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-- originally from http://lua-users.org/wiki/LuaXml
-- modified by me a bit
local function parseargs(s)
local arg = {}
string.gsub(s, "([%-%w]+)=([\"'])(.-)%2", function (w, _, a)
arg[w] = a
end)
return arg
end
local function tag(x)
return setmetatable(x, {__call=function(x, label)
-- search for child with given label
for _,c in ipairs(x) do
if c.label == label then
return c
end
end
return nil
end})
end
local psingle
local function pmulti(s, i, parent)
::again::
local nexti, child = psingle(s, i)
if child.close and child.label == parent.label then
return nexti, parent
else
table.insert(parent, child)
i = nexti
goto again
end
end
psingle = function(s, i)
i = i or 1
local ts,j,c,label,xarg,empty = s:find("<(%/?)([%w:]+)(.-)(%/?)>", i)
if not ts then
local rest = s:sub(i)
if rest:find("<",i) then
error('ill formed (eof?)')
elseif #rest == 0 then
error('empty string')
else
return i+#rest, rest
end
end
local nexti = j+1
local pretext = s:sub(i, ts-1)
if not pretext:find("^%s*$") then -- not entirely whitespace
return ts, pretext
end
if empty == "/" then
return nexti, tag{label=label, xarg=parseargs(xarg), empty=true}
elseif c == "" then -- start tag
return pmulti(s, nexti, tag{label=label, xarg=parseargs(xarg)})
else -- end tag
return nexti, tag{label=label, close=true}
end
end
local wrap
do
local _, cqa = pcall(require, 'cqueues.auxlib')
wrap = cqa and cqa.wrap or coroutine.wrap
end
local function stanzae(getmore)
return wrap(function()
local buf = ''
while true do
local ok, ni, el = pcall(psingle, buf)
if ok then
coroutine.yield(el)
buf = buf:sub(ni)
else
local more = getmore()
buf = buf .. more
end
end
end)
end
local entity_escapes = {
["<"]="<",
[">"]=">",
["&"]="&",
['"']=""",
["'"]="'"
}
local function escape(s)
return s:gsub("[<>&'\"]",entity_escapes)
end
local safestr_mt = {name='SAFESTR', __tostring=function(x) return x.s end}
local function safestr(s) return setmetatable({s=s}, safestr_mt) end
local function _xmlify(x)
if getmetatable(x) == safestr_mt then
return x
elseif type(x) == 'string' then
return safestr(escape(x))
elseif type(x) == 'table' then -- must be a tag
local function argstr(t)
local argstring = ''
for k,v in pairs(t) do
argstring = argstring .. (" %s='%s'"):format(k, _xmlify(v))
end
return argstring
end
if x.empty then
return safestr(("<%s%s/>"):format(x.label, argstr(x.xarg)))
else
local open = ("<%s%s>"):format(x.label, argstr(x.xarg))
local close = ("</%s>"):format(x.label)
local children = {}
for _,child in ipairs(x) do
table.insert(children, tostring(_xmlify(child)))
end
return safestr(open .. table.concat(children, '') .. close)
end
end
end
local function xmlify(...)
local n = select('#',...)
if n <= 1 then return _xmlify(...) end
local out = {}
for i = 1, n do
out[i] = tostring(_xmlify(select(i, ...)))
end
return table.concat(out, '\n')
end
-- dsl for input to xmlify. doesn't do escaping or anything.
-- THERE IS NO ESCAPE
local X = setmetatable({}, {__index=function(_,label)
return function(tab)
local out = {}
local xarg = {}
local empty = true
for k, v in pairs(tab) do
if type(k) == 'number' then -- child
empty = nil
out[k] = v
elseif type(k) == 'string' then -- attrib
xarg[k] = v
end
end
out.label = label
out.xarg = xarg
out.empty = empty
return out
end
end})
return { psingle = psingle, stanzae = stanzae, wrap=wrap, xmlify=xmlify, X=X }
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