get rid of all bifold text

It's just uneconomic to maintain given how little I've used it. I have a
bug right now and no time to port the bugfix to all the complexities of
the B side.

I briefly considered tossing out the entire source editor. But I _have_
been using it to browse logs across sessions. The live editor doesn't
quite cover all my use cases just yet.

We now have duplication in the source editor only for:
* syntax highlighting
* hyperlinking [[WikiWords]]
* ability to hide cursor (when showing file browser or Focus is in log browser)

source.lua

@@ -75,7 +75,7 @@ function source.initialize()
   love.window.setTitle('lines.love - source')
 end
 
--- environment for a mutable file of bifolded text
+-- environment for a mutable file
 -- TODO: some initialization is also happening in load_settings/initialize_default_settings. Clean that up.
 function source.initialize_edit_side()
   load_from_disk(Editor_state)
@@ -89,17 +89,12 @@ function source.initialize_edit_side()
   end
   edit.check_locs(Editor_state)
 
-  -- We currently start out with side B collapsed.
-  -- Other options:
-  --  * save all expanded state by line
-  --  * expand all if any location is in side B
   if Editor_state.cursor1.line > #Editor_state.lines then
     Editor_state.cursor1 = {line=1, pos=1}
   end
   if Editor_state.screen_top1.line > #Editor_state.lines then
     Editor_state.screen_top1 = {line=1, pos=1}
   end
-  edit.eradicate_locations_after_the_fold(Editor_state)
 
   if rawget(_G, 'jit') then
     jit.off()
@@ -253,13 +248,6 @@ end
 function source.quit()
   edit.quit(Editor_state)
   log_browser.quit(Log_browser_state)
-  -- convert any bifold files here
-end
-
-function source.convert_bifold_text(infilename, outfilename)
-  local contents = love.filesystem.read(infilename)
-  contents = contents:gsub('\u{1e}', ';')
-  love.filesystem.write(outfilename, contents)
 end
 
 function source.settings()

source_edit.lua

@@ -10,8 +10,6 @@ Highlight_color = {r=0.7, g=0.7, b=0.9}  -- selected text
 Icon_color = {r=0.7, g=0.7, b=0.7}  -- color of current mode icon in drawings
 Help_color = {r=0, g=0.5, b=0}
 Help_background_color = {r=0, g=0.5, b=0, a=0.1}
-Fold_color = {r=0, g=0.6, b=0}
-Fold_background_color = {r=0, g=0.7, b=0}
 
 Margin_top = 15
 Margin_left = 25
@@ -28,12 +26,10 @@ edit = {}
 -- run in both tests and a real run
 function edit.initialize_state(top, left, right, font_height, line_height)  -- currently always draws to bottom of screen
   local result = {
-    -- a line is either bifold text or a drawing
-    -- a line of bifold text consists of an A side and an optional B side
+    -- a line is either text or a drawing
+    -- a text is a table with:
     --    mode = 'text',
     --    string data,
-    --    string dataB,
-    --    expanded: whether to show B side
     -- a drawing is a table with:
     --    mode = 'drawing'
     --    a (y) coord in pixels (updated while painting screen),
@@ -50,7 +46,7 @@ function edit.initialize_state(top, left, right, font_height, line_height)  -- c
     -- Unless otherwise specified, coord fields are normalized; a drawing is always 256 units wide
     -- The field names are carefully chosen so that switching modes in midstream
     -- remembers previously entered points where that makes sense.
-    lines = {{mode='text', data='', dataB=nil, expanded=nil}},  -- array of lines
+    lines = {{mode='text', data=''}},  -- array of lines
 
     -- Lines can be too long to fit on screen, in which case they _wrap_ into
     -- multiple _screen lines_.
@@ -65,16 +61,15 @@ function edit.initialize_state(top, left, right, font_height, line_height)  -- c
     -- Given wrapping, any potential location for the text cursor can be described in two ways:
     -- * schema 1: As a combination of line index and position within a line (in utf8 codepoint units)
     -- * schema 2: As a combination of line index, screen line index within the line, and a position within the screen line.
-    -- Positions (and screen line indexes) can be in either the A or the B side.
     --
     -- Most of the time we'll only persist positions in schema 1, translating to
     -- schema 2 when that's convenient.
     --
     -- Make sure these coordinates are never aliased, so that changing one causes
     -- action at a distance.
-    screen_top1 = {line=1, pos=1, posB=nil},  -- position of start of screen line at top of screen
-    cursor1 = {line=1, pos=1, posB=nil},  -- position of cursor
-    screen_bottom1 = {line=1, pos=1, posB=nil},  -- position of start of screen line at bottom of screen
+    screen_top1 = {line=1, pos=1},  -- position of start of screen line at top of screen
+    cursor1 = {line=1, pos=1},  -- position of cursor
+    screen_bottom1 = {line=1, pos=1},  -- position of start of screen line at bottom of screen
 
