函数

计算长度

function table_leng(t)
  local leng=0
  for k, v in pairs(t) do
    leng=leng+1
  end
  return leng;
end

function trim(s)
  return (string.gsub(s, "^%s*(.-)%s*$", "%1")) 
end
打印表
function print_r ( t )  
    local print_r_cache={}
    local function sub_print_r(t,indent)
        if (print_r_cache[tostring(t)]) then
            print(indent.."*"..tostring(t))
        else
            print_r_cache[tostring(t)]=true
            if (type(t)=="table") then
                for pos,val in pairs(t) do
                    if (type(val)=="table") then
                        print(indent.."["..pos.."] => "..tostring(t).." {")
                        sub_print_r(val,indent..string.rep(" ",string.len(pos)+8))
                        print(indent..string.rep(" ",string.len(pos)+6).."}")
                    elseif (type(val)=="string") then
                        print(indent.."["..pos..'] => "'..val..'"')
                    else
                        print(indent.."["..pos.."] => "..tostring(val))
                    end
                end
            else
                print(indent..tostring(t))
            end
        end
    end
    if (type(t)=="table") then
        print(tostring(t).." {")
        sub_print_r(t,"  ")
        print("}")
    else
        sub_print_r(t,"  ")
    end
    print()
end

去重复
function table_unique(t) 
    local check = {};
    local n = {};
    for key , value in pairs(t) do
        if not check[value] then
            n[key] = value
            check[value] = value
        end
    end
    return n
end