support other whitespace chars in word movements

Dependencies

• [2] MP2TBKU6 bugfix: crash in Text.up() after return
• [3] NUZFHX6I flesh out some tests for word movements
• [4] 62PZGSUC optimization: moving cursor to next word
• [5] ZPUQSPQP extract a few methods
• [6] DHI6IJCN selecting text and deleting selections
• [7] ZHLO7K3M add args to some functions
• [*] LXTTOB33 extract a couple of files
• [*] BULPIBEG beginnings of a module for the text editor
• [*] KECEMMMR extract couple of functions

Change contents

• edit in text_tests.lua at line 142
  [3.2609]

  [3.2609]
  + 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')
• edit in text_tests.lua at line 189
  [3.3807]

  [3.3807]
  + 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

  +
• replacement in text.lua at line 522
  [4.5061]→[2.598:668](∅→∅),[2.668]→[4.5131:5221](∅→∅),[4.5131]→[4.5131:5221](∅→∅)
  − local offset = Text.offset(Lines[Cursor1.line].data, Cursor1.pos)

  − assert(offset > 1)

  − if Lines[Cursor1.line].data:sub(offset-1,offset-1) == ' ' then
  [4.5061]

  [4.5221]
  + if Text.match(Lines[Cursor1.line].data, Cursor1.pos-1, '%s') then
• replacement in text.lua at line 532
  [4.5383]→[2.669:739](∅→∅),[2.739]→[4.10688:10784](∅→∅),[4.5453]→[4.10688:10784](∅→∅)
  − local offset = Text.offset(Lines[Cursor1.line].data, Cursor1.pos)

  − if Lines[Cursor1.line].data:sub(offset,offset) == ' ' then -- TODO: other space characters
  [4.5383]

  [4.5516]
  + if Text.match(Lines[Cursor1.line].data, Cursor1.pos, '%s') then
• edit in text.lua at line 539
  [11.42]

  [11.42]
  + 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)