     selection1 = {},
     -- some extra state to compute selection between mouse press and release
@@ -154,7 +149,7 @@ function edit.draw(State, hide_cursor)
     assert(false)
   end
   if not Text.le1(State.screen_top1, State.cursor1) then
-    print(State.screen_top1.line, State.screen_top1.pos, State.screen_top1.posB, State.cursor1.line, State.cursor1.pos, State.cursor1.posB)
+    print(State.screen_top1.line, State.screen_top1.pos, State.cursor1.line, State.cursor1.pos)
     assert(false)
   end
   State.cursor_x = nil
@@ -163,18 +158,14 @@ function edit.draw(State, hide_cursor)
 --?   print('== draw')
   for line_index = State.screen_top1.line,#State.lines do
     local line = State.lines[line_index]
---?     print('draw:', y, line_index, line, line.mode)
+--?     print('draw:', y, line_index, line)
     if y + State.line_height > App.screen.height then break end
-    State.screen_bottom1 = {line=line_index, pos=nil, posB=nil}
+    State.screen_bottom1 = {line=line_index, pos=nil}
     if line.mode == 'text' then
---?     print('text.draw', y, line_index)
-      local startpos, startposB = 1, nil
+--?       print('text.draw', y, line_index)
+      local startpos = 1
       if line_index == State.screen_top1.line then
-        if State.screen_top1.pos then
-          startpos = State.screen_top1.pos
-        else
-          startpos, startposB = nil, State.screen_top1.posB
-        end
+        startpos = State.screen_top1.pos
       end
       if line.data == '' then
         -- button to insert new drawing
@@ -192,7 +183,7 @@ function edit.draw(State, hide_cursor)
                      end,
         })
       end
-      y, State.screen_bottom1.pos, State.screen_bottom1.posB = Text.draw(State, line_index, y, startpos, startposB, hide_cursor)
+      y, State.screen_bottom1.pos = Text.draw(State, line_index, y, startpos, hide_cursor)
       y = y + State.line_height
 --?       print('=> y', y)
     elseif line.mode == 'drawing' then
@@ -255,10 +246,11 @@ function edit.mouse_press(State, x,y, mouse_button)
         State.old_cursor1 = State.cursor1
         State.old_selection1 = State.selection1
         State.mousepress_shift = App.shift_down()
-        local pos,posB = Text.to_pos_on_line(State, line_index, x, y)
-  --?       print(x,y, 'setting cursor:', line_index, pos, posB)
-        State.selection1 = {line=line_index, pos=pos, posB=posB}
---?         print('selection', State.selection1.line, State.selection1.pos, State.selection1.posB)
+        State.selection1 = {
+            line=line_index,
+            pos=Text.to_pos_on_line(State, line_index, x, y),
+        }
+--?         print('selection', State.selection1.line, State.selection1.pos)
         break
       end
     elseif line.mode == 'drawing' then
@@ -289,9 +281,11 @@ function edit.mouse_release(State, x,y, mouse_button)
       if line.mode == 'text' then
         if Text.in_line(State, line_index, x,y) then
 --?           print('reset selection')
-          local pos,posB = Text.to_pos_on_line(State, line_index, x, y)
-          State.cursor1 = {line=line_index, pos=pos, posB=posB}
---?           print('cursor', State.cursor1.line, State.cursor1.pos, State.cursor1.posB)
+          State.cursor1 = {
+              line=line_index,
+              pos=Text.to_pos_on_line(State, line_index, x, y),
+          }
+--?           print('cursor', State.cursor1.line, State.cursor1.pos)
           if State.mousepress_shift then
             if State.old_selection1.line == nil then
               State.selection1 = State.old_cursor1
@@ -360,11 +354,7 @@ function edit.keychord_press(State, chord, key)
       State.search_term = string.sub(State.search_term, 1, byte_offset-1)
       State.search_text = nil
     elseif chord == 'down' then
-      if State.cursor1.pos then
-        State.cursor1.pos = State.cursor1.pos+1
-      else
-        State.cursor1.posB = State.cursor1.posB+1
-      end
+      State.cursor1.pos = State.cursor1.pos+1
       Text.search_next(State)
     elseif chord == 'up' then
       Text.search_previous(State)
@@ -373,35 +363,10 @@ function edit.keychord_press(State, chord, key)
   elseif chord == 'C-f' then
     State.search_term = ''
     State.search_backup = {
-      cursor={line=State.cursor1.line, pos=State.cursor1.pos, posB=State.cursor1.posB},
-      screen_top={line=State.screen_top1.line, pos=State.screen_top1.pos, posB=State.screen_top1.posB},
+      cursor={line=State.cursor1.line, pos=State.cursor1.pos},
+      screen_top={line=State.screen_top1.line, pos=State.screen_top1.pos},
     }
     assert(State.search_text == nil)
-  -- bifold text
-  elseif chord == 'M-b' then
-    State.expanded = not State.expanded
-    Text.redraw_all(State)
-    if not State.expanded then
-      for _,line in ipairs(State.lines) do
-        line.expanded = nil
-      end
-      edit.eradicate_locations_after_the_fold(State)
-    end
-  elseif chord == 'M-d' then
-    if State.cursor1.posB == nil then
-      local before = snapshot(State, State.cursor1.line)
-      if State.lines[State.cursor1.line].dataB == nil then
-        State.lines[State.cursor1.line].dataB = ''
-      end
-      State.lines[State.cursor1.line].expanded = true
-      State.cursor1.pos = nil
-      State.cursor1.posB = 1
-      if Text.cursor_out_of_screen(State) then
-        Text.snap_cursor_to_bottom_of_screen(State, State.left, State.right)
-      end
-      schedule_save(State)
-      record_undo_event(State, {before=before, after=snapshot(State, State.cursor1.line)})
-    end
   -- zoom
   elseif chord == 'C-=' then
     edit.update_font_settings(State, State.font_height+2)
@@ -449,7 +414,7 @@ function edit.keychord_press(State, chord, key)
   -- clipboard
   elseif chord == 'C-a' then
     State.selection1 = {line=1, pos=1}
-    State.cursor1 = {line=#State.lines, pos=utf8.len(State.lines[#State.lines].data)+1, posB=nil}
+    State.cursor1 = {line=#State.lines, pos=utf8.len(State.lines[#State.lines].data)+1}
   elseif chord == 'C-c' then
     local s = Text.selection(State)
     if s then
@@ -524,20 +489,6 @@ function edit.keychord_press(State, chord, key)
   end
 end
 
