Module:Buffer/sandbox
--[[=============================
This Module was written by Alexander Zhikun He, also known as, User:Codehydro on the English Wikipedia
All methods were developed independently and any resemblance to other string buffer libraries would be coincidental.
Furthermore, many methods will not work when compiled by standard Lua libraries as they depend on behaviors unique to
the MediaMiki Scribunto mod, which, for example, has a getmetatable() method that always returns nil on non-tables.
https://www.mediawiki.org/wiki/Extension:Scribunto/Lua_reference_manual
Source code comments may be thin at some points because they are intended to be supplemented by the documentation page:
https://en.wikipedia.org/wiki/Module:Buffer/doc
Licensed under Creative Commons Attribution-ShareAlike 3.0 Unported License
https://en.wikipedia.org/wiki/Wikipedia:Text_of_Creative_Commons_Attribution-ShareAlike_3.0_Unported_License
https://en.wikipedia.org/wiki/Module:Buffer
https://en.wikipedia.org/wiki/User:Codehydro
============================= -- ]]
-- Performs type validation
local function Valid(v)
if v and v ~= true then --reject nil/boolean; faster than 2 type() comparisons
local str = tostring(v) --functions not filtered since unlikely passed by accident (Scribunto does not have userdata/thread types)
--tostring(string-type) returns same ref; same refs compare faster than type()
if str ~= v and str == 'table' then
return rawget(v, 1) and table.concat(v)
end
--numbers are coerced to string per table.concat op; appending in string form saves ops on repeat concat
if str ~= '' then
return str
end
end
end
local MBpairs
local noOp = function() end
do
local iMap, vMap, oMap, pIter, pOther, pFast, Next --Map
local function init() -- init = noOp after first run
function Next(t)
return next, t -- slightly faster to do this than to use select()
end
function pIter(t, k)
-- don't use rawget; accepting unmapped tables does not measurably affect performance.
k = (iMap[t] or MBpairs(t, true) and iMap[t])[not k and 1 or vMap[t][k]]
return k, t[k]
end
function pOther(t, k)
-- comparison to nil because false is a valid key
k = (oMap[t] or MBpairs(t, true) and oMap[t])[nil==k and 1 or vMap[t][k]]
return k, t[k]
end
function pFast(t, k)
-- mapless iterator; almost as fast as native ipairs; slight performance penalty when length not cached
k = not k and 1 or k < (vMap[t] or #t) and k + 1 or nil
return k, t[k]
end
local mk = {__mode = 'k'} -- use mode 'k'; found that mode 'kv' sometimes garbage collects maps mid-loop (may not error because iterators auto re-map, but that's expensive)
init = noOp
iMap = setmetatable({}, mk) -- numeric keys
vMap = setmetatable({}, mk) -- next key
oMap = setmetatable({}, mk) -- non-numeric keys
end
function MBpairs(t, ...) -- pairs always iterates in order
local iter, ex = ...
init()
iter = iter == nil
if iter and not oMap[t] and ex==nil and rawget(t, 1)~=nil and next(t, #t)==nil then--while possible to miss keys, more thorough check would negate the benefit of pFast
vMap[t] = #t return pFast, t, nil
elseif ... or not vMap[t] or select('#', ...) ~= 1 then
local ti, tn, to, n = {}, {}, {}, #t --reduces table lookups
iMap[t], vMap[t], oMap[t] = ti, tn, to
for k = 1, n do
--stage one avoids number type checking op in stage two for most numeric keys
ti[k], tn[k] = k, k + 1
end
for k in (ex or Next)(t) do
if not tn[k] then
table.insert(tonumber(k) ~= k and to or ti, k)
end
end
if #ti ~= n then
table.sort(ti)
for k = 1, #ti do
-- somewhat wasteful, but trying to avoid overwriting can be even more expensive
tn[ti[k]] = k + 1
end
end
for k = 1, #to do
tn[to[k]] = k + 1
end
end
return iter and pIter or oMap[t] and pOther or noOp, t --noOp for mapless
end
end
local parent, rawkey, spec
do
--new scope for variables not reused outside (reduces number of var names that need to checked outside of scope)
--shared meta for Buffer parent property, raw mode, and specialized functions
local mkv = {
__mode = 'kv',
__call = function(t,k,v)
t[k] = v
return k
end
}
--shared meta less memory
parent = setmetatable({}, mkv)
rawkey = setmetatable({}, mkv)
spec = setmetatable({}, mkv)
end
local MB, MBi, MBmix, buffHTML, gfuncs, noCache, Element
do
--minimize number of locals per scope to reduce time spent sifting through irrelevant variable names
local _stream
do
local stream --keep stream near top of scope
local function init(f) --init = noOp after first run
local function each(self, ...)
