Can I do this Ultisnips snippet in lua/luasnip

[pmurray17]

Hi,

Is it possible to do the following ultisnips code in lua/luasnip?

def dashes18():
snip.rv = '-' * (18 - len(t[1]))

snippet dc "Declare Cursor" b
DECLARE $1!p dashes18() CURSOR FOR
$0
FREE $1
endsnippet

The cursor name can be a max of 18 characters long so it prints 18 dashes when initially invoked and reduces by 1 every time I type a character.

I just use the dashes as I guide so I dont have to count the letters as I type.

Any guidance would be appreciated.

[L3MON4D3]

Hi :)

That's possible:

s("dc", fmt([[
    DECLARE {i1} {dashes18} CURSOR FOR
        {i0}
    FREE {i1}
]], {
    i1 = i(1, "", {key = "first"}),
    dashes18 = f(function(args)
        return ("-"):rep(18 - #args[1][1])
    end, k("first")),
    i0 = i(0)
}, {repeat_duplicates = true}))

You'll also have to set

ls.setup{
    update_events = "TextChangedI"
}

if you want to see the dashes update as you type

[pmurray17]

Beautiful, that works a treat, thank you.

Is there by anychance a way of removing any remaining dashes after leaving field 1?

DECLARE small_curs ------- CURSOR FOR

FREE small_curs

I can move the dashes to the line below and remove when finished but just looking to increase my knowledge of luasnip.

[L3MON4D3]

Oh, interesting!

You can do

s("dc", fmt([[
    DECLARE {i1}{dashes18} CURSOR FOR
        {i0}
    FREE {i1}
]], {
    i1 = i(1, "", {key = "first", node_callbacks = {
        [events.leave] = function(node)
            vim.schedule(function()
                node.parent.snippet:get_keyed_node("dashes"):set_text({""})
            end)
        end
    }}),
    dashes18 = f(function(args)
        return ("-"):rep(18 - #args[1][1])
    end, k("first"), {key = "dashes"}),
    i0 = i(0)
}, {repeat_duplicates = true}))

ie. manually clear the functionNode after jumping out of the i(1).

[pmurray17]

Brillant, does exactly what I wanted, thanks, never would have figured that out but will be useful for future snippets.