Execute Brain****/Lua

Execute Brain****/Lua is an implementation of Brainf***. Other implementations of Brainf***.

Execute Brain****/Lua is part of RCBF. You may find other members of RCBF at Category:RCBF.

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An implementation of a Brainf*** interpreter in Lua. <lang lua>memory = {0} --memory is bounded on one side, at 1

program = io.read() --loads an entire program at once, must not contain newlines

pointer = 1

instruction = 1

retpoints = {}

functions = { [">"] = function()

 pointer = pointer + 1
 if not memory[pointer] then memory[pointer] = 0 end

end, ["<"] = function()

 if pointer == 1 then error"Memory out-of-bounds!" end
 pointer = pointer - 1

end, ["+"] = function()

 memory[pointer] = memory[pointer] + 1

end, ["-"] = function()

 memory[pointer] = memory[pointer] - 1

end, ["["] = function()

 if memory[pointer] ~= 0 then
   table.insert(retpoints, instruction)
 else --if the pointer is zero, jump to the next close bracket
   while program:sub(instruction, instruction) ~= "]" do
     instruction = instruction + 1
   end
 end

end, ["]"] = function()

 if memory[pointer] ~= 0 then
   instruction = retpoints[#retpoints]
 else
   table.remove(retpoints)
 end

end, ["."] = function()

 io.write(string.char(memory[pointer]))

end, [","] = function()

 memory[pointer] = io.read():byte()

end} while instruction <= #program do

 local instr = functions[program:sub(instruction,instruction)]
 if instr then instr() end
 instruction = instruction + 1

end</lang>