for k = 1, select('#', ...) do
k = Valid(select(k, ...)) -- slightly faster than table.insert(self, (Valid(select(k, ...))))
if k then
table.insert(self, k)
end
end
return self
end
init = noOp
stream = {
__call = function(t, v)
v = v and Valid(v)
--last_concat cleared before entering stream mode
return v and table.insert(t, v) or t
end,
__index = function(t, i)
--no table look up minimizes resources to retrieve the only stream function
return i == 'each' and each or MB.__index(t, i) and setmetatable(t, MB)[i]
end,
__tostring = function(t)
return setmetatable(t, MB)()
end
}
for k, v in next, MB do
stream[k] = stream[k] or v
end
setmetatable(stream, getmetatable(MB))
end
function _stream(self, ...)
init()
self.last_concat = nil
return setmetatable(self, stream):each(...)
end
end
-- helper for :getParent()-like methods (including getBuffer which does not return a parent)
local function isMBfunc(Buffer, s, ...)
--eventually should figure out to make this work for :getHTML which is very similar
return s and
(
select('#', ...) == 0 and
(
--unprefixed function names append as a string
not rawkey[s] and
tostring(s):match('^_.*') and
MB.__index(Buffer, s) and
MB.__index(Buffer, s)(Buffer) or
MBmix(Buffer, s)
) or assert( --getParent is a one-way trip so one-time assert not expensive
MB.__index(Buffer, s),
('" %s " does not match any available Module:Buffer function'):format(s)
)(Buffer, ...)
) or Buffer
end
-- helper for :_out and :_str
local function MBselect(n, ...)
local n, seps = n - 1, {select(2, ...)}
if type(seps[n])=='table' then
if buffHTML and rawget(seps[n], buffHTML) then
return ...
end
setmetatable(seps, {
__index = setmetatable(seps[n], {
__index = function(t)
return rawget(t, 1)
end
})
})[n] = nil
end
return ..., seps
end
local _inHTML
do
local lastBuffer, lastHTML
local function init(...) -- init replaced and new version called on return
local create, mwFunc = mw.html.create
do
local mwHTMLmeta = getmetatable(create())
buffHTML, mwFunc, _inHTML = setmetatable(mw.clone(mwHTMLmeta), getmetatable(MB)), mwHTMLmeta.__index -- buffHTML declared near top of module; remove _inHTML from outer scope
function init(nodes, ...)
local name, args, tag = select(... and type(...) == 'table' and 1 or 2, nil, ...)
tag = create(Valid(name), args)
if nodes then
table.insert(nodes, tag.parent and tag or rawset(tag, 'parent', parent[nodes]))
end
if args then
local a, b = args.selfClosing, args.parent
args.selfClosing, args.parent = nil
if next(args) then
Element._add(parent(tag.nodes, tag), args)
end
args.selfClosing, args.parent = a, b -- in case args is reused
end
return tag
end
for k, v in next, {[mw] = mwHTMLmeta,
__call = function(h, v)
return MBmix(spec[h.nodes] and h.nodes or spec(setmetatable(parent(h.nodes, h), MB), Element), v)
end,
__concat = false, -- false means take from MB
__eq = false
} do
buffHTML[k] = v or MB[k]
end
end
local nonSelf, BHi = {tag = true,done = true,allDone = true}, buffHTML.__index
do
local g
g = {__index = function(t, i)
if gfuncs and gfuncs[i] then
g.__index, gfuncs = gfuncs
return g.__index[i]
end
end}
setmetatable(nonSelf, g)
setmetatable(BHi, g)
end
for k in next, nonSelf do
-- any HTML objects returned by these funcs will be granted Module:Buffer enhancements
local func = mwFunc[k]
BHi[k] = function(t, ...)
local HTML = func(t, ...)
return parent[HTML] and HTML or setmetatable(parent(HTML, t), buffHTML)
end
end
do
local function joinNode(HTML, sep)
local nodes, join = HTML.nodes
if noCache and rawkey[sep] or Valid(sep) then
join, HTML.nodes = tostring(rawset(HTML, 'nodes', {MB.__call(nodes, sep)})), nodes
end
return join or tostring(HTML)
end
for k, v in next, {
getParent = function(HTML, ...)
lastHTML = HTML
return MBi.getParent(HTML:allDone(), ...)
end, -- return to Buffer that created the HTML tree
getBuffer = function(HTML, ...)
lastHTML = HTML
return isMBfunc(lastBuffer, ...)
end, -- return to last used
killParent = function(HTML, ...)
