-: THEN DUP H -^ SWAP C! ; IMMEDIATE
-( write (fbr) addr, allot, then same as THEN )
-: ELSE
-    COMPILE (fbr) 1 ALLOT DUP H -^ SWAP C! H 1 - ; IMMEDIATE
+
+: IF                ( -- a | a: br cell addr )
+    COMPILE SKIP?   ( if true, don't branch )
+    COMPILE (fbr)
+    H               ( push a )
+    1 ALLOT         ( br cell allot )
+; IMMEDIATE
+
+: THEN              ( a -- | a: br cell addr )
+    DUP H -^ SWAP   ( a-H a )
+    C!
+; IMMEDIATE
+
+: ELSE              ( a1 -- a2 | a1: IF cell a2: ELSE cell )
+    COMPILE (fbr)
+    1 ALLOT
+    DUP H -^ SWAP   ( a-H a )
+    C!
+    H 1 -           ( push a. -1 for allot offset )
+; IMMEDIATE
+
 : ? @ . ;
 : VARIABLE CREATE 2 ALLOT ;
 : CONSTANT CREATE H ! DOES> @ ;

apps/forth/dict.asm

@@ -278,7 +278,7 @@ DEFINE:
 	ld	(HERE), hl
 .loop:
 	; did we reach ";"?
-	ld	hl, (INPUTPOS)
+	call	toword
 	ld	a, (hl)
 	cp	';'
 	jr	nz, .compile

apps/forth/util.asm

@@ -4,25 +4,35 @@ pad:
 	ld	a, PADDING
 	jp	addHL
 
+; Advance (INPUTPOS) until a non-whitespace is met. If needed,
+; call fetchline.
+; Set HL to newly set (INPUTPOS)
+toword:
+	ld	hl, (INPUTPOS)
+	; skip leading whitespace
+	dec	hl	; offset leading "inc hl"
+.loop:
+	inc	hl
+	ld	a, (hl)
+	or	a
+	; When at EOL, fetch a new line directly
+	jr	z, .empty
+	cp	' '+1
+	jr	c, .loop
+	ret
+.empty:
+	call	fetchline
+	jr	toword
+
 ; Read word from (INPUTPOS) and return, in HL, a null-terminated word.
 ; Advance (INPUTPOS) to the character following the whitespace ending the
 ; word.
 ; When we're at EOL, we call fetchline directly, so this call always returns
 ; a word.
 readword:
-	ld	hl, (INPUTPOS)
-	; skip leading whitespace
-	dec	hl	; offset leading "inc hl"
-.loop1:
-	inc	hl
-	ld	a, (hl)
-	or	a
-	; When at EOL, fetch a new line directly
-	jr	z, .empty
-	cp	' '+1
-	jr	c, .loop1
+	call	toword
 	push	hl		; --> lvl 1. that's our result
-.loop2:
+.loop:
 	inc	hl
 	ld	a, (hl)
 	; special case: is A null? If yes, we will *not* inc A so that we don't
@@ -30,7 +40,7 @@ readword:
 	or	a
 	jr	z, .noinc
 	cp	' '+1
-	jr	nc, .loop2
+	jr	nc, .loop
 	; we've just read a whitespace, HL is pointing to it. Let's transform
 	; it into a null-termination, inc HL, then set (INPUTPOS).
 	xor	a
@@ -40,9 +50,6 @@ readword:
 	ld	(INPUTPOS), hl
 	pop	hl		; <-- lvl 1. our result
 	ret	; Z set from XOR A
-.empty:
-	call	fetchline
-	jr	readword
 
 ; Sets Z if (HL) == E and (HL+1) == D
 HLPointsDE: