get local, (non library) lua dependencies in tgf

dependanciesTGF.lua

-- this creates a Trivial Graph Format representaion of the 
-- require-based dependancies of the lua files in the current directory,
-- then saves it to <containing folder name>_deps.tgf

-- run in the directory you want to graph like this:
-- lua dependanciesTGF.lua

--requires Penlight

local file = require "pl.file"
local dir = require "pl.dir"
local path = require "pl.path"
local tablex = require "pl.tablex"
local stringio = require "pl.stringio"
local func = require "pl.func"

local fileList = dir.getfiles(".", "*.lua")

-- from http://lua-users.org/wiki/CommonFunctions
-- Lua pattern for matching Lua single line comment.
local pat_scomment = "(%-%-[^\n]*)"

-- Lua pattern for matching Lua multi-line comment.
local pat_mcomment = "(%-%-%[(=*)%[.-%]%2%])"

local nodes = stringio.create()
local edges = stringio.create()

local getRequireTarget = function(str) return string.match(str, "%./(.*)%.lua") end

local requireTargets = tablex.map(getRequireTarget, fileList)
local nodeIndicies = tablex.index_map (requireTargets)

tablex.foreachi (fileList, function(filename, index)
	nodes:write(index .. " " .. requireTargets[index] .. "\n")

	local contents = file.read(filename) .. "\n"
	contents = contents:gsub(pat_mcomment, "")
	contents = contents:gsub(pat_scomment, "")
	
	for line in contents:gmatch("[^\r\n]+") do
		local requireLine = line:match(".*require.-[^\r\n]+") or ""
		local requireTarget = requireLine:match("\"(.*)\"")
		
		if requireTarget then
      local sourceIndex = nodeIndicies[requireTargets[index]]
      local targetIndex = nodeIndicies[requireTarget]
      
      if sourceIndex and  targetIndex then 
        edges:write(sourceIndex .. " " .. targetIndex .. " " .. requireTarget .. "\n")
      end
      
		end
	end
	
end) 


local result = nodes:value() .. "#\n" .. edges:value()

print(file.write((path.currentdir() or ""):match("/([^/]-)$") .. "_deps.tgf", result))