MBi.killParent(HTML:allDone(), ...)
return HTML
end,
_out = function(HTML, ...)
if ... == 0 then
MBi._out(HTML.nodes, ...)
return HTML
end
lastHTML, HTML = HTML, HTML:allDone()
local n, ops, seps = select('#', ...)
if n > 1 then
local ops, seps = MBselect(n, ...)
return parent[HTML]:_in(joinNode(HTML, rawget(seps, 0))):_out(ops, rawset(seps, buffHTML, true))
end
return parent[HTML]:_(joinNode(HTML, ...))
end,
_str = function(HTML, ...)
-- does not set lastHTML
if ... == 0 then
return joinNode(HTML, select(2, ...))
end -- passing 0 strings without calling allDone()
local HTML, n = HTML:allDone(), select('#', ...)
if n > 1 then
local ops, seps = MBselect(n, ...)
return parent[HTML]:_in(joinNode(HTML, rawget(seps, 1))):_str(ops, rawset(seps, buffHTML, true))
end
return joinNode(HTML, ...)
end,
_parent = function(HTML, ...)
table.insert(HTML.nodes, parent[HTML:allDone()]:_str(...))
return HTML
end
} do
BHi[k] = v
end
end
do
local htmlArg, skip, outFuncs = {parent = true,selfClosing = true,tagName = true}, {}
do
local out local function func(nodes, ...)
return out(parent[nodes], ...)
end
outFuncs = setmetatable({
tag = function(nodes, ...)
return parent(setmetatable(init(nodes, ...), buffHTML), parent[nodes])
end,
done = function(b, ops)
b = parent[b]
while b.parent and ops ~= 0 do
b, ops = b.parent, ops and ops - 1 or 0
end
return b
end
}, {__index = function(nodes, i)
if rawget(BHi, i) then
out = BHi[i]
return func
end -- rawget to exclude globals
end})
end
Element = {
_add = function(nodes, t)
for k, v in MBpairs(t), t, skip[t] do
(v ~= true and MBmix or noOp)(nodes, v)
end
local HTML = parent[nodes] for k, v in MBpairs(t, false) do
if htmlArg[k] then
HTML[k] = v
elseif v and v ~= true then
if nonSelf[k] then
if k == 'tag' then
if type(v) == 'table' then
skip[v], k = 1, rawset(create(Valid(v[1])), 'parent', HTML)
Element._add(spec(parent(k.nodes, k, table.insert(nodes, k)), Element), v)
if k.selfClosing then
k.nodes = nil else spec[k.nodes], parent[k.nodes] = nil
end -- free memory/reduce clutter; parent ref will auto-unset when k.nodes is nil
if not k.tagName then
k.styles, k.attributes = nil
end
else table.insert(nodes, create(v))
end
elseif mwFunc[k] then
if k == 'done' and tonumber(v) ~= v and v[1] and tonumber(v[1]) == v[1] then
skip[v] = 1
end
MBmix(outFuncs[k](nodes, skip[v] and v[1]).nodes, v)
elseif v[1] or v[2] then
k = MBi[k](nodes, unpack(v, 1, rawset(skip, v, k == '_B' and 1 or 2)[v]))
Element._add(getmetatable(k) and rawget(k, 'nodes') or k, v) -- if k is not a table, then v should not contain any extra keys or this may error.
else MBi[k](nodes, v)
end -- k probably == '_G' or '_R'
elseif mwFunc[k] then
if type(v) ~= 'table' or rawget(v, 'nodes') then
mwFunc[k](HTML, v)
else
local css = k == 'css'
for x, y in MBpairs(v, true) do
(y and y ~= true and mwFunc[k] or noOp)(HTML, css and x:gsub('_', '-') or x, y)
end -- iterate non-numbers first
for _, y in MBpairs(v, nil) do
(y and y ~= true and mwFunc[k] or noOp)(HTML, y)
end -- don't bother with gsub since text must be quoted anyhow
end
elseif rawget(Element, k) or rawget(MBi, k) then
if tonumber(v) == v or v[1] == nil or getmetatable(v) then
(Element[k] or MBi[k])(nodes, v) -- v is probably string-able object, or a table to be handled by :_all
else (Element[k] or MBi[k])(nodes, unpack(v, 1, table.maxn(v)))
end -- v is definitely a table
else mwFunc.css(HTML, k:gsub('_', '-', 1), tostring(v))
end -- oddly enough, :_add clocked its fastest runtime after adding auto-gsub as a feature
skip[v] = nil
end
end
return nodes
end
}
local tempMeta = {mode = 'v', copy = {styles = true,attributes = true}}
function tempMeta.__index(t, i)
return tempMeta.copy[i] and rawset(t, i, MBi._cc(false, 0, t.orig[i]))[i] or t.orig[i]
end
rawkey[setmetatable(Element, {__index = outFuncs, __concat = function(Element, v)
return setmetatable({nodes = spec({}, Element),orig = parent[v]}, tempMeta)
end})] = math.huge
end
function MBi:getHTML(...)
lastBuffer = self
if ... then
if select('#', ...) == 1 then
return not rawkey[s] and tostring(...):match'^_' and BHi[...] and BHi[...](lastHTML) or lastHTML(...)
else
return assert(BHi[...], ('" %s " does not match any mw.html or Buffer-mw.html function'):format(tostring(...)))(lastHTML, select(2, ...))
end
end
return lastHTML
end
function MBi:_html(...)
return MBi._(self, lastHTML, select(spec[self] == Element and select('#', ...) == 0 and 1 or 2, true, ...))
end
return init(...)
end
function _inHTML(self, ...)
local HTML = init(nil, ...)
if HTML.selfClosing and spec[self] == Element then
self.last_concat = table.insert(self, HTML)
return self
end
lastBuffer, lastHTML = self, setmetatable(parent(HTML, self), buffHTML) -- set after 'args' table processed by :_add
return HTML
end
end
local _var, unbuild do
local prev, rebuild
local function init(...) -- init replaced before return
local function pick(b, v)
return b and table.insert(b, v) or v
end
local function c(a, num)
return rawset(a.a or a, 0, a[0] and a[0] + a.c or num and a[1] or a[1]:byte())[0]
end
local same, build, alt = {__tostring = function(a, b)
return a.a[0] and pick(b, a.a.string and string.char(a.a[0]) or a.a.table and a.a[1][a.a[0]] or a.a[0])
end}, {
__index = {c = 1},
__tostring = function(t)
return t:_build()
end,
table = function(a, b)
local i = next(a[1], a[0]) or a[0] == #a[1] and next(a[1])
return pick(b, rawset(a.a or a, 0, i)[1][i])
end, -- change rate (a.c) ignored since users control the table's contents
number = function(a, b)
return pick(b, c(a, true))
end,
string = function(a, b)
return pick(b, string.char(c(a)))
end
}, {__index = function(a, i)
return a.a[i]
end, __tostring = function(a, b)
return (rawget(a, 0) and a[0] == tostring(a[0]) and rawset(a, 0, a[0]:byte()) or a).a._build(a, b) end}
local function shift(t, c)
t[0] = t[0] and t[0] + c or t:_build() and t[0] - t.c + c
if t.table then
t[0] = (t[0] - 1) % #t[1] + 1
end
end
function rebuild(...)
local v, c = ...
if v or select('#', ...) == 0 then
if v and not c then
return prev
end
local meta, c = select(v and 1 or 3, alt, c, same, 0)
return setmetatable({a = prev, _build = meta.__tostring, c = c}, meta)
elseif v == nil then
-- no-op
elseif c then
shift(prev, c) -- v == false
else prev:_build()
end
end
init, noCache = function(v, c)
prev = setmetatable({v, c = c, _build = build[type(v)] or v, [type(v)] = true, alt = {}}, build)
return prev
end, true
return init(...)
end
function unbuild(sep)
for k, v in MBpairs(sep, nil) do
k = getmetatable(v) if k and (k == build or k == alt) then
shift(v.a or v, -v.c)
end
end
end
function _var(self, ...)
local obj if ... and ... ~= true then
obj = init(...)
elseif prev then
if ... ~= false then
obj = rebuild(...)
else rebuild(...)
