#!/usr/bin/env retro # A Block Editor I've written numerous block editors over the years. This is a new one that I'm planning to eventually use with Retro/Native. This presents a visual, (briefly) modal interface. 0---------1---------2---------3---------4---------5---------6--- | This is the new block editor! | * | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 0---------1---------2---------3---------4---------5---------6--- * #2 1:0 The horizontal rulers have column indicators, there are cursor position indicators (and the actual cursor location shows at the intersection). The bottom right has the current block number, line number, and column number. Key Bindings | Key | Action | | --- | ------------------------------ | | H | Save and select previous block | | S | Save and select next block | | h | Move cursor left | | t | Move cursor down | | n | Move cursor up | | s | Move cursor right | | i | Save the current block | | y | Reload the current block | | a | Edit text | | c | Move cursor to prior word | | r | Move cursor to next word | | 1 | Evaluate the current block | | x | Erase the current block | | q | Save the Blocks and Quit | The key bindings are oriented around the Dvorak keyboard layout which I use. The key map leverages an approach I stole from Samuel Falvo II's VIBE editor: the key handlers are words in the dictionary with a format like: editor:key<*> With the `*` being the key. # Configuration I define the number of blocks and the file to use. On the non hosted Retro systems the block file will be replaced by a block storage device. ~~~ #512 'BLOCKS const 'retro.blocks 'BLOCK-FILE s:const ~~~ # Variables I am keeping some data in variables. This will include the current block number, the current line, and the current row. ~~~ 'CurrentBlock var 'CurrentLine var 'CurrentCol var ~~~ # Buffers I have one memory region for the current block and a second one for the entire set of blocks. I keep the blocks in RAM for performance. ~~~ 'Block d:create #1025 allot 'Blocks d:create BLOCKS #1024 * allot ~~~ # Block File I/O This should be replaced with the block storage device once that is added to Nga. ~~~ :blocks:initialize (-) &Blocks #1024 BLOCKS * [ #32 over store n:inc ] times drop ; :block:write (-) &Blocks BLOCK-FILE file:open BLOCKS #1024 * [ over fetch over file:write &n:inc dip ] times file:close drop ; :block:read (-) &Blocks BLOCK-FILE file:open swap [ dup-pair file:read swap store &n:inc dip ] times file:close drop ; ~~~ These are used to load a block into the active buffer and copy it back to the full set. ~~~ {{ :current-block @CurrentBlock #1024 * &Blocks + ; :next [ n:inc ] bi@ ; :copy dup-pair fetch swap store ; ---reveal--- :block:select (n-) !CurrentBlock [ &Block buffer:set current-block #1024 [ fetch-next buffer:add ] times drop ] buffer:preserve ; :block:update (-) current-block &Block #1024 [ copy next ] times drop-pair ; }} ~~~ # Block Display This is fairly long, but mostly due to my desire to have a more complex display with column and cursor indicators. It should be pretty straightforward though. ~~~ :tty:clear (-) #27 c:put '[2J s:put #27 c:put '[0;0H s:put ; {{ :ruler '____0---------1---------2---------3 s:put '---------4---------5---------6--- s:put nl ; :pad-to-cur @CurrentCol dup [ sp ] times ; :pad-to-eol #64 swap - [ sp ] times ; :indicator '____ s:put pad-to-cur $* c:put pad-to-eol ; :block# $# c:put @CurrentBlock n:put ; :pos @CurrentLine n:put $: c:put @CurrentCol n:put ; :status block# sp pos nl dump-stack nl ; :current? I @CurrentLine eq? ; :left [ $* c:put ] &sp choose ; :format current? left '_|_ s:put call '_| s:put nl ; :line [ #64 [ fetch-next c:put ] times ] format ; :code &Block #16 [ line ] times drop ; ---reveal--- :block:display (-) tty:clear ruler code ruler indicator status ; }} ~~~ # The Editor Core ~~~ {{ :cursor ASCII:ESC c:put $[ c:put @CurrentLine #2 + n:put $; c:put @CurrentCol #5 + n:put $H c:put ; :handler c:get 'editor:key<_> [ #11 + store ] sip d:lookup dup n:-zero? [ d:xt fetch call ] [ drop ] choose ; ---reveal--- :edit blocks:initialize block:read #0 block:select 'stty_cbreak unix:system tty:clear repeat block:display cursor handler again ; }} ~~~ # The Rest # Key Handlers All of the actual work is done by the words that make up the key handlers. ~~~ {{ 'Tokens d:create #4097 allot ---reveal--- :editor:key<1> &Tokens #4096 [ #0 over store n:inc ] times drop &Heap [ &Tokens !Heap &Block #32 s:tokenize ] v:preserve [ dup s:length n:zero? [ drop ] [ interpret ] choose ] set:for-each ; }} :editor:key block:update @CurrentBlock n:dec #0 BLOCKS n:dec n:limit block:select tty:clear ; :editor:key block:update @CurrentBlock n:inc #0 BLOCKS n:dec #18 &nl times dump-stack n:limit block:select tty:clear ; :editor:key &CurrentLine v:dec &CurrentLine #0 #15 v:limit ; :editor:key &CurrentCol v:dec &CurrentCol #0 #63 v:limit ; :editor:key &CurrentCol v:inc &CurrentCol #0 #63 v:limit ; :editor:key &CurrentLine v:inc &CurrentLine #0 #15 v:limit ; {{ :cursor ASCII:ESC c:put $[ c:put @CurrentLine #2 + n:put $; c:put @CurrentCol #5 + n:put $H c:put ; ---reveal--- :editor:key cursor s:get @CurrentLine #64 * @CurrentCol + &Block + over s:length [ dup-pair &fetch dip store &n:inc bi@ ] times drop-pair #27 c:put '[2J s:put ; }} :editor:key block:update block:write ; :editor:key @CurrentBlock block:select ; :editor:key &Block #1024 [ #32 over store n:inc ] times drop ; :editor:key block:write 'stty_-cbreak unix:system #0 unix:exit ; ~~~ ~~~ {{ :limit (n-n) &Block dup #1024 + n:limit ; :fetch-prior (a-Ac) [ n:dec ] [ fetch ] bi ; :find-next-word @CurrentLine #63 * @CurrentCol + &Block + n:inc repeat fetch-next #32 -eq? 0; drop again ; :find-prior-word @CurrentLine #63 * @CurrentCol + &Block + n:dec repeat fetch-prior #32 -eq? 0; drop again ; :select-next (-) find-next-word n:dec limit &Block - #63 /mod !CurrentLine !CurrentCol ; :select-prior (-) find-prior-word n:inc limit &Block - #63 /mod !CurrentLine !CurrentCol ; ---reveal--- :editor:key select-prior ; :editor:key select-next ; }} ~~~ # Run It ~~~ edit ~~~