Diff

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/tools/erlparse.lua	Sat Nov 29 23:59:27 2008 +0500
@@ -0,0 +1,130 @@
+
+local file = nil;
+local last = nil;
+local function read(expected)
+	local ch;
+	if last then
+		ch = last; last = nil;
+	else ch = file:read(1); end
+	if expected and ch ~= expected then error("expected: "..expected.."; got: "..(ch or "nil")); 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, __, _space = string.byte("AaZz09_ ", 1, 8);
+local function isAlpha(ch)
+	ch = string.byte(ch) or 0;
+	return (ch >= _A and ch <= _Z) or (ch >= _a and ch <= _z);
+end
+local function isNumeric(ch)
+	ch = string.byte(ch) or 0;
+	return (ch >= _0 and ch <= _9);
+end
+local function isVar(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 == __;
+end
+local function isSpace(ch)
+	ch = string.byte(ch) or "x";
+	return ch <= _space;
+end
+
+local function readString()
+	read("\""); -- skip quote
+	local slash = nil;
+	local str = "";
+	while true do
+		local ch = read();
+		if ch == "\"" and not slash then break; end
+		str = str..ch;
+	end
+	str = str:gsub("\\.", {["\\b"]="\b", ["\\d"]="\d", ["\\e"]="\e", ["\\f"]="\f", ["\\n"]="\n", ["\\r"]="\r", ["\\s"]="\s", ["\\t"]="\t", ["\\v"]="\v", ["\\\""]="\"", ["\\'"]="'", ["\\\\"]="\\"});
+	return str;
+end
+local function readSpecialString()
+	read("<"); read("<"); -- read <<
+	local str = "";
+	if peek() == "\"" then
+		local str = readString();
+	elseif peek() ~= ">" then
+		error();
+	end
+	read(">"); read(">"); -- read >>
+	return str;
+end
+local function readVar()
+	local var = read();
+	while isVar(peek()) do
+		var = var..read();
+	end
+	return var;
+end
+local function readNumber()
+	local num = read();
+	while isNumeric(peek()) do
+		num = num..read();
+	end
+	return tonumber(num);
+end
+local readItem = nil;
+local function readTuple()
+	local t = {};
+	read(); -- read { or [
+	while true do
+		local item = readItem();
+		if not item then break; end
+		table.insert(t, item);
+	end
+	read(); -- read } or ]
+	return t;
+end
+readItem = function()
+	local ch = peek();
+	if ch == nil then return nil end
+	if ch == "{" or ch == "[" then
+		return readTuple();
+	elseif isAlpha(ch) then
+		return readVar();
+	elseif isNumeric(ch) then
+		return readNumber();
+	elseif ch == "\"" then
+		return readString();
+	elseif ch == "<" then
+		return readSpecialString();
+	elseif isSpace(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;