end
end
return obj and MBi._(self, obj, nil, true) or self
end
end
local lib; MBi = setmetatable({stream = _stream,
_inHTML = _inHTML,
_var = _var,
_ = function(self, v, ...)
local at, raw = select(select('#', ...) == 1 and ... == true and 1 or 2, nil, ...)
if raw then
rawkey[self] = math.huge else v = Valid(v)
end
if v or raw then
if at or rawkey[self] then
raw = #self
end -- if length increases by more than one after table.insert, then set rawkey[self] = math.huge; rawkey[self] may be equal to a previous 'at'
at, self.last_concat = at and (tonumber(at) ~= at and raw + at or at)
table.insert(self, select(at and 1 or 2, at, v))
if at and at < 0 or raw and #self - raw > 1 then
rawkey[self] = math.huge elseif at and #self == raw then rawkey[self] = rawkey[self] and math.max(rawkey[self], at) or at
end
end -- above line looks bizarre because one table.insert op may make length jump from 0 to 8: local wtf = {[2] = 2,[4] = 4,[8] = 8}mw.log(#wtf,table.insert(wtf,1),#wtf)
return self
end,
_nil = function(self, at, ...)
if ... ~= true and ... ~= false then
-- faster than type(...) ~= 'boolean'
if not at or at == '0' then
self[#self] = ... if ... then
rawkey[self] = math.huge
end
else
local n, v = tonumber(at), ...
if n ~= at then
if n then
n = #self + at
elseif at ~= true and select('#', ...) == 0 then
v, n = at, #self
end
end
if n then
if v == nil and n > 0 then
table.remove(self, n)
else self[math.floor(n)], rawkey[self] = v, math.huge
end -- floor position for consistency with Table library
end
end
self.last_concat = nil
end
return self
end,
_all = function(self, t, valKey)
for k, v in MBpairs(t) do
MBmix(self, v, valKey)
end
for k, v in valKey and MBpairs(t, false) or noOp, t do
if tonumber(v) then
MBi._(self, k, v) -- self not always a buffer
elseif rawget(MBi, k) and v and v ~= true then
if v[1] == nil or getmetatable(v) then
MBi[k](self, v)
else MBi[k](self, unpack(v, 1, table.maxn(v)))
end
end
end
return self
end,
_str = function(t, ...)
local n = select('#', ...)
if n > 1 then
local k, ops, seps, r = 2, MBselect(n, ...)
r = MB(t(seps[1]))
while parent[t] and ops > 1 and r:_(parent[t](seps[k]), 1) do
t, k, ops = parent[t], k + 1, ops - 1
end
return table.concat(r, seps[k] or nil)
end
return MB.__call(t, ...)
end,
_in = function (self, ...)
return parent(MB(...), self)
end,
_out = function(t, ...)
if ... == 0 then
return parent(t, parent[t], MBi._cc(t, t, MB.__call(t, (select(2, ...))), getmetatable(t)))
end -- love how :_cc needed nothing new to implement this *self pat on back*
local n = select('#', ...)
if n > 1 then
local k, ops, seps = 1, MBselect(n, ...)
while parent[t] and ops > 0 do
t, k, ops = parent[t]:_(t(seps[k])), k + 1, ops - 1
end
elseif parent[t] then
return parent[t]:_(t(...))
end
return t
end,
_cc = function(self, clear, copy, meta)
if clear then
if rawequal(clear, copy) then
return self, spec[MBi._cc] and setmetatable(spec[MBi._cc], MB) -- rawequal to avoid re-string via __eq in case both are different Buffer objects
elseif copy == true then
copy = self
end
if clear ~= 0 then
assert(type(clear) == 'table', debug.traceback('Buffer:_cc can only "clear" tables. Did you forget to call with a colon?', 2)) -- errors can be hard to trace without this
for k in self and next or noOp, clear do
rawset(clear, k, nil)
end
else
return MBi._cc(false, {unpack(copy)}, copy)
end -- copy length w/o empty strings; recursion to avoid self = false causing garbage collection (non-weak child may exist)
if self == false or copy and type(copy) == 'table' then
-- self == false means copy is a table (saves a type op for recursive calls)
meta = meta or getmetatable(copy)
if self and #copy > 1 then
-- preserves length with empty strings; developed from studying http://www.lua.org/source/5.1/ltable.c.html
local n, null, i, e = #copy, {}, math.ldexp(2, select(2, math.frexp(#copy)) - 2)
e, spec[MBi._cc], parent[null] = i - 1, null, clear
for k = 1, e do
table.insert(clear, false)
end
while i <= n do
table.insert(clear, i, ) i, null[i] = i + math.ldexp(2, select(2, math.frexp(n - i)) - 2),
end
for k = 1, e do
rawset(clear, k, nil)
end
end
for k, v in next, copy do
rawset(clear, k, type(v) == 'table' and MBi._cc(false, 0, v) or v)
end
elseif copy then
rawset(clear, 1, (Valid(copy)))
end
rawkey[setmetatable(clear, meta)], parent[clear] = rawkey[copy], parent[copy]
end
return self and rawset(self, 'last_concat', nil) or clear
end,
_parent = function(self, ...)
