Initial commit of suggest-require. A simple library for finding modules to require.

suggest-require.lua

@@ -0,0 +1,149 @@
+
+-- This is a tiny library to discover which modules can be imported using
+-- `require`. It's intended to be included in an auto-complete system for Lua.
+
+-- Not sure if it works on a system without GNU find :/
+
+---
+-- Constants
+
+local SCAN_DIR_TEMPLATE, SCAN_DIR_SEP_PATTERN
+
+if package.config:sub(1, 1) == '/' then
+	-- On unix
+	SCAN_DIR_TEMPLATE   	= 'find -L "%s" -maxdepth 1 -mindepth 1 -print0'
+	SCAN_DIR_SEP_PATTERN	= '%z'
+else
+	-- On windows
+	SCAN_DIR_TEMPLATE   	= 'dir "%s" /b /ad'
+	SCAN_DIR_SEP_PATTERN	= '\n'
+end
+
+-- TODO: Improve Windows support
+-- TODO: Make sure works on MacOS.
+
+--------------
+-- Util
+
+local function get_module_paths (path_str)
+	-- TODO: Add support for alternative package.config
+
+	-- Error check
+	local path_str = path_str or package.path
+	assert(type(package.config) == 'string')
+	assert(type(path_str) == 'string')
+
+	-- Work work
+	local paths  =  {}
+	for path in path_str:gmatch '[^;]+' do
+		paths[#paths+1] = path
+	end
+	-- Return
+	return paths
+end
+
+local function get_modules_fitting_path (root_path, module_names)
+	assert(type(root_path) == 'string')
+	assert(type(module_names) == 'table')
+
+    -- Use `find` to find files in folders below the given matching.
+    local pfile   	= io.popen ('find -L "'..(root_path:match '^(.-)?' or root_path)..'" -type f -not -path \'*/\\.*\' -print0')
+    local list_str	= pfile:read '*all'
+                  	  pfile:close()
+    -- Construct a pattern for the expected path of possible modules.
+    local module_path_pattern = '^'
+                      .. root_path:gsub('[%^%(%)%.%[%]%*%+%-]', function (a) return '%' .. a end)
+                              :gsub('?', '(.+)')
+                      .. '$'
+    -- Look through the file list, and find importable modules.
+	for path in list_str:gmatch '[^%z]+' do
+
+		local matches  	= { path:match(module_path_pattern) }
+		local identical	= #matches > 0
+
+		for i = 1, #matches do  if matches[1] ~= matches[i] then
+			identical = false; break
+		end end
+
+
+		-- Check if match
+		if identical then
+			module_names[#module_names+1] = matches[1]:gsub('/', '.')
+		end
+	end
+end
+
+
+--------------
+-- Finding Module Names
+
+local function get_loaded_module_names ()
+	-- Get the names of modules already loaded.
+	local l = {}
+	for k in pairs(package.loaded) do  l[#l+1] = k  end
+	return l
+end
+
+local function get_module_names_from_path ()
+	local paths = get_module_paths(package.path)
+
+	local modules = {}
+	for _, path in pairs(paths) do
+		get_modules_fitting_path(path, modules)
+	end
+
+	return modules
+end
+
+local function get_c_module_names_from_path ()
+	local paths = get_module_paths(package.cpath)
+
+	local modules = {}
+	for _, path in pairs(paths) do
+		get_modules_fitting_path(path, modules)
+	end
+
+	return modules
+end
+
+local function get_available_module_names ()
+	assert(type(package) == 'table')
+
+	local names_loaded	= get_loaded_module_names()
+	local names_path  	= get_module_names_from_path()
+	local names_cpath 	= get_c_module_names_from_path()
+
+	--
+
+	-- Dedub and Sort
+	local dedub = {}
+	for i = 1, #names_loaded	do	dedub[names_loaded[i]]	= true  end
+	for i = 1, #names_path  	do	dedub[names_path[i]]  	= true  end
+	for i = 1, #names_cpath 	do	dedub[names_cpath[i]] 	= true  end
+	local module_names = {}
+	for name in pairs(dedub) do  module_names[#module_names+1] = name  end
+	table.sort(module_names)
+
+	-- Output assertions
+	assert(type(module_names) == 'table')
+	for i = 1, #module_names do
+		assert(type(module_names[i]) == 'string')
+	end
+
+	-- Return
+	return module_names
+end
+
+--------------
+
+if ... then
+	return get_available_module_names
+else
+	local names = get_available_module_names()
+	io.write 'Following modules are available: \n'
+	for _, module_name in ipairs(names) do
+		io.write ' -  '
+		io.write(module_name)
+		io.write '\n'
+	end
+end