Set Variables And Tables With Function

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Instead of ensuring only the existence of an already created table, this function overwrites any given Table/Name -- as expected I think. And thanks to the fact that table-arguments are given by reference, you can use setvar() for any local table too.

function setvar(Table,Name,Value)



-- Table (table, optional); default is _G

-- Name (string); name of the variable--e.g. A.B.C ensures the tables A

--   and A.B and sets A.B.C to <Value>.

--   Using single dots at the end inserts the value in the last position

--   of the array--e.g. A. ensures table A and sets A[table.getn(A)]

--   to <Value>.  Multiple dots are interpreted as a string--e.g. A..B.

--   ensures the table A..B.

-- Value (any)

-- Compatible with Lua 5.0 and 5.1



   if type(Table) ~= 'table' then

      Table,Name,Value = _G,Table,Name

   end



   local Concat,Key = false,''



   string.gsub(Name,'([^%.]+)(%.*)',

      function(Word,Delimiter)

         if Delimiter == '.' then

            if Concat then

               Word = Key .. Word

               Concat,Key = false,''

            end

            if type(Table[Word]) ~= 'table' then

               Table[Word] = {}

            end

            Table = Table[Word]

         else

            Key = Key .. Word .. Delimiter

            Concat = true

         end

      end

   )



   if Key == '' then

      table.insert(Table,Value)

   else

      Table[Key] = Value

   end

end

Tests:

> Test = {}

> setvar(Test,'Index',1)

> setvar(Test,'Index.',22)

> setvar(Test,'Index.Index',333)

> table.foreach(Test,print)

Index   table: 0x689668

> table.foreach(Test.Index,print)

1       22

Index   333

>

> setvar(Test,'Index.Index.',4444)

> setvar(Test,'Index.Index.',4444)

> setvar(Test,'Index..',55555)

> setvar(Test,'Index..Index',666666)

> setvar(Test,'Index..Index.',7777777)

> setvar(Test,'Index..Index..',88888888)

> table.foreach(Test,print)

Index..Index..  88888888

Index.. 55555

Index   table: 0x689668

Index..Index    table: 0x684258

> table.foreach(Test.Index,print)

1       22

Index   table: 0x686270

> table.foreach(Test['Index..Index'],print)

1       7777777

>

> setvar(Test,'.Index',999999999)

> table.foreach(Test,print)

Index..Index..  88888888

Index.. 55555

Index   999999999

Index..Index    table: 0x684258

>

> setvar(Test,'',0)

> table.foreach(Test,print)

1       0

Index..Index..  88888888

Index..Index    table: 0x684258

Index   999999999

Index.. 55555

--MarkusHuber