return parent[self] and MBi._(self, parent[self]:_str(...)) or self
end,
getParent = function(self, ...)
return isMBfunc(parent[self] or parent[parent(self, setmetatable({}, MB))], ...)
end,
killParent = function(self, ...)
return parent[self] and isMBfunc(parent[self], ...) and parent(self) or self
end,
_build = function(self, t)
table.insert(t, self())
end, -- for compatibility with mw.html:node()
last_concat = false -- prevent library check
}, {__index = function(t, i)
-- import string, mw.text, and mw.ustring libraries on an as-needed basis
local func = string[i] or mw.text[i] or mw.ustring[i] or type(i) == 'string' and mw.ustring[i:match'^u(.+)'] if func then
lib = lib or function (s, f, ...)
if parent[s] and next(s) == nil then
return s:_((f(tostring(parent[Element and (spec[s] == Element and s:allDone() or spec[parent[s]] == Element and parent[s]) or s]), ...)))
end
return f(tostring(s), ...) -- not using ternary/logical operators here to allow multiple return values
end
return rawset(t, i, i:match'^u?gsub' and function(self, p, r, ...)return lib(self, func, p, r or '', ...)end -- Why are ugsub/gsub special? because empty strings are against my religion!
or function(self, ...)return lib(self, func, ...)end)[i]
end
end})
end
function MBmix(t, v, ...)
return v and ((type(v) ~= 'table' or getmetatable(v)) and MBi._(t, v) or (select('#', ...) == 0 and spec[t] and spec[t]._add or MBi._all)(t, v, ...)) or t
end -- :_all always passes two args
local _G, new_G = _G -- localize _G for console testing (console _G ~= module _G)
return setmetatable({__index = function(t, i)
return spec[t] and spec[t][i] or MBi[i]
end,
__call = function(t, ...)
local rawsep, sep, i, j, raw = noCache and rawkey[...] and ..., ...
if i or j or rawsep or Valid(sep) then
raw, sep, i, j = rawkey[spec[t]] or rawkey[t], rawsep or Valid(sep), i and (i ~= tonumber(i) and i + #t or i), j and (j ~= tonumber(j) and j + #t or j)
if rawsep or raw and (raw >= (j or #t) or i < 1) then
raw, i, j = {}, i and math.floor(i), j and math.floor(j) -- floor for consistency with table.concat(t, sep, i, j), which ignores decimals
raw.lc, t.last_concat = t.last_concat -- temporarily unset last_concat to prevent disqualification from mapless iteration
for k, v in MBpairs(t) do
if raw[1] or not i or k >= i then
if j and k > j then break
end
if raw.s then
raw.s = table.insert(raw, tostring(sep))
end -- if sep contains v and v is a Buffer-variable, sep must be strung before v
k = Valid(v) if k then
raw.s = rawsep or sep and raw[1] and table.insert(raw, sep)
table.insert(raw, k)
end
end
end
if rawsep and not raw.s then
raw[#raw] = unbuild(sep)
end -- unbuild rawsep if final index in t was invalid
t.last_concat = raw.lc
return table.concat(raw)
end
return table.concat(t, sep, i and math.max(i, 1), j and math.min(j, #t))
end
return MB.__tostring(t)
end,
__tostring = function(t)
if t.last_concat then
return t.last_concat
end
local r = rawkey[spec[t]] or rawkey[t]
r = table.concat(r and r >= #t and MBi._all({}, t) or t)
return (noCache or rawset(t, 'last_concat', r)) and r
end,
__concat = function(a, b)
if buffHTML then
for k = 1, 2 do
local v = select(k, a, b) -- faster than for k, v in pairs{a, b} do
if v and spec[v] and spec[v] == Element then
if parent[v].selfClosing then
if rawequal(a, b) then
return (not noCache or parent[v].tagName) and v:_str(0):rep(2) or v:_str(0)..v:_str(0)
end -- rawequal avoids premature tostring of Buffer:_var objects;
b, a = select(k, b, parent[v], a)
else local temp = Element .. v --helper method; returns a mirror of parent[v]
MBmix(MBmix(parent(temp.nodes, temp), a), k == 1 and spec[b] == Element and parent[b] or b)
return buffHTML.__tostring(setmetatable(temp, {__index = parent[v], __mode = 'v'})) -- switch from tempMeta to avoid MBi._cc op of styles/attributes
end
end
end
end
return table.concat(MBmix(MBmix({}, a), b))
end,
__pairs = MBpairs,
__ipairs = MBpairs,
__eq = function(a, b)
return tostring(a) == tostring(b)
end -- avoid a == b in this module; use rawequal(a,b) when they may be different Buffers (premature tostring waste ops and is bad for Buffer:_var)
