How to pass an argument to a user command that contains a space

Question

I have a user command that grep-replaces files recursively using vimgrep and cfdo:

-- Grep
vim.api.nvim_create_user_command(
  'Grep',
  function(opts)
    if #opts.fargs < 1 then
      print("Usage: :Grep(!) <pattern> <filter?>, i.e. :Grep /my_string/g **/*, or :Grep! /my_string/my_replacement/g **/*")
      return
    end
    local pattern = opts.fargs[1]
    local filter = opts.fargs[2] or "**/*"
    local segmno = 1
    local searchpatt = nil
    local replpatt = nil
    local flags = nil
    for pattsegm in string.gmatch(pattern, "([^/]+)") do
      if segmno == 1 then
        searchpatt = pattsegm
      elseif segmno == 2 then
        if not opts.bang then
          flags = pattsegm
        else
          replpatt = pattsegm
        end
      elseif segmno == 3 then
        flags = pattsegm
      else
        break
      end
      segmno = segmno + 1
    end
    if searchpatt and flags and filter then
      vim.cmd(":vimgrep /" .. searchpatt .. "/" .. flags .. "j " .. filter)
      vim.cmd(":cw")
      vim.cmd(":.cc")
      if opts.bang and replpatt then
        vim.cmd(":cfdo %s/" .. searchpatt .. "/" .. replpatt .. "/" .. flags .. "e")
      end
    end
  end,
  { nargs = '*', bang = true }
)

This works all fine until I want to replace a pattern with something that has a space in it, because it will shift my arguments, such as:

:Grep! /my\_s*string/my replacement/g **/*

Obviously, opts.fargs[1] is only /my\_s*string/my instead of /my\_s*string/my replacement/g.

I tried wrapping the first argument into '...' without success. How can I pass an argument that contains spaces to the user command?

Answer 1

I rewrote the user command, so it doesn't require to escape spaces:

-- Grep
vim.api.nvim_create_user_command(
'Grep',
function(opts)
    local usage = "Usage: :Grep <regex> <filter?>, i.e. :Grep /my_string/g **/*, or :Grep! s/my_string/my_replacement/g **/*"
    if not opts.args or string.len(opts.args) < 1 then
        print(usage)
        return
    end
    local delim = string.sub(opts.args, 1, 1)
    if delim == "s" then
        delim = string.sub(opts.args, 2, 2)
    end
    local pargs = vim.split(opts.args, delim)
    if #pargs < 3 then
        print(usage)
        return
    end
    local searchpatt = pargs[2]
    if pargs[1] == "s" and #pargs < 4 then
        print(usage)
        return
    end
    local replpatt = nil
    local flags = nil
    local filter = ""
    if pargs[1] == "s" then
        if not opts.bang then
            print(usage)
            return
        end
        replpatt = pargs[3]
        local bridge = vim.split(pargs[4], " ")
        flags = bridge[1]
        filter = bridge[2] or ""
        for i = 5, #pargs do
            filter = filter .. delim.. pargs[i]
        end
    else
        if opts.bang then
            print(usage)
            return
        end
        local bridge = vim.split(pargs[3], " ")
        flags = bridge[1]
        filter = bridge[2] or ""
        for i = 4, #pargs do
            filter = filter .. delim .. pargs[i]
        end
    end
    -- print("d:" .. delim .. "\ns:" .. searchpatt .. "\nr:" .. (replpatt or "nil") .. "\nm:" .. flags .. "\nf:" .. filter)
    if searchpatt and flags and filter then
        vim.cmd(":vimgrep /" .. searchpatt .. "/" .. flags .. "j " .. filter)
        vim.cmd(":cw")
        vim.cmd(":.cc")
        if replpatt then
            vim.cmd(":cfdo %s/" .. searchpatt .. "/" .. replpatt .. "/" .. flags .. "e")
        end
    end
end,
{ nargs = '*', bang = true }
)

This thing is a beast. It now requires to provide a bang AND the leader s for the replace functionality. It reads the delimiter and splits accordingly, but it also recovers the filter variable which might contain delimiters.