Ok, I'll bite. From the article:<p><pre><code> Now let's see how combinators (which we discussed in the previous blog
posting) might make doing some of these computations easier.
</code></pre>
So, how are they defined in the previous blog posting?<p><pre><code> A combinator is an atomic operation on a cell of a database that is
associative and preferably commutative.
</code></pre>
No, it's not. A combinator is a function with no free variables. Even the example is wrong:<p><pre><code> "Add(n)" is an example of a simple combinator; it adds n to whatever
number is in the cell.
</code></pre>
If "Add" was a combinator, the cell would have to be one of the parameters of "Add". Otherwise, the cell is a free variable.<p>To be clear, I'm just complaining about the misuse of the term "combinator", since it's a word with a strict mathematical definition and no other common-language interpretation (like "function" or "operation" have). I'm not commenting on the actual content of the article.
I found this to be a remarkably bad article. Out of this you'd learn nothing whatsoever about what it takes to build a moderate-scale (10 million pages) never mind large-scale web crawler.