support other whitespace chars in word movements

text.lua

@@ -519,9 +519,7 @@ function Text.word_left(left, right)
     Text.left(left, right)
     if Cursor1.pos == 1 then break end
     assert(Cursor1.pos > 1)
-    local offset = Text.offset(Lines[Cursor1.line].data, Cursor1.pos)
-    assert(offset > 1)
-    if Lines[Cursor1.line].data:sub(offset-1,offset-1) == ' ' then
+    if Text.match(Lines[Cursor1.line].data, Cursor1.pos-1, '%s') then
       break
     end
   end
@@ -531,8 +529,7 @@ function Text.word_right(left, right)
   while true do
     Text.right_without_scroll()
     if Cursor1.pos > utf8.len(Lines[Cursor1.line].data) then break end
-    local offset = Text.offset(Lines[Cursor1.line].data, Cursor1.pos)
-    if Lines[Cursor1.line].data:sub(offset,offset) == ' ' then  -- TODO: other space characters
+    if Text.match(Lines[Cursor1.line].data, Cursor1.pos, '%s') then
       break
     end
   end
@@ -541,6 +538,15 @@ function Text.word_right(left, right)
   end
 end
 
+function Text.match(s, pos, pat)
+  local start_offset = Text.offset(s, pos)
+  assert(start_offset)
+  local end_offset = Text.offset(s, pos+1)
+  assert(end_offset > start_offset)
+  local curr = s:sub(start_offset, end_offset-1)
+  return curr:match(pat)
+end
+
 function Text.left(left, right)
   assert(Lines[Cursor1.line].mode == 'text')
   if Cursor1.pos > 1 then

text_tests.lua

@@ -141,6 +141,17 @@ function test_skip_to_previous_word()
   check_eq(Cursor1.pos, 1, 'F - test_skip_to_previous_word')
 end
 
+function test_skip_past_tab_to_previous_word()
+  io.write('\ntest_skip_past_tab_to_previous_word')
+  App.screen.init{width=120, height=60}
+  Lines = load_array{'abc def\tghi'}
+  Cursor1 = {line=1, pos=10}  -- within third word
+  Margin_right = 0; Margin_width = Margin_left
+  App.draw()
+  App.run_after_keychord('M-left')
+  check_eq(Cursor1.pos, 9, 'F - test_skip_past_tab_to_previous_word')
+end
+
 function test_move_to_start_of_word_on_previous_line()
   io.write('\ntest_move_to_start_of_word_on_previous_line')
   App.screen.init{width=120, height=60}
@@ -175,6 +186,17 @@ function test_skip_to_next_word()
   check_eq(Cursor1.pos, 8, 'F - test_skip_to_next_word')
 end
 
+function test_skip_past_tab_to_next_word()
+  io.write('\ntest_skip_past_tab_to_next_word')
+  App.screen.init{width=120, height=60}
+  Lines = load_array{'abc\tdef'}
+  Cursor1 = {line=1, pos=1}  -- at the space between words
+  Margin_right = 0; Margin_width = Margin_left
+  App.draw()
+  App.run_after_keychord('M-right')
+  check_eq(Cursor1.pos, 4, 'F - test_skip_past_tab_to_next_word')
+end
+
 function test_move_past_end_of_word_on_next_line()
   io.write('\ntest_move_past_end_of_word_on_next_line')
   App.screen.init{width=120, height=60}