Luanti: Convert lua_api.md to the CudaText format for autocompletion

Luanti_lua_api_to_CudaText_ACP.lua

-- Copyright (C) SmallJoker 2022 - 2025
-- License: MIT

-- This script imports the lua_api.md file from Luanti/Minetest to CudaText for
-- auto-completion. Tested with LuaJIT and a Luanti 5.12.0-dev file.

-- Usage:
--   1. $ luajit THIS_SCRIPT.lua /path/to/lua_api.md
--   2. Append the generated file to $HOME/.config/cudatext/data/autocomplete/Lua.acp
--   3. Restart CudaText

local args = { ... }
assert(type(args[1]) == "string", "Arg #1: Need file path")

local ENTRIES_LIMIT = 9999 -- debugging
local SIG_PATTERN = "%*%s`(%l+)%.([%a_]+)([^`]*)`"

local file = io.open(args[1], "r")
local output = {}

local TABLE_WHITELIST = {
	core = true,
	math = true,
	--minetest = true, -- only for older API files
	string = true,
	table = true,
	vector = true,
}

local entries = {
	-- [signature] = { args, desc }
}

local line
local line_handled = true

while ENTRIES_LIMIT > 0 do
	-- Preserve line from previous iteration if needed
	if line_handled then
		line = file:read("*l")
		if not line then
			break -- end of file
		end
	end
	line_handled = true

	repeat -- breakable
		local s_table, s_field, s_args = line:match(SIG_PATTERN)
		if not s_field then
			break
		end
		if not TABLE_WHITELIST[s_table] then
			print("Unknown table: " .. s_table)
			break
		end
		local sig = s_table .. "." .. s_field
		-- table.func_tion(arg1, arg2)
		-- table.variable
		local sig_args = s_table .. "." .. s_field .. s_args
		local is_func = s_args:find('%(')
		local description = line:match("`:%s*(.+)")

		if not is_func and entries[sig] and entries[sig][1] then
			break -- already have a function signature, do not overwrite.
		end

		if description then
			-- * `table.field(arg1, arg2): Description`
			local fullstop = description:find("%.")
			while not fullstop do
				line = file:read("*l")
				-- Ignore lines with leading '*'
				local is_different = line:match("^%s*%*(.+)")
				if is_different then
					line_handled = false
					break
				end
				line = line:match("%s*(.*)%s*") -- trim spaces
				fullstop = line:find("%.")
				description = description .. " "
					.. (fullstop and line:sub(1, fullstop) or line)
			end
		else
			-- Description line
			line = file:read("*l")
			description = line:match("%s*%* (.+)")
			-- Avoid matching a subsequent new function/variable doc line
			local _, s_field2, _ = line:match(SIG_PATTERN)
			if s_field2 or not description then
				description = ""
				line_handled = false
			end
		end

		entries[sig] = { is_func and s_args, description }
		ENTRIES_LIMIT = ENTRIES_LIMIT - 1
	until true -- once
end

local output = {}
for k, v in pairs(entries) do
	if v[1] then
		table.insert(output, "function " .. k .. v[1] .. " |" .. v[2])
	else
		table.insert(output, "variable " .. k .. " |" .. v[2])
	end
end

entries = nil
table.sort(output)

--print(table.concat(output, '\n'))

local f_out_name = "00_out_Lua_acp_segment.txt"
do
	local f_out = io.open(f_out_name, "w")
	f_out:write(table.concat(output, '\n'))
end
print("Wrote to ", f_out_name)