added swap dart ternary functionalities

lua/swap_ternary.lua

@@ -0,0 +1,64 @@
+-- swap_ternary.lua
+
+local ts = require('vim.treesitter')
+local get_node_text = ts.get_node_text
+local ts_utils = require("nvim-treesitter.ts_utils") -- requires nvim-treesitter
+local parsers = require("nvim-treesitter.parsers")
+
+local M = {}
+
+local function get_ternary_node(node)
+	if not node then
+		return
+	end
+
+	if node:type() ~= "conditional_expression" then
+		node = node:parent()
+		return get_ternary_node(node)
+	end
+
+	return node
+end
+
+function M.swap_ternary()
+	local bufnr = vim.api.nvim_get_current_buf()
+	local lang = parsers.get_buf_lang(bufnr)
+
+	if not parsers.has_parser(lang) then
+		print("No treesitter parser for current language")
+		return
+	end
+
+	local node = ts_utils.get_node_at_cursor(0)
+	local ternary_node = get_ternary_node(node)
+
+	if not ternary_node then
+		return
+	end
+
+	local t_consequence = ternary_node:field("consequence")
+	local result = ""
+	local t_alternate = ternary_node:field("alternative")
+	for i = 1, #t_alternate do
+		local text = get_node_text(t_alternate[i], bufnr)
+		result = result .. text
+	end
+	result = result .. " : "
+	for i = 1, #t_consequence do
+		local text = get_node_text(t_consequence[i], bufnr)
+		result = result .. text
+	end
+
+	local t = {}
+	local lines = string.gmatch(result, "[^\r\n]+")
+	for line in lines do
+		table.insert(t, line)
+	end
+
+	-- replace the ternary with the swapped text
+	local start_row, start_col = t_consequence[1]:start()
+	local end_row, end_col = t_alternate[#t_alternate]:end_()
+	vim.api.nvim_buf_set_text(bufnr, start_row, start_col, end_row, end_col, t)
+end
+
+return M