feat(nix): add .split postfix to bindings

Author: TwIStOy

README.md

@@ -283,11 +283,17 @@ Snippets with `*` are available only when `vim_snippet` is enabled.
 ```scheme
 [
   (identifier)
-] @prefix
+] @identifier
+[
+((binding
+  expression: (_) @expr
+))
+] @binding
 ```
 
-| Trig  | Desc (placehoder: `?`)              | Expr before cursor |
-| :---: | ----------------------------------- | :----------------: |
-| `.on` | Expands to enable option statement. |     `any_expr`     |
+|   Trig   | Desc (placehoder: `?`)                  | Expr before cursor |
+| :------: | --------------------------------------- | :----------------: |
+|  `.on`   | Expands to enable option statement.     |    `identifier`    |
+| `.split` | Expands bindings to full attrset style. |     `binding`      |
 
 </details>

lua/luasnip-snippets/snippets/nix.lua

@@ -7,6 +7,8 @@ local rep = extras.rep
 local i = require("luasnip-snippets.nodes").insert_node
 local tsp = require("luasnip.extras.treesitter_postfix")
 local Utils = require("luasnip-snippets.utils")
+---@type luasnip-snippets.utils.treesitter
+local UtilsTS = require("luasnip-snippets.utils.treesitter")
 
 local identifier_query = [[
 [
@@ -40,6 +42,37 @@ local function identifier_tsp(trig, expand, dscr)
   })
 end
 
+local bind_query = [[
+[
+((binding
+  expression: (_) @expr
+)) 
+] @prefix
+]]
+
+---@param context LSSnippets.ProcessMatchesContext
+---@param previous any
+local function inject_bind_matches(context, previous)
+  vim.print("???")
+  local node = context.prefix_node
+  local attr_path = node:field("attrpath")[1]
+  local attrs_nodes = attr_path:field("attr")
+  local attrs = {}
+
+  for _, attr in ipairs(attrs_nodes) do
+    local attr_text = context.ts_parser:get_node_text(attr)
+    attrs[#attrs + 1] = attr_text
+  end
+
+  previous = vim.tbl_deep_extend("force", previous, {
+    env_override = {
+      ATTRS = attrs,
+    },
+  })
+
+  return previous
+end
+
 return {
   snippet {
     "@module",
@@ -76,4 +109,38 @@ return {
     "? = { enable = true; };",
     "Completes an identifier with an enable option"
   ),
+
+  UtilsTS.treesitter_postfix({
+    trig = ".split",
+    name = "(.split) foo.bar = xxx; -> foo = { bar = xxx; };",
+    dscr = "Split a dot expression into full attrset declaration",
+    wordTrig = false,
+    reparseBuffer = "live",
+    matchTSNode = {
+      query = bind_query,
+      query_lang = "nix",
+    },
+    injectMatches = inject_bind_matches,
+  }, {
+    f(function(_, parent)
+      vim.print(parent.snippet.env)
+      local attrs = parent.snippet.env.ATTRS
+      local expr = table.concat(parent.snippet.env.LS_TSCAPTURE_EXPR, "\n")
+      Utils.reverse_list(attrs)
+
+      local generate_bindings = function(first, attr, previous)
+        if first then
+          return ("%s = %s;"):format(attr, previous)
+        else
+          return ("%s = { %s };"):format(attr, previous)
+        end
+      end
+
+      for j, attr in ipairs(attrs) do
+        expr = generate_bindings(j == 1, attr, expr)
+      end
+
+      return expr
+    end, {}),
+  }),
 }