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Journal Journal: Chronicle: Had a problem conceptualizing recursion in Java

I'm reading Java: A Beginner's Guide by Herbert Schildt. Schildt really is good. The lessons are smooth, with small complete examples of everything, explanations, and learning in steps, that is, each chapter builds on what was learned in the past. It's not just a bunch of concepts thrown together.. Here's one case where the O'reilly book just didn't do the job. It was good, but not for learning (reviewing, perhaps.)

I'm typing in every example, skipping the comments though. Also, changing names when they use plurals. An array should be named num, not nums, because each member is an instance of a num. It acts as a collections of nums, but it is not what it is. It's the J/P thing again. In databases, which is J territory, it should clearly be singular. Each record is an instance of the singular object (table.) And, people who think of tables in the plural often come up with terrible deigns and write horrible queries. Their using the database to support a specific process (which always changes, anyway) and not to hold data. They never learn. But i digress. Programs are about getting something done, so, it is more likely it should be named in the plural. I guess i'm in the wrong here. Though, as my code is for me (as opposed to if i was on a team), i'm going to follow my own preference.

In the Self Test for Chapter 6, question 6 is: Write a recursive method that displays the contents of a string backwards. I hit a mental block with that yesterday and just couldn't get it right. I was amazed (read: horrified) that such a small thing could be so hard. I ought to be able to (know what i need to do to) write that in seconds. After some fumbling over char vs String, it was time to go home. Today i approached the code and fixed it in just a few minutes.

class test06
{
  static String backward(String a)
  {
    if(a.length() == 1) return a;

    return a.substring(a.length() - 1) + backward(a.substring(0, a.length() - 1));
  }

  public static void main(String arg[])
  {
    System.out.println(backward("abcdef"));
  }
}

When i first got the question, i misunderstood it. I saw his answer and realized i misread it, so i tried this. Compared to his answer, he cheats. He used .charAt() to print out one char at a time from within the method. Granted, the book does that at this point, but this one is truer. And, i need something to be proud about.

But why did it take me so long? At first, i assumed its because i'm not used to Java, recursion is silly in this case, and i don't usually do recursion. But that's not true. I had a problem conceptualizing it, its effective, and i do it occasionally in SQL. But there's the answer. I do it in SQL.

Recursive CTEs are a pain. While more versatile than Oracle's hierarchical queries (which have a number of their own benefits), they are also confusing to learn. At some point it clicks though, and then its just a matter of keeping things straight in your head. However, in SQL's recursion the inner most level is also the final level. Outside of SQL, the opposite is true.

It's convenient to have blame it on SQL, though i know it's not true. Embarrassing as it is, i hit a mental block on the concept. Nonetheless, SQL likely had something to do with my confusion. I love these "easy" tests.

User Journal

Journal Journal: Well, this should be fun... 3

I went to SlashCode.com and saw there was a link for the code that runs Slashdot (well, probably several versions ago). Fine. I have a file called Bundle-Slash-2.5.2.tar.gz . There's a link for instructions, BUT it's a dead link.

I wonder how long it will take before I have something useful?

If I can get it running, I'll let you all know... Pudge, if you're reading this... A little guidance would be greatly appreciated. :)

User Journal

Journal Journal: Rant: Why i hate Java (simple, old debate) 4

Why do i hate Java? (And C too.) retardedNames, case sensitivity, offsets treated like indexes. These are examples of where programmers had good ideas but then unfortunately designed them into a language.

0 is not a number. A number represents a quantity and 0 is not a quantity. You don't declare an array less one because 0 is a number. However, it is treated as a number for convenience. Why then refer to an index in an array with 0 first? Okay, okay, i know. It's because the variable is just a pointer, and the index is really an offset. So then why use an offset to index an array? Seriously. In how many cases do you treat the offset as an index. And in how many do you treat it like an offset? I thought so.