-function edit.eradicate_locations_after_the_fold(State)
-  -- eradicate side B from any locations we track
-  if State.cursor1.posB then
-    State.cursor1.posB = nil
-    State.cursor1.pos = utf8.len(State.lines[State.cursor1.line].data)
-    State.cursor1.pos = Text.pos_at_start_of_screen_line(State, State.cursor1)
-  end
-  if State.screen_top1.posB then
-    State.screen_top1.posB = nil
-    State.screen_top1.pos = utf8.len(State.lines[State.screen_top1.line].data)
-    State.screen_top1.pos = Text.pos_at_start_of_screen_line(State, State.screen_top1)
-  end
-end
-
 function edit.key_release(State, key, scancode)
 end
 

text.lua

@@ -156,7 +156,6 @@ function Text.text_input(State, t)
   if State.cursor_y > App.screen.height - State.line_height then
     Text.populate_screen_line_starting_pos(State, State.cursor1.line)
     Text.snap_cursor_to_bottom_of_screen(State, State.left, State.right)
---?     print('=>', State.screen_top1.line, State.screen_top1.pos, State.cursor1.line, State.cursor1.pos, State.screen_bottom1.line, State.screen_bottom1.pos)
   end
   record_undo_event(State, {before=before, after=snapshot(State, State.cursor1.line)})
 end