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Re:80 chars per line is great by ak217 on Monday March 25, 2013 @11:10AM (#5437369)
Yeah, but code readability has little to do with line width. I could show you perfectly unreadable code that fits in 80 characters because it's legitimately pre-indented by 40 and has to go to one word per line or shorten variable names to fit in 80, and wonderfully easy to read code that goes out to 160 (often because of some literal data that would otherwise just increase the vertical length).

Also, it's funny to me that people talk about horizontal line length impacting readability, but never seem to talk about vertical length impacting readability as well. To me it's critical to keep related code clustered vertically as closely as possible without too much brevity: having to scroll/split view to see related pieces of code incurs a cognitive overhead. Arbitrary line breakage imposed by the 80-character limit gets in the way of that. (And don't get me started about teams that treat this as a limit instead of a guideline.)

It's critical to give programmers the tools to make their code readable (good languages with good grammar and idioms), not arbitrary restrictions that try and fail to accomplish that indirectly.

Re:80 chars per line is great by ajross on Monday March 25, 2013 @11:55AM (#5437682)
> I could show you [...] wonderfully easy to read code that goes out to 160

I'm calling this bluff. No, you can't. If you actually have evidence I'd truly love to see it.

Ridiculous line length is actually one of the most reliable code smells I know. Seeing something like that, I can virtually guarantee that it's an OOP-gone-wild mess of needless abstraction, tightly coupled data structures spread across a dozen files. It's going to be a spaghetti mess of nested if() constructs used where clean data-driven logic would have been better. It will be filled with commented-out-code. And it will probably have indentation that lies, lined up in incorrect columns waiting to fool the developer.

Clearly you feel differently. Prove it. :)

Re:80 chars per line is great by ak217 on Monday March 25, 2013 @12:10PM (#5437780)
https://github.com/kislyuk/dmtk/blob/master/scripts/compareP...

Feel free to criticize. That code has lots of shortcomings. Compromised readability due to line length is not one of them.

Re:80 chars per line is great by ajross on Monday March 25, 2013 @12:59PM (#5438072)
You can't be serious. Check lines 388-400. Now, even ignoring the fact that github itself is chopping those lines because they're too long, they're simply not meaningfully readable. The ridiculous repetition (which is the proximate cause of those awful line lengths) totally obscures the meaning.

Note all the repeated use of this weird dictionary name "my_stats[condition][strand]". This thing appears, often multiple times, on ever line of that loop. You're telling me that this couldn't be made more readable by using a simple local "stats" reference name "st"? Repetition of expressions is the sign of lazy code, it's the same kind of thought process that gives us cut-and-paste bugs.

Note likewise the repated use of "kc_stats[condition]". Same deal. Same treatment.

Note likewise the oddball commented out line (assigning a tuple of m2_ci_lo_fwd, m2_ci_hi_fwd) which is disabled without explanation. Remember my list of attendant symptoms?

And, on the design side: note the mean/median/stdev calls. Those are generally pretty well-defined properties of "sets". Why is there a "Metric" postpended to the method names needlessly? Surely the reader would understand "st.stdev()" already, right? And why do the methods take five named parameters?. That's insane -- they should take zero. It looks like this is trying to pass in some extra "stuff" (maybe to control some side effects, or to filter the data) to what should be an idempotent operation on a fixed piece of data. If you have to filter, or if the object does some extra counting or whatever, those should be set up on the data ahead of time.

This code is crap. Sorry.

Re:80 chars per line is great by ajross on Monday March 25, 2013 @01:42PM (#5438394)
Just because I'm feeling bored today, here is that same loop (around line 388) "cleaned up" to work inside 80 columns. I added a "metricGenrator" abstraction to the API because it seemed like a sane addition to clean up the "too many arguments to mean()" problem, but all other changes are is pure syntax. I dare you to argue that this isn't more readable than the original:

