cc-mek-scada/lockbox/util/stream.lua

local Queue = require("lockbox.util.queue");
local String = require("string");

local Stream = {};


Stream.fromString = function(string)
    local i = 0;
    return function()
        i = i + 1;
        return String.byte(string, i);
    end
end


Stream.toString = function(stream)
    local array = {};
    local i = 1;

    local byte = stream();
    while byte ~= nil do
        array[i] = String.char(byte);
        i = i + 1;
        byte = stream();
    end

    return table.concat(array);
end


Stream.fromArray = function(array)
    local queue = Queue();
    local i = 1;

    local byte = array[i];
    while byte ~= nil do
        queue.push(byte);
        i = i + 1;
        byte = array[i];
    end

    return queue.pop;
end


Stream.toArray = function(stream)
    local array = {};
    local i = 1;

    local byte = stream();
    while byte ~= nil do
        array[i] = byte;
        i = i + 1;
        byte = stream();
    end

    return array;
end


local fromHexTable = {};
for i = 0, 255 do
    fromHexTable[String.format("%02X", i)] = i;
    fromHexTable[String.format("%02x", i)] = i;
end

Stream.fromHex = function(hex)
    local queue = Queue();

    for i = 1, String.len(hex) / 2 do
        local h = String.sub(hex, i * 2 - 1, i * 2);
        queue.push(fromHexTable[h]);
    end

    return queue.pop;
end



local toHexTable = {};
for i = 0, 255 do
    toHexTable[i] = String.format("%02X", i);
end

Stream.toHex = function(stream)
    local hex = {};
    local i = 1;

    local byte = stream();
    while byte ~= nil do
        hex[i] = toHexTable[byte];
        i = i + 1;
        byte = stream();
    end

    return table.concat(hex);
end

return Stream;