chrisgrieser/nvim-spider

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pluginkeybindingmotionediting-support
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CREATED

2023-03-20

UPDATED

18 hours ago


nvim-spider 🕷️🕸️

Use the w, e, b motions like a spider. Move by subwords and skip insignificant punctuation.

A lua implementation of CamelCaseMotion, with extra consideration of punctuation. Works in normal, visual, and operator-pending mode. Supports counts and dot-repeat.

Features

The w, e, b (and ge) motions work the same as the default ones by vim, except for two differences:

Subword Motion

The movements happen by subwords, meaning it stops at the sub-parts of a camelCase, SCREAMING_SNAKE_CASE, or kebab-case variable.

-- positions vim's `w` will move to
local myVariableName = FOO_BAR_BAZ
--    ^              ^ ^

-- positions spider's `w` will move to
local myVariableName = FOO_BAR_BAZ
--    ^ ^       ^    ^ ^   ^   ^

Skipping Insignificant Punctuation

A sequence of one or more punctuation characters is considered significant if it is surrounded by whitespace and does not include any non-punctuation characters.

foo == bar .. "baz"
--  ^      ^    significant punctuation

foo:find("a")
-- ^    ^  ^  insignificant punctuation

This speeds up the movement across the line by reducing the number of mostly unnecessary stops.

-- positions vim's `w` will move to
if foo:find("%d") and foo == bar then print("[foo] has" .. bar) end
-- ^  ^^   ^  ^^  ^   ^   ^  ^   ^    ^    ^  ^  ^ ^  ^ ^  ^  ^ ^  -> 21

-- positions spider's `w` will move to
if foo:find("%d") and foo == bar then print("[foo] has" .. bar) end
-- ^   ^      ^   ^   ^   ^  ^   ^    ^       ^    ^    ^  ^    ^  -> 14

If you prefer to use this plugin only for subword motions, you can disable this feature by setting skipInsignificantPunctuation = false in the .setup() call.

[!NOTE] This plugin ignores vim's iskeyword option.

Installation

-- packer
use { "chrisgrieser/nvim-spider" }

-- lazy.nvim
{ "chrisgrieser/nvim-spider", lazy = true },

No keybindings are created by default. Below are the mappings to replace the default w, e, and b motions with this plugin's version of them.

vim.keymap.set(
    { "n", "o", "x" },
    "w",
    "<cmd>lua require('spider').motion('w')<CR>",
    { desc = "Spider-w" }
)
vim.keymap.set(
    { "n", "o", "x" },
    "e",
    "<cmd>lua require('spider').motion('e')<CR>",
    { desc = "Spider-e" }
)
vim.keymap.set(
    { "n", "o", "x" },
    "b",
    "<cmd>lua require('spider').motion('b')<CR>",
    { desc = "Spider-b" }
)

-- OR: lazy-load on keystroke
-- lazy.nvim
{
    "chrisgrieser/nvim-spider",
    keys = {
        {
            "e",
            "<cmd>lua require('spider').motion('e')<CR>",
            mode = { "n", "o", "x" },
        },
        -- ...
    },
},

[!NOTE] For dot-repeat to work, you have to call the motions as Ex-commands. When using function() require("spider").motion("w") end as third argument of the keymap, dot-repeatability will not work.

Configuration

The .setup() call is optional.

-- default values
require("spider").setup {
    skipInsignificantPunctuation = true,
    subwordMovement = true,
    customPatterns = {}, -- check "Custom Movement Patterns" in the README for details
}

You can also pass this configuration table to the motion function:

require("spider").motion("w", { skipInsignificantPunctuation = false })

Any options passed here will be used, and override the options set in the setup() call.

Advanced: Custom Movement Patterns

You can use the customPatterns table to define custom movement patterns. These must be lua patterns, and they must be symmetrical (work the same backwards and forwards) to work correctly with b and ge. If multiple patterns are given, the motion searches for all of them and stops at the closest one. When there is no match, the search continues in the next line.

