Serel seems to wrap contents returned in the `body` filter in HTML tags

[marcamillion]

When I request a specific question, and add the filter(:withbody) attribute to the call, it seems that the results returned in .body include HTML tags.

Here is an example of the API call result:

> w = Serel::Question.filter(:withbody).find(11227809)
[INFO][2013-04-08 00:39:17] Making request to /2.0/questions/11227809?filter=withbody&site=stackoverflow&key=some_key%28%28
 => [#<Serel::Question:70352730636420 @question_id=11227809, @last_edit_date=2013-04-06 14:31:38 -0500, @creation_date=2012-06-27 08:51:36 -0500, @last_activity_date=2013-04-06 14:31:38 -0500, @score=4262, @answer_count=9, @accepted_answer_id=11227902, @protected_date=2012-06-28 23:02:46 -0500, @body=<p>Here is a piece of C++ code that shows some very peculiar performance. For some strange reason, sorting the data miraculously speeds up the code by almost 6x:</p>

<pre class="lang-cpp prettyprint-override"><code>#include &lt;algorithm&gt;
#include &lt;ctime&gt;
#include &lt;iostream&gt;

int main()
{
    // Generate data
    const unsigned arraySize = 32768;
    int data[arraySize];

    for (unsigned c = 0; c &lt; arraySize; ++c)
        data[c] = std::rand() % 256;

    // !!! With this, the next loop runs faster
    std::sort(data, data + arraySize);

    // Test
    clock_t start = clock();
    long long sum = 0;

    for (unsigned i = 0; i &lt; 100000; ++i)
    {
        // Primary loop
        for (unsigned c = 0; c &lt; arraySize; ++c)
        {
            if (data[c] &gt;= 128)
                sum += data[c];
        }
    }

    double elapsedTime = static_cast&lt;double&gt;(clock() - start) / CLOCKS_PER_SEC;

    std::cout &lt;&lt; elapsedTime &lt;&lt; std::endl;
    std::cout &lt;&lt; "sum = " &lt;&lt; sum &lt;&lt; std::endl;
}
</code></pre>

<ul>
<li>Without <code>std::sort(data, data + arraySize);</code>, the code runs in <strong>11.54</strong> seconds.</li>
<li>With the sorted data, the code runs in <strong>1.93</strong> seconds.</li>
</ul>

<hr>

<p>Initially I thought this might be just a language or compiler anomaly. So I tried it in Java:</p>

<pre class="lang-java prettyprint-override"><code>import java.util.Arrays;
import java.util.Random;

public class Main
{
    public static void main(String[] args)
    {
        // Generate data
        int arraySize = 32768;
        int data[] = new int[arraySize];

        Random rnd = new Random(0);
        for (int c = 0; c &lt; arraySize; ++c)
            data[c] = rnd.nextInt() % 256;

        // !!! With this, the next loop runs faster
        Arrays.sort(data);

        // Test
        long start = System.nanoTime();
        long sum = 0;

        for (int i = 0; i &lt; 100000; ++i)
        {
            // Primary loop
            for (int c = 0; c &lt; arraySize; ++c)
            {
                if (data[c] &gt;= 128)
                    sum += data[c];
            }
        }

        System.out.println((System.nanoTime() - start) / 1000000000.0);
        System.out.println("sum = " + sum);
    }
}
</code></pre>

<p>with a similar but less extreme result.</p>

<hr>

<p>My first thought was that sorting brings the data into cache, but my next thought was how silly that is because the array was just generated.</p>

<p>What is going on? Why is a sorted array faster than an unsorted array? The code is summing up some independent terms, the order should not matter.</p>
, @title=Why is processing a sorted array faster than an unsorted array?, @tags=["c++", "performance", "optimization", "language-agnostic", "branch-prediction"], @view_count=222854, @link=http://stackoverflow.com/questions/11227809/why-is-processing-a-sorted-array-faster-than-an-unsorted-array, @is_answered=true @owner=#<Serel::User:70352730647660>>] 

This is the question.body as seen on Stack Overflow if you go to the question and hit edit and copy the actual question itself:

Here is a piece of C++ code that shows some very peculiar performance. For some strange reason, sorting the data miraculously speeds up the code by almost 6x:

<!-- language: lang-cpp -->

    #include <algorithm>
    #include <ctime>
    #include <iostream>

    int main()
    {
        // Generate data
        const unsigned arraySize = 32768;
        int data[arraySize];

        for (unsigned c = 0; c < arraySize; ++c)
            data[c] = std::rand() % 256;

        // !!! With this, the next loop runs faster
        std::sort(data, data + arraySize);

        // Test
        clock_t start = clock();
        long long sum = 0;

        for (unsigned i = 0; i < 100000; ++i)
        {
            // Primary loop
            for (unsigned c = 0; c < arraySize; ++c)
            {
                if (data[c] >= 128)
                    sum += data[c];
            }
        }

        double elapsedTime = static_cast<double>(clock() - start) / CLOCKS_PER_SEC;

        std::cout << elapsedTime << std::endl;
        std::cout << "sum = " << sum << std::endl;
    }

 - Without `std::sort(data, data + arraySize);`, the code runs in **11.54** seconds.
 - With the sorted data, the code runs in **1.93** seconds.

----------

Initially I thought this might be just a language or compiler anomaly. So I tried it in Java:

<!-- language: lang-java -->

    import java.util.Arrays;
    import java.util.Random;

    public class Main
    {
        public static void main(String[] args)
        {
            // Generate data
            int arraySize = 32768;
            int data[] = new int[arraySize];

            Random rnd = new Random(0);
            for (int c = 0; c < arraySize; ++c)
                data[c] = rnd.nextInt() % 256;

            // !!! With this, the next loop runs faster
            Arrays.sort(data);

            // Test
            long start = System.nanoTime();
            long sum = 0;

            for (int i = 0; i < 100000; ++i)
            {
                // Primary loop
                for (int c = 0; c < arraySize; ++c)
                {
                    if (data[c] >= 128)
                        sum += data[c];
                }
            }

            System.out.println((System.nanoTime() - start) / 1000000000.0);
            System.out.println("sum = " + sum);
        }
    }

with a similar but less extreme result.

----------

My first thought was that sorting brings the data into cache, but my next thought was how silly that is because the array was just generated.

What is going on? Why is a sorted array faster than an unsorted array? The code is summing up some independent terms, the order should not matter.

How do I get the body of the question (and I assume the answer) to be returned with no HTML tags, just markdown as included in the question itself?