diff --git a/moonscript.lua b/moonscript.lua
index f201165..de9ccd4 100644
--- a/moonscript.lua
+++ b/moonscript.lua
@@ -6,12 +6,21 @@ require"lpeg"
 
 require"moonscript.compile"
 
+local function count_indent(str)
+	local sum = 0
+	for v in str:gmatch("[\t ]") do
+		if v == ' ' then sum = sum + 1 end
+		if v == '\t' then sum = sum + 4 end
+	end
+	return sum
+end
+
 local R, S, V, P = lpeg.R, lpeg.S, lpeg.V, lpeg.P
 local C, Ct = lpeg.C, lpeg.Ct
 
 local Space = S" \t"^0
-local Indent = S"\t"^0
 local Break = S"\n" + -1
+local Indent = C(S"\t "^0) / count_indent
 local ArgDelim = "," * Space
 
 local Name = C(R("az", "AZ", "__") * R("az", "AZ", "__")^0) * Space
@@ -51,8 +60,20 @@ function flatten(tbl)
 	return tbl
 end
 
-
 local build_grammar = wrap(function()
+	local err_msg = "Failed to compile, line:\n [%d] >> %s"
+	local line = 1
+	local function line_count(subject, pos, str)
+		for _ in str:gmatch("\n") do
+			line = line + 1
+		end
+		-- print(line, util.dump(str))
+		return true
+	end
+
+	local Space = lpeg.Cmt(Space, line_count)
+	local Break = lpeg.Cmt(Break, line_count)
+
 	local g = lpeg.P{
 		Block,
 		Block = Ct(Line^0),
@@ -62,25 +83,42 @@ local build_grammar = wrap(function()
 		Exp = Ct(Value * (FactorOp * Value)^0) / flatten,
 		Value = Funcall + Num + Name
 	}
-	return Space * g * Space * -1
+	return {
+		_g = Space * g * Space * -1,
+		match = function(self, str, ...)
+			local function get_line(num)
+				for line in str:gmatch("(.-)[\n$]") do
+					if num == 1 then return line end
+					num = num - 1
+				end
+			end
+
+			local tree = self._g:match(str, ...)
+			if not tree then
+				return nil, err_msg:format(line, get_line(line))
+			end
+			return tree
+		end
+	}
+	
 end)
 
 local grammar = build_grammar()
 
 local program = [[
-hello world nuts
-eat 232, 343
+if gogo bozango
+	print hello_world
 ]]
 -- print hi + world + 2342
 -- print 23424
 -- ]]
 
 
-local tree = grammar:match(program)
-if not tree then error("failed to compile") end
+local tree, err = grammar:match(program)
+if not tree then error(err) end
 
 print(util.dump(tree))
-print(compile.tree(tree))
+-- print(compile.tree(tree))
 
 local program2 = [[
 if something