If you have interesting ideas for custom patterns, please share them in the GitHub discussions, or make a PR to add them as built-in options.

A few examples:

-- The motion stops only at numbers.
require("spider").motion("w", {
    customPatterns = { "%d+" },
})

-- The motion stops at only at words with at least 3 chars or at any punctuation.
-- (Lua patterns have no quantifier like `{3,}`, thus the repetition.)
require("spider").motion("w", {
    customPatterns = { "%w%w%w+", "%p+" },
})

-- The motion stops only at hashes like `ef82a2`, avoiding repetition by using
-- `string.rep()`.
-- Extend default patterns by passing a `patterns` table and
-- setting `overrideDefault` to false.
require("spider").motion("w", {
    customPatterns = {
        patterns = {
            ("%x"):rep(6) .. "+" },
        },
        overrideDefault = false,
    },
})

-- The motion stops at the next declaration of a variable in -- javascript.
-- (The `e` motion combined with the `.` matching any character in
-- lua patterns ensures that you stop at beginning of the variable name.)
require("spider").motion("e", {
    customPatterns = { "const .", "let .", "var ." },
})

[!NOTE] The customPatterns option overrides nvim-spider's default behavior, meaning subword movement and skipping of punctuation are disabled. You can add customPatterns as an option to the .motion call to create new motions, while still having access nvim-spider's default behavior. Pass a patterns table and set overrideDefault to false to extend nvim-spider's default behavior with a new pattern.

Special Cases

UTF-8 support

For adding UTF-8 support for matching non-ASCII text, add luautf8 as rocks. You can do so directly in packer.nvim or via dependency on nvim_rocks in lazy.nvim.

-- packer
{ "chrisgrieser/nvim-spider", rocks = "luautf8" }

-- lazy.nvim
{
    "chrisgrieser/nvim-spider",
    lazy = true,
    dependencies = {
        "theHamsta/nvim_rocks",
        build = "pip3 install --user hererocks && python3 -mhererocks . -j2.1.0-beta3 -r3.0.0 && cp nvim_rocks.lua lua",
        config = function() require("nvim_rocks").ensure_installed("luautf8") end,
    },
},

Subword Text Object

This plugin supports w, e, and b in operator-pending mode, but does not include a subword variant of iw. For a version of iw that considers camelCase, check out the subword text object of nvim-various-textobjs.

Operator-pending Mode: The case of cw

In operator pending mode, vim's web motions are actually a bit inconsistent. For instance, cw will change to the end of a word instead of the start of the next word, like dw does. This is probably done for convenience in vi's early days before there were text objects. In my view, this is quite problematic since it makes people habitualize inconsistent motion behavior.

In this plugin, such small inconsistencies are therefore deliberately not implemented. Apart from the inconsistency, such a behavior can create unexpected results when used in subwords or near punctuation. If you nevertheless want to, you can achieve that behavior by mapping cw to ce:

vim.keymap.set("o", "w", "<cmd>lua require('spider').motion('w')<CR>")
vim.keymap.set("n", "cw", "ce", { remap = true })

-- or the same in one mapping without `remap = true`
vim.keymap.set("n", "cw", "c<cmd>lua require('spider').motion('e')<CR>")

Motions in Insert Mode

Simple and pragmatic: Wrap the normal mode motions in <Esc>l and i. (Drop the l on backwards motions.)

vim.keymap.set("i", "<C-f>", "<Esc>l<cmd>lua require('spider').motion('w')<CR>i")
vim.keymap.set("i", "<C-b>", "<Esc><cmd>lua require('spider').motion('b')<CR>i")

Credits

Thanks to @vypxl and @ii14 for figuring out dot-repeatability.

About the developer

In my day job, I am a sociologist studying the social mechanisms underlying the digital economy. For my PhD project, I investigate the governance of the app economy and how software ecosystems manage the tension between innovation and compatibility. If you are interested in this subject, feel free to get in touch.

I also occasionally blog about vim: Nano Tips for Vim