Mô đun:Buffer

--
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
--
local function Valid(v)--type validation
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)
if str~=v and str=='table' then return rawget(v, 1) and table.concat(v) end--tostring(string-type) returns same ref; same refs compare faster than type()
if str~= then return str end--numbers are coerced to string per table.concat op; appending in string form saves ops on repeat concat
end
end
local noOp, MBpairs = 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 end--slightly faster to do this than to use select()
function pIter(t, k) k = (iMap[t] or MBpairs(t, true) and iMap[t])[not k and 1 or vMap[t][k]] return k, t[k] end--don't use rawget; accepting unmapped tables does not measurably affect performance.
function pOther(t, k) k = (oMap[t] or MBpairs(t, true) and oMap[t])[nil==k and 1 or vMap[t][k]] return k, t[k] end--comparison to nil because false is a valid key
function pFast(t, k) k = not k and 1 or k 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 definately 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 " không phù hợp với bất kỳ mw.html hoặc chức năng Buffer-mw.html'):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 vnil 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 (kbuild or kalt) 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 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 chỉ có thể bảng "clear". Bạn đã quên gọi với một dấu hai chấm?', 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 selffalse 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=(j or t) or i =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), k1 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 ab 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()returnend,
__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
})