Module:Sandbox/AnataBakka2

Documentation for this module may be created at Module:Sandbox/AnataBakka2/doc

-- <pre>
local p     = {}
local lib   = require('Module:Feature')
local iter = 50000

function p.test(frame)
    local args; if frame.args == nil then args = lib.arguments(frame) else args = lib.arguments(frame.args) end
    return expr(args[1])
end

function expr(val)
    if string.find(val, "[0-9]") == nil then
        return val
    end
    val = string.gsub(val," ","")
    
    local symbol={
    ["^"]=1,
    ["/"]=2,
    ["*"]=3,
    ["+"]=4,
    ["-"]=5,
    [")"]=6,
    ["("]=7
    }
    
    local getmath = {
    ["^"] = function (a,b) return a^b end,
    ["/"] = function (a,b) return a/b end,
    ["*"] = function (a,b) return a*b end,
    ["+"] = function (a,b) return a+b end,
    ["-"] = function (a,b) return a-b end
    }
    
    local symbolstack = {}
    local numberstack = {}
    
    local term=""
    for i=1,#val,1 do
    	term = term .. string.sub(val,i,i)
    	if symbol[term] == nil or ((term == "-" or term == "+") and (symbol[string.sub(val,i-1,i-1)] ~= nil or i-1 == 0) and string.sub(val,i-1,i-1) ~= ")")  then
    		if symbol[string.sub(val,i+1,i+1)] ~= nil or i == #val then
    			table.insert(numberstack,term)
    			term=""
    		end
    	else
    		if symbolstack[#symbolstack] ~= nil and symbol[symbolstack[#symbolstack]] < symbol[term] and term ~= "(" and term ~= ")" then
    			table.insert(numberstack,symbolstack[#symbolstack])
    			symbolstack[#symbolstack] = term
    		else
    			table.insert(symbolstack,term)
    		end
    		if term == ")" then
    			closed = true
    		end
    		term=""
    	end
    	if closed == true then
    		table.remove(symbolstack,#symbolstack)
    		while symbolstack[#symbolstack] ~= "(" do
    			table.insert(numberstack,symbolstack[#symbolstack])
    			table.remove(symbolstack,#symbolstack)
    		end
    		closed = false
    		table.remove(symbolstack,#symbolstack)
    	end
    end
    
    for i = #symbolstack, 1, -1 do
    	table.insert(numberstack,symbolstack[i])
    end
    
    local tempstack = {}
    
    while numberstack[#numberstack] ~= nil do
    	if symbol[numberstack[1]] == nil then
    		table.insert(tempstack,numberstack[1])
    	else
    		table.insert(tempstack,getmath[numberstack[1]](tempstack[#tempstack-1], tempstack[#tempstack]))
    		table.remove(tempstack,#tempstack-1)
    		table.remove(tempstack,#tempstack-1)
    	end
    	table.remove(numberstack,1)
    end
    
    if tempstack[1] * 2 ~= nil then
        return tempstack[1] 
    end
end

function last(val, sign)
    return string.sub(val, 1 - (string.find(string.reverse(val), string.reverse(sign), 1, true) or 0))
end

return p
-- </pre>
-- [[Category:Lua sandbox]]