Tag: web development

When monospace fonts aren’t: The Unicode character width nightmare

I don’t deal with Unicode and other character encoding on the daily basis, but when I do, I need every piece of information that has been written on the subject.  Hence the link to this interesting issue :

As long as you stick to precomposed Unicode characters, and Western scripts, things are relatively straightforward. Whether it’s A or Å, S or Š – so long as there are no combining marks, you can count a single Unicode code point as one character width. So the following works:

	aeioucsz
	áéíóúčšž

Nice and neat, right?

Unfortunately, problems appear with Asian characters. When displayed in monospace, many Asian characters occupy two character widths.

Latency Numbers Every Programmer Should Know

latency

I’m saving this here for current and future generations of programmers:

Latency Comparison Numbers
--------------------------
L1 cache reference                            0.5 ns
Branch mispredict                             5   ns
L2 cache reference                            7   ns             14x L1 cache
Mutex lock/unlock                            25   ns
Main memory reference                       100   ns             20x L2 cache, 200x L1 cache
Compress 1K bytes with Zippy              3,000   ns
Send 1K bytes over 1 Gbps network        10,000   ns    0.01 ms
Read 4K randomly from SSD*              150,000   ns    0.15 ms
Read 1 MB sequentially from memory      250,000   ns    0.25 ms
Round trip within same datacenter       500,000   ns    0.5  ms
Read 1 MB sequentially from SSD*      1,000,000   ns    1    ms  4X memory
Disk seek                            10,000,000   ns   10    ms  20x datacenter roundtrip
Read 1 MB sequentially from disk     20,000,000   ns   20    ms  80x memory, 20X SSD
Send packet CA->Netherlands->CA     150,000,000   ns  150    ms

Notes
-----
1 ns = 10-9 seconds
1 ms = 10-3 seconds
* Assuming ~1GB/sec SSD

Credit
------
By Jeff Dean:               http://research.google.com/people/jeff/
Originally by Peter Norvig: http://norvig.com/21-days.html#answers

Contributions
-------------
Some updates from:                      https://gist.github.com/2843375
Great 'humanized' comparison version:   https://gist.github.com/2843375
Visual comparison chart:                http://i.imgur.com/k0t1e.png
Nice animated presentation of the data: http://prezi.com/pdkvgys-r0y6/latency-numbers-for-programmers-web-development/

This is a copy-paste of this gist, referenced from this blog post. Read and share both, for the better world.

On full stack developers

I came across an excellent blog post on full stack developers – “The full stack developer is a myth“.  I do much agree on what is being said there.  Firstly, the stack itself.

Non-exhaustive list of a technical stack layers and components
Non-exhaustive list of a technical stack layers and components

Secondly, on the problem:

A full stack developer is a myth not because none exist, but because the term is meaningless. It’s no different from a coding ninja or rockstar, but at least everyone knows those terms don’t actually mean anything.

Even limiting the term to a more specific context like web stack or mobile stack, you’d still get quite a bit of technology for a single person.  And yes, it’s changing a lot and fast too!

Every year there are new components added to each layer and every couple of years there’s a new layer added to it. Is it really reasonable to put out job applications asking for a full stack developer? It’s not only unreasonable, it’s stupid. Particularly when you start looking for one person who’s an expert in security, web development, UX, and servers; and this isn’t at all an uncommon expectation.

More so, there is a geographical component to this as well.  If you are in a small country like Cyprus, with very few technical establishments, even further down simplifying the stack won’t help you much.  Finding a web developer with good knowledge of HTTP, HTML, CSS, JavaScript, PHP, and MySQL is already a challenge.   And that’s like three or four layers…

11 Highly Underrated Plugins for WordPress

I came across this list of 11 highly underrated plugins for WordPress.  I wouldn’t go as far as call of them highly underrated, as some of them are rather highly rated.  But that’s not the point.  I wanted to share the list especially for these three: