TerrariLua V1

local sFile = fs.open("world", "w")
local chunk = 0
local termW, termH = term.getSize()
local midW, midH = math.floor(termW/2), math.floor(termH/2)
local xPos, yPos = 0, 51
local pDir = ">"
local blockinfo = {
["bedrock"] = 128,
["stone"] = 256,
["dirt"] = 4096,
["grass"] = 32,
["air"] = 32768
}
world = nil
local blocks = {}
blocks[0] = "bedrock"
blocks[1] = "bedrock"
for i = 2, 24 do
    blocks[i] = "stone"
end
for i = 25, 40 do
    blocks[i] = "dirt"
end
for i = 41, 49 do
    blocks[i] = "grass"
end
blocks[50] = "air"
function generateWorld()
    local sFile = fs.open("world", "w")
    --sFile.writeLine("{")
    for x = -midW - 3, midW + 3 do
        sFile.writeLine("  [" .. tostring(x) .. "] = {")
        for y = 1, 50 do
            sFile.writeLine("    [" .. tostring(y) .. "] = \"" .. tostring(blocks[math.random(y/1.2, y)]) .. "\",")
        end
        for y = 51, 100 do
            sFile.write("    [" .. tostring(y) .. "] = \"air\"")
            if y == 100 then
                sFile.writeLine("")
            else
                sFile.writeLine(",")
            end
        end
        if x == midW + 3 then
            sFile.writeLine("  }")
        else
            sFile.writeLine("  },")
        end
    end
    --sFile.writeLine("}")
    sFile.close()
end

function displayWorld()
    term.setBackgroundColor(colors.black)
    term.clear()
    term.setCursorPos(midW + 1, midH + 1)
    term.setBackgroundColor(colors.lightBlue)
    term.write(pDir)
    for x = xPos - midW, xPos + midW do
        for y = (yPos > 100 - midH) and 100 or yPos + midH, (yPos <= midH) and 1 or yPos - midH, -1 do
            if world[x][y] ~= "air" then
                term.setCursorPos(xPos + midW - x + 1, midH + yPos - y + 1)
                term.setBackgroundColor(blockinfo[world[x][y]])
                term.write(" ")
            end
        end
    end
end

function updateWorld()
    world = nil
    local lFile = fs.open("world", "r")
    loadstring("world = {\n" .. lFile.readAll() .. "\n}")()
    lFile.close()
    if not world[xPos - midW - 3] or not world[xPos + midW + 3] then
        local cFile = fs.open("world", "r")
        local temp = cFile.readAll()
        cFile.close()
        local sFile = fs.open("world", "w")
        if not world[xPos - midW - 3] then
            sFile.writeLine("  [" .. tostring(xPos - midW - 3) .. "] = {")
            for y = 1, 50 do
                sFile.writeLine("    [" .. tostring(y) .. "] = \"" .. tostring(blocks[math.random(y/1.2, y)]) .. "\",")
            end
            for y = 51, 100 do
                sFile.write("    [" .. tostring(y) .. "] = \"air\"")
                if y == 100 then
                    sFile.writeLine("")
                else
                    sFile.writeLine(",")
                end
            end
            sFile.writeLine("  },")
            sFile.writeLine(temp)
        elseif not world[xPos + midW + 3] then
            sFile.writeLine(temp .. ",")
            sFile.writeLine("  [" .. tostring(xPos + midW + 3) .. "] = {")
            for y = 1, 50 do
                sFile.writeLine("    [" .. tostring(y) .. "] = \"" .. tostring(blocks[math.random(y/1.2, y)]) .. "\",")
            end
            for y = 51, 100 do
                sFile.write("    [" .. tostring(y) .. "] = \"air\"")
                if y == 100 then
                    sFile.writeLine("")
                else
                    sFile.writeLine(",")
                end
            end
            sFile.writeLine("  }")
        end
        sFile.close()
    end
end

generateWorld()
while true do
    updateWorld()
    displayWorld()
    term.setCursorPos(1, 1)
    term.write(tostring(xPos) .. "," .. tostring(yPos))
    sleep(.05)
    local events = {os.pullEvent()}
    if events[1] == "key" then
        if events[2] == 200 then --up
            pDir = "^"
            if world[xPos][yPos + 1] == "air" then
                yPos = yPos + 1
            end
        elseif events[2] == 205 then --right
            pDir = ">"
            if world[xPos - 1][yPos] == "air" then
                xPos = xPos - 1
            end
        elseif events[2] == 208 then --down
            pDir = "v"
            if world[xPos][yPos - 1] == "air" then
                yPos = yPos - 1
            end
        elseif events[2] == 203 then --left
            pDir = "<"
            if world[xPos + 1][yPos] == "air" then
                xPos = xPos + 1
            end
        end
        if events[2] == 17 then
            pDir = "^"
        elseif events[2] == 30 then
            pDir = "<"
        elseif events[2] == 31 then
            pDir = "v"
        elseif events[2] == 32 then
            pDir = ">"
        end
        if events[2] == 45 then
            local changeB = "air"
            local oTemp = fs.open("temp", "w")
            local changeX, changeY = nil, nil
            local ready = false
            if pDir == "^" then
                changeX, changeY = xPos, yPos + 1
            elseif pDir == ">" then
                changeX, changeY = xPos - 1, yPos
            elseif pDir == "v" then
                changeX, changeY = xPos, yPos - 1
            elseif pDir == "<" then
                changeX, changeY = xPos + 1, yPos
            end
            if world[changeX][changeY] ~= "bedrock" then
                for line in io.lines("world") do
                    if line:sub(3, 4 + #tostring(changeX)) == "[" ..tostring(changeX) .. "]" then
                        ready = true
                    end
                    if ready and line:sub(6, 5 + #tostring(changeY)) == tostring(changeY) then
                        oTemp.writeLine("    [" .. tostring(changeY) .. "] = \"" .. changeB .."\",")
                        ready = false
                    else
                        oTemp.writeLine(line)
                    end
                end
                oTemp.close()
                oTemp = fs.open("temp", "r")
                local temp = oTemp.readAll()
                oTemp.close()
                local sFile = fs.open("world", "w")
                sFile.write(temp)
                sFile.close()
            end
        end
        if events[2] == 46 then
            local changeB = "stone"
            local oTemp = fs.open("temp", "w")
            local changeX, changeY = nil, nil
            local ready = false
            if pDir == "^" then
                changeX, changeY = xPos, yPos + 1
            elseif pDir == ">" then
                changeX, changeY = xPos - 1, yPos
            elseif pDir == "v" then
                changeX, changeY = xPos, yPos - 1
            elseif pDir == "<" then
                changeX, changeY = xPos + 1, yPos
            end
            if world[changeX][changeY] == "air" then
                for line in io.lines("world") do
                    if line:sub(3, 4 + #tostring(changeX)) == "[" ..tostring(changeX) .. "]" then
                        ready = true
                    end
                    if ready and line:sub(6, 5 + #tostring(changeY)) == tostring(changeY) then
                        oTemp.writeLine("    [" .. tostring(changeY) .. "] = \"" .. changeB .."\",")
                        ready = false
                    else
                        oTemp.writeLine(line)
                    end
                end
                oTemp.close()
                oTemp = fs.open("temp", "r")
                local temp = oTemp.readAll()
                oTemp.close()
                local sFile = fs.open("world", "w")
                sFile.write(temp)
                sFile.close()
            end
        end
    end
end