There are many things that puzzle me about common web design. One ofthe biggest thing is this: why do so many sites reduce the font sizeof their main content? This is the single largest readability problemthat I run into on the web. (For some reason this seems to be especiallyprevalent on blogs.)

I see it over and over again, in CSS like 'font-size:small', 'font-size: 80%', 'font: normal 76%/

I could talk about aesthetics; I could talk about line noise andreadability; but for me it ultimately comes down to one thing: datastructures.

Namely, I find it very hard to write perl code of any depth withoutrunning headlong into the fact that Perl's 'collection' types (arraysand hashes) can't contain themselves. All they can contain is scalars(strings, numbers, and references).

For example, recently I was writing a program to mass-query the SBLDNS blocklist

Python has recently (at least for some values of recently) grown 'list comprehensions' ,which let you easily iterate over a list to transform or selectentries (or both). List comprehensions can be thought of as syntacticsugar for map and filter operations, but they're actually morepowerful.

One reason is that you can write a multilevel list comprehension,which effectively iterates over multiple levels of lists. Take thecase where you have a list within a list and want to return all of thelow-