      my_stats = {'Modified': {'+': {}, '-': {}}, 'Control': {'+': {}, '-': {}}}
      for condition in 'Modified', 'Control':
        for strand in '+', '-':
          st = my_stats[condition][strand]
          kc = kc_stats[condition]
          kc = kc.metricGenerator(metric, ref_pos=ref_pos, trim=opts.exp_trim,
                                  coverage_ceiling=opts.coverage_ceiling,
                                  strand=strand)
          st['mean'] = kc.mean()
          st['median'] = kc.median()
          off = st['stdev'] = kc.stdev()

          if use_se:
            kc.setOpts(ref_pos, metric, trim=0.0,
                       coverage_ceiling=opts.coverage_ceiling, strand=strand)
            off /= sqrt(len(kc._getMetricData()))

          st['spread_lo'] = st['mean'] - off
          st['spread_hi'] = st['mean'] + off
          my_report_row.extend(st['mean'], st['median'], st['stdev'],
                               st['spread_lo'], st['spread_hi'],
                               st['coverage']])
Re:80 chars per line is great by arh68 on Monday March 25, 2013 @03:39PM (#5439195)
I don't know if this was easy or quick for you (less than an hour, in any case), but you seem to prove the parent correct: "That code has lots of shortcomings. Compromised readability due to line length is not one of them." Maybe you're simply an amazing programmer, but to jump in and refactor a small bit of code deep inside something you've never seen before proves to me that the initial code was indeed readable.

In either case, both examples are literally geometrically square, which I think drives readability more than line width. When the long lines poke out and don't relate to other long lines, it's hard to read. If all the lines are long and share structure, it's just verbose, but reasonably easy to read. With that perspective, I'd say the parent's code isn't a great example of long-line code: it doesn't demonstrate a _need_ for 160 chars; I'll agree with you.

Re:80 chars per line is great by ajross on Monday March 25, 2013 @11:16PM (#5441167)
I started typing a longer response, but honestly I think the clearest answer here is just sarcasm:

Some of us have a higher standard for "readable" code than "can be refactored so that it doesn't suck". :)

Re:80 chars per line is great by thangalin on Monday March 25, 2013 @01:31PM (#5438316)
The code is illegible for a number of reasons:

* Duplication everywhere.

* No internal comments indicating the code's purpose.

* Long functions with too much nesting.

* Lack of constants.

* Indenting by 4 spaces (instead of 2).

* Lines like 316-320 and 326-335 should line break and indent after the first open parenthesis to avoid huge whitespace.

* Inconsistent line break usages for long lines.

* Line 412, for example, should line break at "ref_pos".

The code has many shortcomings, including readability due to extreme line length.

Re:80 chars per line is great by Hytosys on Monday March 25, 2013 @12:59PM (#5438074)

  self.opts.modified_positions_fwd = [ int(p) for p in self.opts.modified_positions_fwd.split(",") ] if self.opts.modified_positions_fwd != None else []
Without explicitly attacking Python's syntax, I had to horizontally scroll left and right multiple times to understand the entire impact of this statement.

Both yours and my claims are anecdotal. Unfortunately I don't know of many research studies, though I'm sure some has been done for this issue in typography.

Re:80 chars per line is great by ak217 on Tuesday March 26, 2013 @06:58AM (#5442350)
You're right, those lines (and a few others in that file) aren't good. For the ones you cited, that run-on if really is too far out. If I was writing them today, I'd break it up into an if..else.
Re:80 chars per line is great by jonnytran on Monday March 25, 2013 @01:21PM (#5438237)
> people talk about horizontal line length impacting readability, but never seem to talk about vertical length

This is why I think it's absurd that we still use flat file text editors to code. I don't care about how functions are laid out in the file. As you said, I care about their semantic relatedness. That may vary by concern. It's almost like I want to tag each function with the features/concerns that it addresses. Then I'd like to be able to view each tag on its own, and have all its constituent parts (functions, modules, classes, etc.) laid out in a way that makes sense. Maybe that's stacked vertically, maybe side by side, or maybe something else. I'd be able to switch between views at will. Each feature branch would probably have its own view.

This would have the side benefit that a function with many tags is a new smell, but more meaningful than character or line length.

The only people I know of who are even attempting to address these issues are Brett Victor, Jonathan Edwards, and the Light Table people.