VE: Add replace mode

The indicator is going to be empty most of the time and will be
emitted by the mode changer directly. That's going to the upper-right
corner and the status bar avoids emitting in that area.

blk/122

@@ -4,3 +4,7 @@
 
 'I' inserts text by calling the "I" command from the Block
 editor.
+
+'R' goes into replace mode at current cursor position.
+Following keystrokes replace current character and advance
+cursor. Press return to return to normal mode.

blk/126

@@ -1,13 +1,12 @@
 CREATE CMD 2 C, '$' C, 0 C,
-VARIABLE MODE VARIABLE MODEC
 : 0acc 0 ACC ! ;
 : acc@ ACC @ 1 MAX 0acc ;
 : num ACC @ SWAP _pdacc IF DROP ELSE ACC ! THEN ;
 : nspcs ( n -- , spit n space ) 0 DO SPC LOOP ;
 : aty 0 SWAP AT-XY ;
-: clrln DUP aty COLS nspcs aty ;
-: clrscr LINES 0 DO i clrln LOOP ;
-: status 0 clrln ." BLK" SPC BLK> ? SPC ACC ?
-    SPC EDPOS @ 64 /MOD . ',' EMIT . SPC MODEC C@ EMIT ;
+: clrscr LINES 0 DO i aty COLS nspcs LOOP ;
+: status 0 aty ." BLK" SPC BLK> ? SPC ACC ?
+    SPC EDPOS @ 64 /MOD . ',' EMIT . 10 nspcs ;
 : contents 3 aty BLK> @ LIST ;
 : selblk BLK@ contents ;
+: mode! ( c -- ) 63 0 AT-XY ;

blk/127

@@ -6,7 +6,7 @@
 : $g ACC @ selblk 0acc ;
 : $[ BLK> @ acc@ - selblk ;
 : $] BLK> @ acc@ + selblk ;
-: $I 3 1 AT-XY I contents ;
+: $I mode! 'I' EMIT 3 1 AT-XY I contents mode! SPC ;
 : $h -1 cmv ; : $l 1 cmv ; : $k -64 cmv ; : $j 64 cmv ;
 : $H 0acc EDPOS @ 0x3c0 AND EDPOS ! ;
 : $L 0acc EDPOS @ 0x3f OR EDPOS ! ;

blk/128

@@ -4,8 +4,12 @@
 : $W EDPOS @ BLK( + acc@ 0 DO
     BEGIN C@- WS? UNTIL BEGIN C@- WS? NOT UNTIL LOOP
     1+ BLK( - DUP 0< IF DROP 0 THEN EDPOS ! ;
-: handleM ( c -- f )
+: $R ( replace mode )
+    mode! 'R' EMIT
+    BEGIN setpos C< DUP 0xd = NOT IF
+        EDPOS @ _cpos C! 1 EDPOS +! BLK!! 0
+    THEN UNTIL mode! SPC contents ;
+: handle ( c -- f )
     DUP '0' '9' =><= IF num 0 EXIT THEN
     DUP CMD 2+ C! CMD FIND IF EXECUTE ELSE DROP THEN
     UPPER 'Q' = ;
-: modeM ['] handleM MODE ! 'M' MODEC C! ;

blk/129

@@ -7,7 +7,7 @@
     2 aty ." F: " FBUF bufp ;
 : c<over KEY DUP EMIT DUP 0x0a = IF DROP 0x0d THEN ;
 : VE ['] c<over 0x08 ( C< override ) RAM+ !
-    clrscr 0acc 0 EDPOS ! modeM contents
-    BEGIN status bufs setpos KEY MODE @ EXECUTE UNTIL
+    clrscr 0acc 0 EDPOS ! contents
+    BEGIN status bufs setpos KEY handle UNTIL
     0 0x08 RAM+ ! 19 aty ;