Paginate helper library in Lua (for the Playdate)

Paginate.lua

Paginate = {}

function Paginate.read(filename)
    local lines = {}
    local file = File.open(filename, File.kFileRead)
    local line = file:readline()
    while line do
        table.insert(lines, line)
        line = file:readline()
    end
    file:close()
    return lines
end

function Paginate.wrap(lines, width)
    local font = Graphics.getFont()
    local spaceWidth = font:getTextWidth(" ")

    local result = {}
    for _, line in ipairs(lines) do
        local currentWidth = 0
        local currentLine = ""
        if line == "" then
            table.insert(result, line)
        else
            for word in line:gmatch("%S+") do
                local wordWidth = font:getTextWidth(word)
                if currentWidth == 0 then
                    currentWidth = wordWidth
                    currentLine = word
                else
                    local newLine = currentLine .. " " .. word
                    local newWidth = font:getTextWidth(newLine)
                    if newWidth >= width then
                        table.insert(result, currentLine)
                        currentWidth = wordWidth
                        currentLine = word
                    else
                        currentWidth += newWidth
                        currentLine = newLine
                    end
                end
            end
            if currentWidth ~= 0 then
                table.insert(result, currentLine)
            end
        end
    end
    return result
end

function Paginate.window(text, start_index, rows)
    local result = {}
    for index = 0, rows do
        if start_index + index > #text then
            break
        end

        table.insert(result, text[start_index + index])
    end
    return table.concat(result, "\n")
end

function Paginate.paginate(lines, rows)
    local result = {}
    local currentLine = {}
    for _, line in ipairs(lines) do
        if line == "" then
            if #currentLine ~= 0 then
                table.insert(result, table.concat(currentLine, "\n"))
                currentLine = {}
            end
        else
            if #currentLine >= rows then
                table.insert(result, table.concat(currentLine, "\n"))
                currentLine = {line}
            else
                table.insert(currentLine, line)
            end
        end
    end
    if #currentLine ~= 0 then
        table.insert(result, table.concat(currentLine, "\n"))
        currentLine = {}
    end
    return result
end

function Paginate.process(text, width, height)
    local lines = {}
    for line in text:gmatch("[^\r\n]+") do
        table.insert(lines, line)
    end
    local wrapped = Paginate.wrap(lines, width)
    return Paginate.paginate(wrapped, Paginate.getRows(height))
end

function Paginate.getRows(height)
    local font = Graphics.getFont()
    local leading = font:getLeading()
    return height // (font:getHeight() + leading)
end