Module:ArrayList

 localp={}

 -- Helper function to trim whitespace
 localfunctiontrim(s)
 returns:match("^%s*(.-)%s*$")
 end

 -- Escape special characters in the delimiter for pattern matching
 localfunctionescapePattern(str)
 returnstr:gsub("([%^%$%(%)%%%.%[%]%*%+%?%-])","%%%1")
 end

 -- Main function to call other functions dynamically
 functionp.main(frame)
 localfunc=frame.args[1]
 ifp[func]then
 returnp[func](frame)
 else
 return"void:notfound "..tostring(func)
 end
 end

 -- Count occurrences of delimiter in a string
 functionp.count(frame)
 localstr=frame.args[2]or""
 localdelimiter=frame.args[3]or","
 localnostrip=frame.args["nostrip"]

 delimiter=escapePattern(delimiter)

 -- If nostrip is not set to "true", strip leading/trailing delimiters
 ifnostrip~="true"then
 -- Remove leading and trailing delimiters (along with any surrounding whitespace)
 str=str:gsub("^%s*"..delimiter.."%s*",""):gsub("%s*"..delimiter.."%s*$","")

 -- Normalize internal consecutive delimiters to a single delimiter (replace ",," with ",")
 str=str:gsub("%s*"..delimiter.."%s*"..delimiter.."%s*",delimiter)
 end

 localcount=select(2,str:gsub(delimiter,""))
 returncount+1
 end

 -- Get the Nth item in a delimited string, supporting negative indices
 functionp.get(frame)
 localstr=frame.args[2]or""
 localdelimiter=frame.args[3]or","
 localindex=frame.args[4]
 delimiter=escapePattern(delimiter)
 str=str:gsub("^%s*"..delimiter.."%s*(.-)%s*"..delimiter.."$","%1")
 localitems={}
 foriteminstring.gmatch(str,"([^"..delimiter.."]+)")do
 table.insert(items,trim(item))
 end
 ifindex=="last"then
 index=#items
 elseifindexandtonumber(index)then
 index=tonumber(index)
 ifindex<0then
 index=#items+index+1
 end
 else
 return"void:invalid"
 end
 returnitems[index]or"void:outrange"
 end

 -- Find the position of the Nth occurrence of a matching item in a delimited string
 functionp.pos(frame)
 localstr=frame.args[2]or""
 localdelimiter=frame.args[3]or","
 localitem=frame.args[4]or""
 localoccurrence=tonumber(frame.args[5])
 delimiter=escapePattern(delimiter)
 str=str:gsub("^%s*"..delimiter.."%s*(.-)%s*"..delimiter.."$","%1")
 localpositions={}
 localindex=1
 forsubiteminstring.gmatch(str,"([^"..delimiter.."]+)")do
 subitem=trim(subitem)
 ifsubitem==itemthen
 table.insert(positions,index)
 end
 index=index+1
 end
 ifnotoccurrencethen
 return#positions>0andtable.concat(positions,",")or"void:nomatch"
 else
 returnpositions[occurrence]or-1
 end
 end

 -- Perform mathematical operations on numeric array items
 functionp.math(frame)
 localstr=frame.args[2]or""
 localdelimiter=frame.args[3]or","
 localoperation=frame.args[4]
 delimiter=escapePattern(delimiter)
 str=str:gsub("^%s*"..delimiter.."%s*(.-)%s*"..delimiter.."$","%1")
 localitems={}
 foriteminstring.gmatch(str,"([^"..delimiter.."]+)")do
 localnumber=tonumber(trim(item))
 ifnumberthen
 table.insert(items,number)
 else
 return"void:isalpha"
 end
 end
 if#items==0then
 return"void:nonumeric"
 elseifoperation=="sum"then
 localtotal=0
 for_,numinipairs(items)do
 total=total+num
 end
 returntotal
 elseifoperation=="min"oroperation=="max"then
 localextreme=items[1]
 localcomparison=operation=="min"andfunction(a,b)returna<bendorfunction(a,b)returna>bend
 for_,numinipairs(items)do
 ifcomparison(num,extreme)then
 extreme=num
 end
 end
 returnextreme
 else
 return"void:unsupported"
 end
 end

 -- Sorts array with options for reverse ("r") and alpha-first ("a").
 functionp.sort(frame)
 localstr=frame.args[2]or""
 localdelimiter=frame.args[3]or","
 localparams=frame.args[4]or""
 localdelim_pat=escapePattern(delimiter)

 -- Determine sort options (check if params a or r expressed)
 localreverse=params:find("r")andtrueorfalse
 localalpha_priority=params:find("a")andtrueorfalse

 localitems={}
 localorig_index=1
 -- Split string using delimiter.
 foriteminstring.gmatch(str,"([^"..delim_pat.."]+)")do
 item=item:match("^%s*(.-)%s*$")-- trim whitespace
 localnum=tonumber(item)
 localisnum=(num~=nil)
 localisalpha=(notisnumanditem:match("^[A-Za-z]+$"))andtrueorfalse
 localgroup
 ifalpha_prioritythen
 ifisalphathen
 group=1
 elseifisnumthen
 group=2
 else
 group=3
 end
 else
 ifisnumthen
 group=1
 elseifisalphathen
 group=2
 else
 group=3
 end
 end

 table.insert(items,{
 raw=item,
 num=num,
 isnum=isnum,
 isalpha=isalpha,
 group=group,
 orig=orig_index-- remember original order for special items
 })
 orig_index=orig_index+1
 end

 table.sort(items,function(a,b)
 -- compare groups
 ifa.group~=b.groupthen
 returna.group<b.group
 end

 -- if both items in same group, decide
 -- comparison based on alpha_priority flag
 ifalpha_prioritythen
 -- if letters come first, group 1 = letters
 ifa.group==1then-- Both are alphabetic.
 returna.raw:lower()<b.raw:lower()
 elseifa.group==2then-- Both are numeric.
 returna.num<b.num
 else-- Group 3: special items.
 returna.orig<b.orig
 end
 else
 -- if numbers first, group 1 = numbers
 ifa.group==1then-- Both are numeric.
 returna.num<b.num
 elseifa.group==2then-- Both are alphabetic.
 returna.raw:lower()<b.raw:lower()
 else-- Group 3: special items.
 returna.orig<b.orig
 end
 end
 end)

 -- Reverse order if requested
 ifreversethen
 fori=1,math.floor(#items/2)do
 items[i],items[#items-i+1]=items[#items-i+1],items[i]
 end
 end

 -- Build output string
 localoutput={}
 for_,vinipairs(items)do
 table.insert(output,v.raw)
 end
 returntable.concat(output,delimiter)
 end

 returnp