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local coroutine = coroutine;
local tonumber = tonumber;
local string = string;
local setmetatable, getmetatable = setmetatable, getmetatable;
local pairs = pairs;
local deadroutine = coroutine.create(function() end);
coroutine.resume(deadroutine);
module("lxp")
local entity_map = setmetatable({
["amp"] = "&";
["gt"] = ">";
["lt"] = "<";
["apos"] = "'";
["quot"] = "\"";
}, {__index = function(_, s)
if s:sub(1,1) == "#" then
if s:sub(2,2) == "x" then
return string.char(tonumber(s:sub(3), 16));
else
return string.char(tonumber(s:sub(2)));
end
end
end
});
local function xml_unescape(str)
return (str:gsub("&(.-);", entity_map));
end
local function parse_tag(s)
local name,sattr=(s):gmatch("([^%s]+)(.*)")();
local attr = {};
for a,b in (sattr):gmatch("([^=%s]+)=['\"]([^'\"]*)['\"]") do attr[a] = xml_unescape(b); end
return name, attr;
end
local function parser(data, handlers, ns_separator)
local function read_until(str)
local pos = data:find(str, nil, true);
while not pos do
data = data..coroutine.yield();
pos = data:find(str, nil, true);
end
local r = data:sub(1, pos);
data = data:sub(pos+1);
return r;
end
local function read_before(str)
local pos = data:find(str, nil, true);
while not pos do
data = data..coroutine.yield();
pos = data:find(str, nil, true);
end
local r = data:sub(1, pos-1);
data = data:sub(pos);
return r;
end
local function peek()
while #data == 0 do data = coroutine.yield(); end
return data:sub(1,1);
end
local ns = { xml = "http://www.w3.org/XML/1998/namespace" };
ns.__index = ns;
local function apply_ns(name, dodefault)
local prefix,n = name:match("^([^:]*):(.*)$");
if prefix and ns[prefix] then
return ns[prefix]..ns_separator..n;
end
if dodefault and ns[""] then
return ns[""]..ns_separator..name;
end
return name;
end
local function push(tag, attr)
ns = setmetatable({}, ns);
for k,v in pairs(attr) do
local xmlns = k == "xmlns" and "" or k:match("^xmlns:(.*)$");
if xmlns then
ns[xmlns] = v;
attr[k] = nil;
end
end
local newattr, n = {}, 0;
for k,v in pairs(attr) do
n = n+1;
k = apply_ns(k);
newattr[n] = k;
newattr[k] = v;
end
tag = apply_ns(tag, true);
ns[0] = tag;
ns.__index = ns;
return tag, newattr;
end
local function pop()
local tag = ns[0];
ns = getmetatable(ns);
return tag;
end
while true do
if peek() == "<" then
local elem = read_until(">"):sub(2,-2);
if elem:sub(1,1) == "!" or elem:sub(1,1) == "?" then -- neglect comments and processing-instructions
elseif elem:sub(1,1) == "/" then -- end tag
elem = elem:sub(2);
local name = pop();
handlers:EndElement(name); -- TODO check for start-end tag name match
elseif elem:sub(-1,-1) == "/" then -- empty tag
elem = elem:sub(1,-2);
local name,attr = parse_tag(elem);
name,attr = push(name,attr);
handlers:StartElement(name,attr);
name = pop();
handlers:EndElement(name);
else -- start tag
local name,attr = parse_tag(elem);
name,attr = push(name,attr);
handlers:StartElement(name,attr);
end
else
local text = read_before("<");
handlers:CharacterData(xml_unescape(text));
end
end
end
function new(handlers, ns_separator)
local co = coroutine.create(parser);
return {
parse = function(self, data)
if not data then
co = deadroutine;
return true; -- eof
end
local success, result = coroutine.resume(co, data, handlers, ns_separator);
if result then
co = deadroutine;
return nil, result; -- error
end
return true; -- success
end;
};
end
return _M;
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