1 files changed, 198 insertions, 0 deletions
diff --git a/tools/erlparse.lua b/tools/erlparse.lua
new file mode 100644
index 00000000..174585d3
--- /dev/null
+++ b/tools/erlparse.lua
@@ -0,0 +1,198 @@
+-- Prosody IM
+-- Copyright (C) 2008-2010 Matthew Wild
+-- Copyright (C) 2008-2010 Waqas Hussain
+-- 
+-- This project is MIT/X11 licensed. Please see the
+-- COPYING file in the source package for more information.
+--
+
+local string_byte, string_char = string.byte, string.char;
+local t_concat, t_insert = table.concat, table.insert;
+local type, tonumber, tostring = type, tonumber, tostring;
+
+local file = nil;
+local last = nil;
+local line = 1;
+local function read(expected)
+	local ch;
+	if last then
+		ch = last; last = nil;
+	else
+		ch = file:read(1);
+		if ch == "\n" then line = line + 1; end
+	end
+	if expected and ch ~= expected then error("expected: "..expected.."; got: "..(ch or "nil").." on line "..line); end
+	return ch;
+end
+local function pushback(ch)
+	if last then error(); end
+	last = ch;
+end
+local function peek()
+	if not last then last = read(); end
+	return last;
+end
+
+local _A, _a, _Z, _z, _0, _9, __, _at, _space, _minus = string_byte("AaZz09@_ -", 1, 10);
+local function isLowerAlpha(ch)
+	ch = string_byte(ch) or 0;
+	return (ch >= _a and ch <= _z);
+end
+local function isNumeric(ch)
+	ch = string_byte(ch) or 0;
+	return (ch >= _0 and ch <= _9) or ch == _minus;
+end
+local function isAtom(ch)
+	ch = string_byte(ch) or 0;
+	return (ch >= _A and ch <= _Z) or (ch >= _a and ch <= _z) or (ch >= _0 and ch <= _9) or ch == __ or ch == _at;
+end
+local function isSpace(ch)
+	ch = string_byte(ch) or "x";
+	return ch <= _space;
+end
+
+local escapes = {["\\b"]="\b", ["\\d"]="\127", ["\\e"]="\27", ["\\f"]="\f", ["\\n"]="\n", ["\\r"]="\r", ["\\s"]=" ", ["\\t"]="\t", ["\\v"]="\v", ["\\\""]="\"", ["\\'"]="'", ["\\\\"]="\\"};
+local function readString()
+	read("\""); -- skip quote
+	local slash = nil;
+	local str = {};
+	while true do
+		local ch = read();
+		if slash then
+			slash = slash..ch;
+			if not escapes[slash] then error("Unknown escape sequence: "..slash); end
+			str[#str+1] = escapes[slash];
+			slash = nil;
+		elseif ch == "\"" then
+			break;
+		elseif ch == "\\" then
+			slash = ch;
+		else
+			str[#str+1] = ch;
+		end
+	end
+	return t_concat(str);
+end
+local function readAtom1()
+	local var = { read() };
+	while isAtom(peek()) do
+		var[#var+1] = read();
+	end
+	return t_concat(var);
+end
+local function readAtom2()
+	local str = { read("'") };
+	local slash = nil;
+	while true do
+		local ch = read();
+		str[#str+1] = ch;
+		if ch == "'" and not slash then break; end
+	end
+	return t_concat(str);
+end
+local function readNumber()
+	local num = { read() };
+	while isNumeric(peek()) do
+		num[#num+1] = read();
+	end
+	if peek() == "." then
+		num[#num+1] = read();
+		while isNumeric(peek()) do
+			num[#num+1] = read();
+		end
+	end
+	return tonumber(t_concat(num));
+end
+local readItem = nil;
+local function readTuple()
+	local t = {};
+	local s = {}; -- string representation
+	read(); -- read {, or [, or <
+	while true do
+		local item = readItem();
+		if not item then break; end
+		if type(item) ~= "number" or item > 255 then
+			s = nil;
+		elseif s then
+			s[#s+1] = string_char(item);
+		end
+		t_insert(t, item);
+	end
+	read(); -- read }, or ], or >
+	if s and #s > 0  then
+		return t_concat(s)
+	else
+		return t
+	end;
+end
+local function readBinary()
+	read("<"); -- read <
+	-- Discard PIDs
+	if isNumeric(peek()) then
+		while peek() ~= ">" do read(); end
+		read(">");
+		return {};
+	end
+	local t = readTuple();
+	read(">") -- read >
+	local ch = peek();
+	if type(t) == "string" then
+		-- binary is a list of integers
+		return t;
+	elseif type(t) == "table" then
+		if t[1] then
+			-- binary contains string
+			return t[1];
+		else
+			-- binary is empty
+			return "";
+		end;
+	else
+		error();
+	end
+end
+readItem = function()
+	local ch = peek();
+	if ch == nil then return nil end
+	if ch == "{" or ch == "[" then
+		return readTuple();
+	elseif isLowerAlpha(ch) then
+		return readAtom1();
+	elseif ch == "'" then
+		return readAtom2();
+	elseif isNumeric(ch) then
+		return readNumber();
+	elseif ch == "\"" then
+		return readString();
+	elseif ch == "<" then
+		return readBinary();
+	elseif isSpace(ch) or ch == "," or ch == "|" then
+		read();
+		return readItem();
+	else
+		--print("Unknown char: "..ch);
+		return nil;
+	end
+end
+local function readChunk()
+	local x = readItem();
+	if x then read("."); end
+	return x;
+end
+local function readFile(filename)
+	file = io.open(filename);
+	if not file then error("File not found: "..filename); os.exit(0); end
+	return function()
+		local x = readChunk();
+		if not x and peek() then error("Invalid char: "..peek()); end
+		return x;
+	end;
+end
+
+module "erlparse"
+
+function parseFile(file)
+	return readFile(file);
+end
+
+return _M;