}, {__tostring = function()return''end,
__call = function(self, ...)
MB = MB or self
if new_G then
if ... and _G and ... == _G then new_G = ...
end
elseif ... and (... == _G or type(...) == 'table' and (...)._G == ...) then
local Nil, mG = {}, (...):getmetatable() or (...):setmetatable{}:getmetatable()
new_G, _G, gfuncs = ..., ..., { -- gfuncs stored for Buffer:_inHTML; new_G is a is a Module:Buffer local declared just before the final return statement.
_G = function(self, i, ...)
local X, save = rawget(new_G, i), select('#', ...) == 0 and self or ...
if i and i ~= true and not (X and save and rawequal(X, save)) and rawset(new_G, i, save) and (X ~= nil or save == nil and new_G[i] ~= nil) then
-- rawequal in case X is another buffer
local mG = getmetatable(new_G) or {__call = mG.__call}
if mG.__index then
pcall(rawset, mG.__index, i, X)
else mG.__index = setmetatable(new_G, mG) and {[i] = X}
end
end
return self, ... -- avoiding __eq with rawequal(self,save) is overkill since buffers can self-save without being passed as save
end,
_R = function(self, i, v, m)
if i ~= 'new_G' then
if i and i ~= true then rawset(new_G, i , v)
end
elseif not v or v == true or v._G ~= _G then
new_G = setmetatable(v ~= true and v or {}, {__call = mG.__call, __index = v ~= true and m ~= true and (m or new_G) or nil})
else new_G, (not m and (m ~= nil or v == new_G) and Nil or getmetatable(v)).__index = v, m ~= true and (m or new_G) or nil
end -- setting Nil.__index is noOp
return self
end,
_2 = function(self, ...)
if new_G[...] ~= nil then
return new_G[...]
end -- higher priority so Buffer:_G('new_G', ...) can prevent an overwrite
if ... == 'new_G' then
return rawset((select('#', ...) ~= 1 and MBi._R(new_G, ...) or new_G), '_G', _G)
end
return select(select('#', ...) == 1 and 1 or 2, self:_G(...)) --return only one value; 'return select(2, self:_G(...)) or self' doesn't work for returning nil
end,
_B = function(self, v)
return v or v == nil and Nil
end
} for k, v in next, gfuncs do
MBi[k] = v
end
setmetatable(Nil,{__concat = MB.__concat,__newindex = noOp,__call = noOp,__tostring = noOp,__metatable = MB,__index = setmetatable({_B = MBi._B,_ = function()return Nil
end,last_concat = ''},
{__index = function(t,i)return (MBi[i] or i and not tonumber(i)) and t._ or nil
end})})
function mG.__call(G, k, ...)
return (k._G or G.type(k) == 'table') and (G.select('#', ...) ~= 1 and G.rawset(k, ...) or G:rawset(..., k) and k) or G:rawset(k, (...)) and ...
end
end
local new = setmetatable({}, self)
if ... and (...) == new_G then
return select(2, ...) and MBmix(new:_G((select(2, ...))), select(3, ...)) or new
end
return ... and MBi._(new, ...) or new
end,
__index = function(t, i)
MB = MB or t
return MBi[i] and function(...)
return MBi[i](setmetatable({}, t), select(... == t and 2 or 1,...))
end
end
})