Use System/expansion for msfl

src/left.tal

@@ -1,6 +1,6 @@
 ( Left )
 
-|00 @System &vector $2 &wst $1 &rst $1 &pad $4 &r $2 &g $2 &b $2 &debug $1 &halt $1
+|00 @System &vector $2 &expansion $2 &wst $1 &rst $1 &metadata $2 &r $2 &g $2 &b $2 &debug $1 &state $1
 |10 @Console &vector $2 &read $1 &pad $4 &type $1 &write $1 &error $1
 |20 @Screen &vector $2 &width $2 &height $2 &auto $1 &pad $1 &x $2 &y $2 &addr $2 &pixel $1 &sprite $1
 |80 @Controller &vector $2 &button $1 &key $1
@@ -375,7 +375,7 @@
 	#0001 !mod-length
 
 @<cut-char> ( addr* -- )
-	get-eof #0001 <msfl>
+	#0001 <msfl>
 	#ffff
 	( >> )
 
@@ -384,7 +384,7 @@
 	reqdraw-textarea reqdraw-navbar #0a !<draw-state>
 
 @erase-selection ( -- )
-	get-from get-eof get-length STH2k <msfl>
+	get-from get-length STH2k <msfl>
 	update-nav #0000 STH2r SUB2 !mod-length
 
 @join-spaces ( addr* -- addr* )
@@ -1198,7 +1198,7 @@
 	[ LIT2 15 -Screen/auto ] DEO
 	get-scroll-addr
 	&>l ( -- )
-		draw-character LDAk #0a NEQ ?{
+		scan-state draw-character LDAk #0a NEQ ?{
 			<draw-lb>
 			.Screen/y DEI2 .Screen/height DEI2 #0010 SUB2 GTH2 ?&end
 			.scroll/x LDZ2 ;draw-character/anchor STA2 }
@@ -1216,7 +1216,7 @@
 	JMP2r
 
 @draw-character ( addr* -- addr* )
-	scan-state get-glyph-addr .Screen/addr DEO2
+	get-glyph-addr .Screen/addr DEO2
 	get-color ,&c STR
 	[ LIT2r &anchor $2 ] LITr -Screen/x DEO2kr
 	( | draw normal )
@@ -1543,14 +1543,13 @@
 		LDAk LDAkr STHr NEQ ?&>d
 	INC2 INC2r !&>l
 
-@<msfl> ( b* a* len* -- )
-	STH2
-	SWP2 EQU2k ?{
-		&>l ( -- )
-			DUP2k STH2kr ADD2 LDA ROT ROT STA
-			INC2 GTH2k ?&>l
-		POP2 POP2 }
-	POP2r JMP2r
+@<msfl> ( a* distance* -- )
+	OVR2 ,&dst STR2
+	ADD2k ,&src STR2
+	POP2 get-eof SWP2 SUB2 ,&length STR2
+	;&mmu .System/expansion DEO2
+	JMP2r
+	&mmu 01 &length 0000 0000 &src 0000 0000 &dst 0000
 
 @<msfr> ( b* a* len* -- )
 	STH2