feat: add buffer list (#30)

NOTE: Buffer entry sometimes uses unstyled window, and I can't figure out why.

* feat: add buffers

* fixup

lua/telescope/actions.lua

@@ -34,6 +34,7 @@ function actions.get_selected_entry(prompt_bufnr)
   return actions.get_current_picker(prompt_bufnr):get_selection()
 end
 
+-- TODO: It seems sometimes we get bad styling.
 local function goto_file_selection(prompt_bufnr, command)
   local picker = actions.get_current_picker(prompt_bufnr)
   local entry = actions.get_selected_entry(prompt_bufnr)
@@ -68,15 +69,28 @@ local function goto_file_selection(prompt_bufnr, command)
       col = tonumber(sections[3])
     end
 
-    vim.cmd(string.format([[bwipeout! %s]], prompt_bufnr))
+    local preview_win = state.get_status(prompt_bufnr).preview_win
+    if preview_win then
+      a.nvim_win_set_config(preview_win, {style = ''})
+    end
 
-    a.nvim_set_current_win(picker.original_win_id or 0)
-    vim.cmd(string.format(":%s %s", command, filename))
+    actions.close(prompt_bufnr)
 
-    local bufnr = vim.api.nvim_get_current_buf()
-    a.nvim_buf_set_option(bufnr, 'buflisted', true)
-    if row and col then
-      a.nvim_win_set_cursor(0, {row, col})
+    local original_win_id = picker.original_win_id or 0
+    local entry_bufnr = entry.bufnr
+
+    -- TODO: Sometimes we open something with missing line numbers and stuff...
+    a.nvim_set_current_win(original_win_id)
+    if entry_bufnr then
+      a.nvim_win_set_buf(original_win_id, entry_bufnr)
+    else
+      vim.cmd(string.format(":%s %s", command, filename))
+
+      local bufnr = vim.api.nvim_get_current_buf()
+      a.nvim_buf_set_option(bufnr, 'buflisted', true)
+      if row and col then
+        a.nvim_win_set_cursor(0, {row, col})
+      end
     end
 
     vim.cmd [[stopinsert]]

lua/telescope/builtin.lua

@@ -22,6 +22,7 @@ local pickers = require('telescope.pickers')
 local sorters = require('telescope.sorters')
 local utils = require('telescope.utils')
 
+local filter = vim.tbl_filter
 local flatten = vim.tbl_flatten
 
 -- TODO: Support silver search here.
@@ -340,4 +341,26 @@ builtin.fd = function(opts)
   }):find()
 end
 
+-- TODO: This is partially broken, but I think it might be an nvim bug.
+builtin.buffers = function(opts)
+  opts = opts or {}
+
+  local buffers =  filter(function(b)
+    return
+      vim.api.nvim_buf_is_loaded(b)
+      and 1 == vim.fn.buflisted(b)
+
+  end, vim.api.nvim_list_bufs())
+
+  pickers.new(opts, {
+    prompt    = 'Buffers',
+    finder    = finders.new_table {
+      results = buffers,
+      entry_maker = make_entry.gen_from_buffer(opts)
+    },
+    previewer = previewers.vim_buffer.new(opts),
+    sorter    = sorters.get_norcalli_sorter(),
+  }):find()
+end
+
 return builtin

lua/telescope/make_entry.lua

@@ -169,4 +169,26 @@ function make_entry.gen_from_quickfix(opts)
   end
 end
 
+function make_entry.gen_from_buffer(opts)
+  return function(entry)
+    local bufnr_str = tostring(entry)
+    local bufname = vim.api.nvim_buf_get_name(entry)
+
+    if '' == bufname then
+      return nil
+    end
+
+    return {
+      valid = true,
+
+      value = bufname,
+      ordinal = bufnr_str .. " : " .. bufname,
+      display = bufnr_str .. " : " .. bufname,
+
+      bufnr = entry,
+      filename = bufname,
+    }
+  end
+end
+
 return make_entry