Then there's the whole = vs ==. Debate over whether = should set or compare is understandable. Personally, i would never have used = to set, because most people use it to demonstrate equality. Not to test it, but to demonstrate it. As in any math equation we teach children. With that in mind, i would think it was more likely to be used to test equality rather than set it. Furthermore, pick the odd operator out: =, +=, -=, *=, /=. ^=. Yeah, yeah, those are for convenience. But how many times have you mistaken the double-character operator for anything else. Yes, but they have another operator that makes it obvious. Exactly. Isn't == obviously setting without an operation. x += y adds y to x then sets. x -= y subtracts y from x then sets. So, x == y should equal y to x then set. Slightly bumpy because it sets x to y and not vice versa, but its really easy to understand. And, earlier languages did it with :=. Same thing.

BASIC used = for both. Noone used LET outside of teaching. Regardless, context defined it anyway. Context is not available in Java because it allows you do do nifty things like increment an array offset while setting it. So, no context. Of course, this leads to bugs and the niftiness is often considered bad practice, but isn't it cool that we can do it?

I've seen absolute morons coding in BASIC. But never once had i seen them use = to do what they didn't intend. You know why? Because its impossible! Context rules. On the same note, i've read about talented programmers who made the mistake in C(++).

Prefix and postfix ++ and -- are a little different. They are not obvious (until you know what they do), and other than errors in logic, they are used as intended. They break context, per se, but that is what they are designed to do. Applying this to the poor = sign is just plain ridiculous.

Seriously, why are these things done when they are counterintuitive, prone to bugs, and bad practice? Were the designers brain dead, or just 31337 h4x0rz that hadn't grown up yet? Or, is everyone so blind to this because they never made this mistake.

Okay, the languages weren't designed inasmuch as they just ended up being used. But why? Was it because the pros outweighed the cons? Or was it because programmers actually like this nonsense?

User Journal

Journal Journal: Line: There's an AP (app) for that.

We need something done tomorrow. We're off tomorrow. The Asia/Pacific (AP) team is in tomorrow. So, need it done tomorrow? There's an AP (app) for that.

Well, it was funny when i thought of it...

User Journal

Journal Journal: Thanks, Obama! 37

Talking to a Caribbean-based business acquaintance this week reminded me that, no matter my feelings for the Obama administration, I will be eternally grateful that he's taken Cuba off the table. Because in the pantheon of stupid american wedge issues, the Cuban embargo is near-lock for the title IMO.

Bonus conspiracy fun: The lifting of the embargo, and its timing could be seen as a nice little spoiler for the only 2 GOP candidates who have any shot at beating Hillary next year, Bush and Rubio. Most of the other candidates can choose a wide range of answers when presented with questions on the topic, whereas the Floridians actually have serious history and ties on this, making finessing the issue that much harder.

Oh, and before someone thinks they're clever by telling me that President Perry or whoever would just go back to the status quo faster than you can say "fuck you liberals!", good luck with that. The GOP only cared that it reliably delivered Florida's electoral votes, and it stopped doing that a good couple of cycles ago. It's dead, Jim.

User Journal

Journal Journal: Number Five 2

I just sent off for the fifth and, I hope, last pre-publication copy of Yesterday's Tomorrows. I was sure it would be finished a month ago, but there were problems printing it due to some of the illustrations being too high of a resolution. It took a month to get the fourth printed.

I can't decide whether or not to assign an ISBN to it, since the book may not be legal in all countries. What do you think? I only have three or four left, and a block of ten is $250. Should I use one? The only country besides the US that has bought my books was Great Britain, and very few there although the web site gets visits from all over the world.

I'm pretty sure I'll never sell a book in Australia, because they're crazy expensive down there; tariffs, probably.

Oh, if you want to read the copy of Huckleberry Finn at my site, better hurry because when I post Yesterday's Tomorrows I'll have to take the Twain book down to make space. It will be back up this fall when I renew my URL and upgrade my hosting level. When it's back up I'll have a version that's easy to read on a phone.

User Journal

Journal Journal: How to counteract rm -rf / in a few easy steps.

first off be prepared, have killall rm in innocent looking names on the systems you protect. one for every letter of the alphabet if you can take the time to do that, but failing that having wget will allow you to download killall to any directory your on, assuming you have a network machine with the capabilities of sharing killall, or a comparable program.

User Journal

Journal Journal: Chronicle: Yesterday's bike ride

Rode my bicycle yesterday for exercise, with intent to go to Meijers (The name, Meijer's Thrifty Acres, which people colloquial called "Meijers". The name has changed, removing the need for the possessive "s." Kids and sticklers now use the new name.) I did go there, stopping off at the Royal Oak Post Office en route.

The post office is a nice one. I used to have a PO Box there. They've since added inner doors to replace the gate locked at nighttime. The doors look nicer when closed, i guess, but also makes it look more office-like during regular business hours. The bike stand/rock was missing outside, so i used the railing on the accessibility ramp. It goes around like a hairpin, but gets more narrow in middle of the second half. Well, if whoever uses it can use the more narrow part, using the side of the excess shouldn't be an issue, should it?

Anyway, they're slow, but what government office isn't? When the guy two in front of me went up (without being called, to wait for the returning clerk, who asked if he was actually next when she came back) the guy in front of me went moved up. The line at the office is not straight. There is the counter and an open area for standing and leaving, then an island with a flat top and forms on the side. The line forms on the other side of the island and around the bend, where people usually wait to be called. So, both people in front of me were facing perpendicular to the direction i was facing. When two-in-front went up, one-in-front walked forward. I turn and got behind him, and he moved up just a little further. Obviously, he wanted room. So be it. I figured he might not kike Jews, so i didn't stare at him either. That is, i made sure to look away from him. He did his business and left. I needed only a minute, so i was out relatively quickly.

As i was beginning to ride away on my bike, he commented (while unlocking his car?) to me, "I never saw a rabbi on a bike before." I smiled and kept on riding. I still don't know what he meant by the statement or why he considered me a rabbi. Mayhap, he doesn't get out much. :)

Before i even got to Meijers, i was pooped, and realized i really needed the break before i could ride home. The stop at the post office elongated my trip more than expected, and i wasn't ready for that much exertion this summer, yet. I took my time in the store, including checking out the Italian section, and getting Turkish sun dried tomatoes. I may go back and grab some of the Pomi products (they had two, iirc) to see if they are that good.

On my way home, i evoked the same responses as usual. People stare at me biking. I think people stare at all bikers, or better put, intruders on their domain. Anyway, as i was riding down one street, i saw two boys playing a couple(?) blocks ahead. The first went inside. Seemed normal. I don't know if he saw me or not. The second saw me and ran inside too. Nope, not inside. As i passed by, i saw him hiding behind a bush. Did he think i might curse him or was he just afraid or shy? I wish could go back and ask. Or maybe watch a video online with comments. Hmm... bike cam, anyone? :)

User Journal

Journal Journal: Days Go By 1

The Offspring released a new album in 2012 and I didn't know until yesterday. There are implications to that I need to get sorted but now you know what I'm listening to all day while I work.

They have a newer song out which I heard on the radio, which is what clued me in that something had been done since Rise and Fall, Rage and Grace. (Which was the 'new album' in my brain until yesterday even though it's 5 or 6 years old. Not that that is a big deal. I also think of Seventh Son of a Seventh Son as 'new' Maiden and that came out in '88)

I may start streaming US radio stations to stay more aware of what is going on in music back home.

User Journal

Journal Journal: Chronicle: Warm office, but what can i do? (2) 2

Well, two ladies came by in response to the request, at least one of which looked like she was dressed for dinner. I ignored them when they first walked by until they specifically asked for my attention. I had no idea that was normal business attire and really didn't think they were there for me.

Well, they have no half walls and no wall would make the desk fall down. I said i'd be willing to give up that part of the desk, but it didn't look like that was an option. We discussed the closed vent and i mentioned that it bothered other people in the past and i didn't want to bother them now. As they continued questioning, my neighbor piped in with her past experience. Finally, they suggested they would have an engineer look at the vent. I tried making a joke by telling them they could attach a pipe to the vent and put it down my back (which wouldn't bother anyone else...) One of them forced a small giggle. I don't even need retrospect to realize it was poorly timed. My mistake was to not appreciate that no comment is better than a bad one.

