gistfile1.txt

{{
  : (`)
    dup 0 !if literal, which @ d->class @ compile ;then
    drop tib >number literal, ['] .data compile ;
---reveal---
  : '' ; immediate
  : `` repeat ' dup ['] '' =if drop ;then (`) again ; immediate
}}

: ::    ( -a )  here ] ;   
: vars for variable next ;

: stub  ( "- )  create 0 , 0 , 9 , ['] .word last @ d->class ! ;
: stubs ( n"- ) for stub next ;

 
4 stubs hook cursor scan-for-esc insert
4 stubs up down left right
 
: default:  ( "- )
  ' drop which @ d->xt @ 2 + compile ; immediate
 
::          ( -c )
 default: key dup 27 =if drop 32 ['] hook ['] key :is then ; 
is scan-for-esc
' scan-for-esc is key

 
: char: ( "-n ) 32 accept tib @ .data ; immediate

:: default: key
 cursor
 dup 27 =if ['] scan-for-esc ['] key :is then
 dup char: i =if ia then
 drop 32 ;
is hook
: assign: ` dup ` char: ` =if ' which @ d->class @ execute ` then ; immediate

:: ( n- ) 
 assign: h left
 assign: j down 
 assign: k up 
 assign: l right
 assign: i insert  ;
is cursor

3 vars x y insmode

stub hook
:: x -- hook ; is left
:: x ++ hook ; is right
:: y -- hook ; is up
:: y ++ hook ; is down
:: insmode @ if insmode off ;then insmode on ; is insert

: get-pos ( -a ) x @ y @ (line) + ;
:: ( - ) 43 get-pos ! v ; is hook
:: ( - ) get-pos dup . 32 emit @ cr ; is hook
:: ( - ) get-pos 0 (line) - . ; is hook

2 vars prior-pos prior-value
insmode on

:: ( - ) prior-pos @ 
         get-pos prior-pos !  ( save position before we write to it)
         get-pos @ prior-value !
         43 get-pos !         ( write to the position )
         insmode @ if
           prior-value @ swap ! ( restore prior value )
         then
         v ; is hook