diff --git a/hello.moon b/hello.moon
index 15e826e..17819f4 100644
--- a/hello.moon
+++ b/hello.moon
@@ -1,3 +1,4 @@
 
-# hello
+hello = 343
+print hello
 
diff --git a/moon b/moon
new file mode 100755
index 0000000..dfe0b0d
--- /dev/null
+++ b/moon
@@ -0,0 +1,69 @@
+#!/usr/bin/lua
+
+module("moonscript", package.seeall)
+
+require "moonscript.parse"
+require "moonscript.compile"
+
+require "util"
+
+require "alt_getopt"
+
+local opts, ind = alt_getopt.get_opts(arg, "hto:", { help = "h" })
+
+local help = [[Usage: %s [options] file...
+
+    -h          Print this message
+	-t          Dump parse tree
+	-o fname    Write output to file
+]]
+
+function print_help(err)
+	if err then print("Error: "..err) end
+	print(help:format(arg[0]))
+	os.exit()
+end
+
+function read_file(fname)
+	local f = io.open(fname)
+	if not f then return nil end
+	return f:read("*a")
+end
+
+local files = {}
+for i = ind, #arg do
+	table.insert(files, arg[i])
+end
+
+if opts.h then print_help() end
+if #files == 0 then
+	print_help"Missing input file"
+end
+
+local fname = files[1]
+
+local file_str = read_file(fname)
+if not file_str then
+	print_help("Failed to find file `"..fname.."`")
+end
+
+local tree, err = parse.string(file_str)
+
+if not tree then
+	print("Parse error: "..err)
+	os.exit()
+end
+
+if opts.t then
+	print(dump.tree(tree))
+	os.exit()
+end
+
+local code = compile.tree(tree)
+if opts.o then
+	io.open(opts.o, "w"):write(code.."\n")
+else
+	print(code)
+end
+
+
diff --git a/moonscript.lua b/moonscript/parse.lua
similarity index 90%
rename from moonscript.lua
rename to moonscript/parse.lua
index e4ba0a8..c5c627b 100644
--- a/moonscript.lua
+++ b/moonscript/parse.lua
@@ -1,12 +1,12 @@
 
-module("moonscript", package.seeall)
+module("moonscript.parse", package.seeall)
 
 require"util"
 require"lpeg"
 
-require"moonscript.compile"
-require"moonscript.dump"
-require"moonscript.data"
+local compile = require"moonscript.compile"
+local dump = require"moonscript.dump"
+local data = require"moonscript.data"
 
 local Stack = data.Stack
 
@@ -34,7 +34,7 @@ local Num = C(R("09")^1) / tonumber * Space
 local FactorOp = lpeg.C(S"+-") * Space
 local TermOp = lpeg.C(S"*/%") * Space
 
-function wrap(fn)
+local function wrap(fn)
 	local env = getfenv(fi)
 
 	return setfenv(fn, setmetatable({}, {
@@ -52,13 +52,13 @@ function wrap(fn)
 	}))
 end
 
-function mark(name)
+local function mark(name)
 	return function(...)
 		return name, ...
 	end
 end
 
-function got(what)
+local function got(what)
 	return Cmt("", function(...)
 		print("++ got "..what)
 		return true
@@ -66,7 +66,7 @@ function got(what)
 end
 
 
-function flatten(tbl)
+local function flatten(tbl)
 	if #tbl == 1 then
 		return tbl[1]
 	end
@@ -171,6 +171,13 @@ end)
 
 local grammar = build_grammar()
 
+-- parse a string
+-- returns tree, or nil and error message
+function string(str)
+	local g = build_grammar()
+	return grammar:match(str)
+end
+
 
 local program = [[
 if two_dads
@@ -200,18 +207,6 @@ if true
 
 ]]
 
-
-local tree, err = grammar:match(program)
-if not tree then error(err) end
-
-if type(tree) == "table" then
-	-- dump.tree(tree)
-	-- print""
-	print(compile.tree(tree))
-else
-	print "nothing..."
-end
-
 local program3 = [[
 -- hello
 class Hello