VE: fix buffer overflow with 'f' and make 'H' and 'L' affect 'f'

Kinda proud of this one. Efficiently piggy-backing on the Block
Editor, keeping things simple, and yet, building power into the
editor.

blk/122

@@ -1,12 +1,16 @@
 'H' goes to the beginning of the line, 'L' to the end.
 
-'w' moves forward by a word. 'W' moves backward by a word.
+'w' moves forward by a word. 'b' moves backward by a word.
+'W' moves to end-of-word. 'B' moves backward to end-of-word.
 
 'I', 'F' and 'E' invoke the corresponding command from the
 Block Editor (B100). Refer to documentation there.
 
-'X' deletes "modifier" characters following cursor.
+'f' puts the contents of your previous cursor movement into the
+find buffer. If that movement was a forward movement, it brings
+the cursor back where it was. This allows for an efficient
+combination of movements and 'E'. For example, if you want to
+delete the next word, you type 'w', then 'f', then check your
+"F" buffer to be sure, then press 'E'.
 
-'R' goes into replace mode at current cursor position.
-Following keystrokes replace current character and advance
-cursor. Press return to return to normal mode.
+'X' deletes "modifier" characters following cursor.     (cont.)

blk/123

@@ -0,0 +1,4 @@
+'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/125

@@ -1,3 +1,3 @@
 '? UPPER NOT [IF] 33 LOAD+ [THEN] DROP ( B158 )
 -23 LOAD+ ( B102, block editor )
-1 4 LOADR+
+1 5 LOADR+

blk/126

@@ -1,4 +1,5 @@
 CREATE CMD 2 C, '$' C, 0 C,
+VARIABLE PREVPOS
 : 0acc 0 ACC ! ;
 : acc@ ACC @ 1 MAX 0acc ;
 : num ACC @ SWAP _pdacc IF DROP ELSE ACC ! THEN ;
@@ -10,3 +11,5 @@ CREATE CMD 2 C, '$' C, 0 C,
 : contents 3 aty BLK> @ LIST ;
 : selblk BLK@ contents ;
 : mode! ( c -- ) 63 0 AT-XY ;
+: pos! EDPOS @ PREVPOS !
+    1023 MIN DUP 0< IF DROP 0 THEN EDPOS ! ;

blk/127

@@ -1,7 +1,6 @@
 : setpos EDPOS @ 64 /MOD
     3 + ( header ) SWAP 3 + ( gutter ) SWAP AT-XY ;
-: pos+ EDPOS @ + 1024 MOD EDPOS ! ;
-: cmv ( n -- , char movement ) acc@ * pos+ ;
+: cmv ( n -- , char movement ) acc@ * EDPOS @ + pos! ;
 : $; 0acc ;
 : $g ACC @ selblk 0acc ;
 : $[ BLK> @ acc@ - selblk ;
@@ -11,5 +10,5 @@
 : $E E contents ;
 : $X acc@ X contents ;
 : $h -1 cmv ; : $l 1 cmv ; : $k -64 cmv ; : $j 64 cmv ;
-: $H 0acc EDPOS @ 0x3c0 AND EDPOS ! ;
-: $L 0acc EDPOS @ 0x3f OR EDPOS ! ;
+: $H 0acc EDPOS @ 0x3c0 AND pos! ;
+: $L 0acc EDPOS @ 0x3f OR pos! ;

blk/128

@@ -1,15 +1,12 @@
 : $w EDPOS @ BLK( + acc@ 0 DO
     BEGIN C@+ WS? UNTIL BEGIN C@+ WS? NOT UNTIL LOOP
-    1- BLK( - 1023 MIN EDPOS ! ;
+    1- BLK( - pos! ;
 : $W EDPOS @ BLK( + acc@ 0 DO
+    1+ BEGIN C@+ WS? NOT UNTIL BEGIN C@+ WS? UNTIL LOOP
+    2- BLK( - pos! ;
+: $b EDPOS @ BLK( + acc@ 0 DO
+    1- BEGIN C@- WS? NOT UNTIL BEGIN C@- WS? UNTIL LOOP
+    2+ BLK( - pos! ;
+: $B EDPOS @ BLK( + acc@ 0 DO
     BEGIN C@- WS? UNTIL BEGIN C@- WS? NOT UNTIL LOOP
-    1+ BLK( - DUP 0< IF DROP 0 THEN EDPOS ! ;
-: $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' = ;
+    1+ BLK( - pos! ;

blk/129

@@ -1,13 +1,13 @@
-: bufp ( buf -- )
-    DUP 64 + SWAP DO
-        i C@ DUP 0x20 < IF DROP 0x20 THEN EMIT
-    LOOP ;
-: bufs
-    1 aty ." I: " IBUF bufp
-    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 ! contents
-    BEGIN status bufs setpos KEY handle UNTIL
-    0 0x08 RAM+ ! 19 aty ;
-
+: $f EDPOS @ PREVPOS @ 2DUP = IF 2DROP EXIT THEN
+    2DUP > IF DUP pos! SWAP THEN
+    ( p1 p2, p1 < p2 ) OVER - 64 MIN ( pos len ) FBUF _zbuf
+    SWAP _cpos FBUF ( len src dst ) ROT MOVE ;
+: $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' = ;

blk/130

@@ -0,0 +1,13 @@
+: bufp ( buf -- )
+    DUP 64 + SWAP DO
+        i C@ DUP 0x20 < IF DROP 0x20 THEN EMIT
+    LOOP ;
+: bufs
+    1 aty ." I: " IBUF bufp
+    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 ! 0 PREVPOS ! contents
+    BEGIN status bufs setpos KEY handle UNTIL
+    0 0x08 RAM+ ! 19 aty ;
+