string blueprint api

-- Blueprint manager API
-- by CrispyPin
layer_sep = "--"

blueprint = {}
keys = {}

function string:split(delimiter)
    -- stolen from jaredallard
    local result = {}
    local from  = 1
    local delim_from, delim_to = string.find(self, delimiter, from)
    while delim_from do
        table.insert(result, string.sub(self, from , delim_from-1))
        from = delim_to + 1
        delim_from, delim_to = string.find(self, delimiter, from)
    end
    table.insert(result, string.sub(self, from))
    return result
end

local function join(strA, strB)
    return table.concat({strA, strB}, "")
end

local function loadLayer(data)
    bp = {}
    row = {}
    x = 1
    y = 1
    for i = 1, string.len(data) do
        b = string.sub(data, i, i)
        if b == "\n" then
            bp[y] = row
            row = {}
            x = 1
            y = y + 1
        else
            row[x] = b
            x = x + 1
        end
    end
    return bp
end

function loadBlueprint(filePath)
    f = fs.open(filePath, "r")
    if f == nil then
        return false
    end
    while true do
        local data = f.readLine()
        if data == "--" then
            break
        end
        local k = string.sub(data, 1, 1)
        local id = string.sub(data, 3)
        keys[k] = id
    end
    rawBlueprint = f.readAll()
    print(rawBlueprint)
    f.close()
    local layers = string.split(rawBlueprint, join(join("\n", layer_sep), "\n"))
    for L = 1, table.maxn(layers) do
        blueprint[L] = loadLayer(layers[L])
    end
    return true
end

function getBlock(x, y, layer)
    return keys[blueprint[layer][y][x]]
end

function getFootprint()
    -- returns width, length
    return table.maxn(blueprint[1][1]), table.maxn(blueprint[1])
end

function getLayers()
    return table.maxn(blueprint)
end