2 files changed, 42 insertions, 20 deletions

diff --git a/.vim/lua/align/init.lua b/.vim/lua/align/init.lua
index bcb8437..5dcf7c0 100644
--- a/.vim/lua/align/init.lua
+++ b/.vim/lua/align/init.lua
@@ -52,7 +52,7 @@ function M.align_lines(pat, line1, line2, preview_ns, preview_bufnr)
         -- modify preview buffer
         if preview_bufnr ~= nil then
           local prefix = string.format('|%d| ', line1 + i - 1)
-          vim.api.nvim_buf_set_lines(preview_bufnr, preview_buf_line, preview_buf_line, 0, { prefix .. newline })
+          vim.api.nvim_buf_set_lines(preview_bufnr, preview_buf_line, preview_buf_line, false, { prefix .. newline })
           vim.api.nvim_buf_add_highlight(preview_bufnr, preview_ns, 'Substitute', preview_buf_line, #prefix + s, #prefix + s + #changeset[2])
           preview_buf_line = preview_buf_line + 1
         end
@@ -64,13 +64,13 @@ function M.align_lines(pat, line1, line2, preview_ns, preview_bufnr)
   if not preview_ns then
     -- exit if nothing was changed
     if #newlines == 0 then return error('nothing changed') end
-
     vim.api.nvim_buf_set_lines(bufnr, line1 - 1, line2, 0, newlines)
+    return 0
   end
 
-  -- return magic number when called as preview callback
   if preview_ns ~= nil then
-    return 2
+    -- open preview buffer only if there is more than a single line of change
+    return (#preview_buf_line > 1) and 2 or 1
   end
 end
 
diff --git a/.vim/lua/misc.lua b/.vim/lua/misc.lua
index 457aa3c..7d4fa31 100644
--- a/.vim/lua/misc.lua
+++ b/.vim/lua/misc.lua
@@ -47,28 +47,50 @@ function M.open_under_cursor(cmd, detect_cmd)
 end
 
 local function get_visual_selection()
-  local pos1 = vim.fn.getpos("'<")
-  local ln1, col1 = pos1[2], pos1[3]
-  local pos2 = vim.fn.getpos("'>")
-  local ln2, col2 = pos2[2], pos2[3]
-  local lines = vim.fn.getline(ln1, ln2)
+  local top = vim.fn.getpos("'<")
+  top = { ln = top[2], col = top[3] }
+  local bot = vim.fn.getpos("'>")
+  bot = { ln = bot[2], col = bot[3] }
+  local lines = vim.api.nvim_buf_get_lines(0, (top.ln - 1), bot.ln, false)
   if vim.opt.selection:get() == 'inclusive' then
-    lines[#lines] = lines[#lines]:sub(1,col2)
+    lines[#lines] = lines[#lines]:sub(1, bot.col)
   else
-    lines[#lines] = lines[#lines]:sub(1,col2-1)
+    lines[#lines] = lines[#lines]:sub(1, (bot.col -1))
   end
-  lines[1] = lines[1]:sub(col1)
-  return pos1, pos2, lines
+  lines[1] = lines[1]:sub(top.col)
+  return top, bot, lines
 end
 
-function M.sort_line()
-  local fn = vim.fn
-  local pos1, _, lines = get_visual_selection()
+function M.sort_lines(_, preview_ns, preview_bufnr)
+  local bufnr = vim.api.nvim_get_current_buf()
+
+  local top, bot, lines = get_visual_selection()
   for i=1, #lines do
-    local ln = pos1[2] + (i-1)
-    local line = fn.join(fn.sort(fn.split(lines[i], " ")))
-    line = fn.substitute(fn.getline(ln), lines[i], line, "")
-    vim.fn.setline(ln, line)
+    lines[i] = vim.fn.join(vim.fn.sort(vim.fn.split(lines[i], " ")))
+  end
+
+  if not preview_ns then
+    vim.api.nvim_buf_set_lines(bufnr, top.ln-1, bot.ln, false, lines)
+    vim.notify('no preview')
+    return 0
+  end
+
+  -- inccommand preview
+  if preview_ns ~= nil then
+    for i, line in ipairs(lines) do
+      vim.api.nvim_buf_set_extmark(bufnr, preview_ns, top.ln+i - 2, 0, {
+        hl_mode = 'combine',
+        virt_text_pos = 'overlay',
+        virt_text = {{line, 'Substitute'}},
+      })
+
+      if preview_bufnr ~= nil then
+        local prefix = string.format('|%d| ', top.ln + i - 1)
+        vim.api.nvim_buf_set_lines(preview_bufnr, i-1, -1, false, { prefix .. line })
+        vim.api.nvim_buf_add_highlight(preview_bufnr, preview_ns, 'Substitute', i, #prefix, #prefix+#line)
+      end
+    end
+    return (#lines > 1 and 2 or 1)
   end
 end