Feature request: option for `w` and `b` to move by/select whole words instead of to the start of a new word.

I used this plugin on Kakoune and have found it more convenient than Kakoune’s normal behaviour. AFAIU, the plugin makes it such that the word navigation keys w and b move/select whole words (excluding trailing whitespaces) instead of moving to/selecting to the end/start of the current word (which is instead done with W and B, and which also excludes trailing whitespaces). It would be nice if there was an option to enable the same behaviour for Dance.

I’ve included some example expected behaviours if this hypothetical option was enabled in Dance. For each example, the first row is the buffer’s state before input, second is the input (in normal mode), and the third is the buffer’s state after the input. | is where the cursor is, [ and ] indicates the start and end of selection. These assume caret selection is enabled.

word_a wor|d_b word_c

w:

word_a [word_b]| word_c

word_a wor|d_b word_c

b:

word_a |[word_b] word_c

wor|d_a word_b word_c

ww:

word_a [word_b]| word_c

word_a word_b wor|d_c

bb:

word_a |[word_b] word_c

word_a wor|d_b word_c

W:

word_a wor[d_b]| word_c

word_a wor|d_b word_c

B:

word_a |[wor]d_b word_c

wor|d_a word_b word_c

WW:

wor[d_a word_b]| word_c

word_a word_b wor|d_c

BB:

word_a |[word_b wor]d_c

[71]

I think I know what the issue is. First of all, to search backwards you should use dance.search.backwards with input \\w (the input is a RegExp). Second of all, you can use dance.selections.{backward,forward} to change the direction of the selections.

{
  "key": "b",
  "command": "dance.run",
  "args": {
    "code": [
      "        const editor = vscode.window.activeTextEditor,",
      "              prev = editor.selections,",
      "              commands = [['.objects.performSelection', { object: 'word', action: 'select', inner: true }],",
      "                          ['.selections.backward']];",
      "",
      "        try {",
      "          await dance.execute(...commands);",
      "        } catch (e) {",
      "          if ((e?.message ?? '') !== 'no selections remaining') throw e;",
      "        }",
      "",
      "        if (editor.selections.every((x, i) => x.isEqual(prev[i]))) {",
      "          try {",
      "            await dance.execute(['.search.backwards', { input: '\\\\w' }], ...commands);",
      "          } catch (e) {",
      "            if ((e?.message ?? '') !== 'no selections remaining') throw e;",
      "          }",
      "        }"
    ]
  },
  "when": "editorTextFocus && dance.mode == 'normal'"
}

Unfortunately I did some debugging and no selections remaining still happens in that case and worse yet, it somehow prevents the code from working correctly. I have an idea of where the issue comes from (some off by one errors when handling selections that does not seem to happen in character mode) but I haven’t been able to fix it yet.

[71]

Looking at it, it looks like it’s implemented by invoking existing Kakoune commands. I spent some time trying to replicate this and some changes were needed, but in 0.4.2 you can have this kind of keybinding:

{
  "key": "w",
  "command": "dance.run",
  "args": {
    "code": [
      "const editor = vscode.window.activeTextEditor,",
      "      prev = editor.selections;",

      "try {",
      "  await dance.execute('.objects.performSelection', { object: 'word', action: 'select' });",
      "} catch (e) {",
      "  if ((e?.message ?? '') !== 'no selections remaining') throw e;",
      "}",

      "if (editor.selections.every((x, i) => x.isEqual(prev[i]))) {",
      "  await dance.execute(",
      "    ['.search', { input: '\\\\w' }],",
      "    ['.objects.performSelection', { object: 'word', action: 'select' }]);",
      "}",
    ],
  },
  "when": "editorTextFocus && dance.mode == 'normal'"
},

And similar keybindings with WbB (replacing the arguments of objects.performSelection as needed). Unfortunately there is a bug in the above code that will lead to “no selections remaining” being printed in some cases, but I haven’t found out why yet (and you can probably work around this).

In the future I’d like to make keybindings scriptable and to improve the scripting API, but for now this will have to do.