Module:Unsubst

 localcheckType=require('libraryUtil').checkType

 localp={}

 localBODY_PARAM='$B'

 localspecialParams={
 ['$params']='parameter list',
 ['$aliases']='parameter aliases',
 ['$flags']='flags',
 ['$B']='template content',
 ['$template-name']='template invocation name override',
 }

 functionp.main(frame,body)
 -- If we are substing, this function returns a template invocation, and if
 -- not, it returns the template body. The template body can be specified in
 -- the body parameter, or in the template parameter defined in the
 -- BODY_PARAM variable. This function can be called from Lua or from
 -- #invoke.

 -- Return the template body if we aren't substing.
 ifnotmw.isSubsting()then
 ifbody~=nilthen
 returnbody
 elseifframe.args[BODY_PARAM]~=nilthen
 returnframe.args[BODY_PARAM]
 else
 error(string.format(
 "no template content specified (use parameter '%s' from #invoke)",
 BODY_PARAM
 ),2)
 end
 end

 -- Sanity check for the frame object.
 iftype(frame)~='table'
 ortype(frame.getParent)~='function'
 ornotframe:getParent()
 then
 error(
 "argument #1 to 'main' must be a frame object with a parent "..
 "frame available",
 2
 )
 end

 -- Find the invocation name.
 localmTemplateInvocation=require('Module:Template invocation')
 localname

 ifframe.args['$template-name']and''~=frame.args['$template-name']then
 name=frame.args['$template-name']-- override whatever the template name is with this name
 else
 name=mTemplateInvocation.name(frame:getParent():getTitle())
 end

 -- Combine passed args with passed defaults
 localargs={}
 ifstring.find(','..(frame.args['$flags']or'')..',',',%s*override%s*,')then
 fork,vinpairs(frame:getParent().args)do
 args[k]=v
 end
 fork,vinpairs(frame.args)do
 ifnotspecialParams[k]then
 ifv=='__DATE__'then
 v=mw.getContentLanguage():formatDate('F Y')
 end
 args[k]=v
 end
 end
 else
 fork,vinpairs(frame.args)do
 ifnotspecialParams[k]then
 ifv=='__DATE__'then
 v=mw.getContentLanguage():formatDate('F Y')
 end
 args[k]=v
 end
 end
 fork,vinpairs(frame:getParent().args)do
 args[k]=v
 end
 end

 -- Trim parameters, if not specified otherwise
 ifnotstring.find(','..(frame.args['$flags']or'')..',',',%s*keep%-whitespace%s*,')then
 fork,vinpairs(args)doargs[k]=mw.ustring.match(v,'^%s*(.*)%s*$')or''end
 end

 -- Pull information from parameter aliases
 localaliases={}
 ifframe.args['$aliases']then
 locallist=mw.text.split(frame.args['$aliases'],'%s*,%s*')
 fork,vinipairs(list)do
 localtmp=mw.text.split(v,'%s*>%s*')
 aliases[tonumber(mw.ustring.match(tmp[1],'^[1-9][0-9]*$'))ortmp[1]]=((tonumber(mw.ustring.match(tmp[2],'^[1-9][0-9]*$')))ortmp[2])
 end
 end
 fork,vinpairs(aliases)do
 ifargs[k]and(notargs[v]orargs[v]=='')then
 args[v]=args[k]
 end
 args[k]=nil
 end

 -- Remove empty parameters, if specified
 ifstring.find(','..(frame.args['$flags']or'')..',',',%s*remove%-empty%s*,')then
 localtmp=0
 fork,vinipairs(args)do
 ifv~=''or(args[k+1]andargs[k+1]~='')or(args[k+2]andargs[k+2]~='')then
 tmp=k
 else
 break
 end
 end
 fork,vinpairs(args)do
 ifv==''then
 ifnot(type(k)=='number'andk<tmp)thenargs[k]=nilend
 end
 end
 end

 -- Order parameters
 ifframe.args['$params']then
 localparams,tmp=mw.text.split(frame.args['$params'],'%s*,%s*'),{}
 fork,vinipairs(params)do
 v=tonumber(mw.ustring.match(v,'^[1-9][0-9]*$'))orv
 ifargs[v]thentmp[v],args[v]=args[v],nilend
 end
 fork,vinpairs(args)dotmp[k],args[k]=args[k],nilend
 args=tmp
 end

 returnmTemplateInvocation.invocation(name,args)
 end

 p['']=p.main-- For backwards compatibility

 returnp