Fixes #17

Added a new configuration option g:table_mode_corner_corner to
correspond to the extreme corners of the table border, by default it is
set to '|' to maintain backward compatibility but it can be overriden to
anything else.

autoload/tablemode.vim

@@ -4,7 +4,7 @@
 " Author:        Dhruva Sagar <http://dhruvasagar.com/>
 " License:       MIT (http://www.opensource.org/licenses/MIT)
 " Website:       http://github.com/dhruvasagar/vim-table-mode
-" Version:       3.3.2
+" Version:       3.3.3
 " Note:          This plugin was heavily inspired by the 'CucumberTables.vim'
 "                (https://gist.github.com/tpope/287147) plugin by Tim Pope.
 "
@@ -124,9 +124,9 @@ endfunction
 
 function! s:HeaderBorderExpr() "{{{2
   return s:StartExpr() .
-        \ '[' . g:table_mode_corner . g:table_mode_separator . ']' .
+        \ '[' . g:table_mode_corner . g:table_mode_corner_corner . ']' .
         \ '[' . g:table_mode_fillchar . g:table_mode_corner . ']*' .
-        \ '[' . g:table_mode_corner . g:table_mode_separator . ']' .
+        \ '[' . g:table_mode_corner . g:table_mode_corner_corner . ']' .
         \ s:EndExpr()
 endfunction
 
@@ -180,7 +180,7 @@ endfunction
 
 function! s:DefaultHeaderBorder() "{{{2
   if s:IsTableModeActive()
-    return g:table_mode_separator . g:table_mode_fillchar . g:table_mode_corner . g:table_mode_fillchar . g:table_mode_separator
+    return g:table_mode_corner_corner . g:table_mode_fillchar . g:table_mode_corner . g:table_mode_fillchar . g:table_mode_corner_corner
   else
     return ''
   endif
@@ -199,7 +199,7 @@ function! s:GenerateHeaderBorder(line) "{{{2
     if s:Strlen(line_val) <= 1 | return s:DefaultHeaderBorder() | endif
     let border = substitute(line_val[stridx(line_val, g:table_mode_separator):strridx(line_val, g:table_mode_separator)], g:table_mode_separator, g:table_mode_corner, 'g')
     let border = substitute(border, '[^' . g:table_mode_corner . ']', g:table_mode_fillchar, 'g')
-    let border = substitute(border, '^' . g:table_mode_corner . '\(.*\)' . g:table_mode_corner . '$', g:table_mode_separator . '\1' . g:table_mode_separator , '')
+    let border = substitute(border, '^' . g:table_mode_corner . '\(.*\)' . g:table_mode_corner . '$', g:table_mode_corner_corner . '\1' . g:table_mode_corner_corner, '')
 
     let cstartexpr = s:StartCommentExpr()
     if s:Strlen(cstartexpr) > 0 && getline(line) =~# cstartexpr
@@ -630,7 +630,10 @@ function! tablemode#GetFirstRow(line) "{{{2
 endfunction
 
 function! tablemode#TableizeInsertMode() "{{{2
-  if s:IsTableModeActive() && getline('.') =~# (s:StartExpr() . g:table_mode_separator)
+  if s:IsTableModeActive() && getline('.') =~# (s:StartExpr() . g:table_mode_separator . g:table_mode_separator)
+    call tablemode#AddHeaderBorder('.')
+    normal! A
+  elseif s:IsTableModeActive() && getline('.') =~# (s:StartExpr() . g:table_mode_separator)
     let column = s:Strlen(substitute(getline('.')[0:col('.')], '[^' . g:table_mode_separator . ']', '', 'g'))
     let position = s:Strlen(matchstr(getline('.')[0:col('.')], '.*' . g:table_mode_separator . '\s*\zs.*'))
     call tablemode#TableRealign('.')

doc/table-mode.txt

@@ -1,7 +1,7 @@
-*table-mode.txt*			Table Mode for easy table formatting. v3.3.2
+*table-mode.txt*		Table Mode for easy table formatting. v3.3.3
 ===============================================================================
 	Table Mode, THE AWESOME AUTOMATIC TABLE CREATOR & FORMATTER
-				 VERSION 3.3.2
+				 VERSION 3.3.3
 
 		Author: Dhruva Sagar <http://dhruvasagar.com/>
 		License: MIT <http://opensource.org/licenses/MIT/>
@@ -148,6 +148,8 @@ Overview:
 					current cell.
 	|table-mode-eval-expr-map| ...... Evaluate formula line and update
 					table.
+        |table-mode-corner-corner| ...... Set the character to be used for
+                                        extreme corners of the table border.
 
 g:loaded_table_mode					*table-mode-loaded*
 	Use this option to disable the plugin: >
@@ -277,6 +279,11 @@ g:table_mode_echo_cell_map                            *table-mode-echo-cell-map*
         representation for defining formulas. >
         	let g:table_mode_echo_cell_map = '?'
 <
+g:table_mode_corner_corner                           *table-mode-corner-corner*
+        Use this option to define the character to be used for the extreme
+        corners of the table border. >
+                let g:table_mode_corner_corner = '|'
+<
 
 ===============================================================================
 MAPPINGS						*table-mode-mappings*
@@ -332,9 +339,10 @@ MAPPINGS						*table-mode-mappings*
 		would evaluate the formula line and update the table
 		accordingly. This invokes the |TableEvalFormulaLine| command.
 
-||              Expands to a header border, the line immidiately above or
+||              Expands to a header border. You can change this by changing
-                below this will be considered as the table header. You can
+                |table-mode-separator| option. You can change the character to 
-              	change this by changing |table-mode-separator| options.
+                be used for te extreme corners of the border by changing
+                |table-mode-corner-corner| option.
 
 ===============================================================================
 COMMANDS						*table-mode-commands*

plugin/table-mode.vim

@@ -4,7 +4,7 @@
 " Author:        Dhruva Sagar <http://dhruvasagar.com/>
 " License:       MIT (http://www.opensource.org/licenses/MIT)
 " Website:       http://github.com/dhruvasagar/vim-table-mode
-" Version:       3.3.2
+" Version:       3.3.3
 " Note:          This plugin was heavily inspired by the 'CucumberTables.vim'
 "                (https://gist.github.com/tpope/287147) plugin by Tim Pope.
 "
@@ -51,6 +51,7 @@ call s:SetGlobalOptDefault('table_mode_delete_column_map', 'dc')
 call s:SetGlobalOptDefault('table_mode_add_formula_map', 'fa')
 call s:SetGlobalOptDefault('table_mode_eval_expr_map', 'fe')
 call s:SetGlobalOptDefault('table_mode_echo_cell_map', '?')
+call s:SetGlobalOptDefault('table_mode_corner_corner', '|')
 
 function! s:TableMotion() "{{{1
   let direction = nr2char(getchar())

t/tablemode.vim

@@ -14,6 +14,7 @@ let g:table_mode_delete_row_map = 'dd'
 let g:table_mode_delete_column_map = 'dc'
 let g:table_mode_add_formula_map = 'fa'
 let g:table_mode_eval_expr_map = 'fe'
+let g:table_mode_corner_corner = '|'
 
 call vspec#hint({'scope': 'tablemode#scope()', 'sid': 'tablemode#sid()'})