As they spoke i realized the were standing and i was sitting. Not being their superior, etiquette would demand that i stand, and stand i did. It's not something i always remember to do, as so many people do not. This etiquette in not a gender thing, but a respect thing. Sitting while other stand and speak to you is considered haughty (or inconsiderate, at the very least), or so i have been taught. A lot of people either disagree or just don't care.

I did bring in a thermometer today, changing the battery with a March 2015 expiry. It was 74+ all morning. When they left i looked again and saw it got lower, Right now its 72.5. Weird.

[I used the word "as" too much. Also i need to work on flow, as opposed to a collection of related statements.]

User Journal

Journal Journal: Linux Genius 3

I have a file on my machine - render.conf

I just did the following:

        cp render.conf render-snap.conf
        mv render.conf render-main.conf
        mv render-snap.conf render.conf

And then I just laughed at myself for a bit. It made sense when I did it and as soon as I had I realized how stupid it was.

User Journal

Journal Journal: Chronicle: Killed smss.exe 4

I almost never reboot Windows at the office. It takes too long, requires turning off all the stuff the IT department uses to ruin my day, and wastes time getting things setup just right. Instead, i just hibernate, and bear the few minutes it takes to get back to normal. (Hmm.. very winteresting.)

This morning while "researching" why some system process (via Process Explorer) was hogging 200MB of memory, and tried restarting it. Luckily, it rejected the idea, and told me other processes relied on it. So, i clicked back to tree list, leaving it highlighted, and saw its progeny included smss.exe. Perhaps out of sheer ignorance, perhaps because i got it mixed up with sms.exe, i asked to restart it. Instant BSOD.

Come to think of it, that was really stupid. Firstly, killing the session manager would at best shut down the OS. But i should have researched it first. So silly. Please, laugh at me, heartily.

User Journal

Journal Journal: Rant: Warm office, but what can i do? 8

I really dislike the summer in the office. It gets warmer outside so the women start wearing less clothes. Then they complain the office is too cold. Really?! My water consumption went up this week, and i''ve been buying caffeinated drinks just to stay awake.

I have an air vent above me which was closed before i got here because the lady next cubicle over, who is very nice and sensible as long as she agrees with you, complained of being too cold. When i asked her about it, she said opening it would make her cold, require her to wear a sweater and socks (perish the thought!) and then take them off when she got outside, which would inconvenience her. About me, who gets much too hot and cannot take off my clothes, she offered me the ice pack she uses to keep her lunch cool, to place on my neck or in front or in back of my fan. I guess i'm just clothes-minded. Anyway, arguing with a coworker is not productive and only ends up in fights, if everyone stays employed. So, i'm looking for other solutions.

As our section of the cube farm is a set of four cubicles with their own walls, airflow is restricted. I made a request to maintenance to remove one of my walls or replace it with a half-wall (suggested by another clothes-challenged woman, who sits near a window (no windows can be opened)). That may allow for better air flow. The request went in yesterday, though i have to find out if that is the correct group to make the request to, and if this is allowed, or even if it would be approved.

In years past i've wondered why hot air made me uncomfortable and tired, yet outside i was fine. To wit, inside, at 72 i'm warm, 74 is uncomfortable, 76 is really uncomfortable and i am tired, and at 78 i've been known to blank out (depends on how tired i am). Outside, however, i can weather the 80s and love it. After reading and testing, i found the difference to be fresh air. I don't mind the heat, but the stale air. Take away my fresh air, and i'll need the air to be cooler. I'm assuming this is true for most people, though the range will differ.

Well, fresh air is out of the question here. The windows are closed, we're a few floors up, and the vent that would blow directly on to me has been closed. So, i need to be cooler. Iced and caffeinated drinks only work so much, cost a bit, and have other consequences. A personal air conditioner would seem best, but do those even exist? I mean, there are personal heaters which do the job well. But what about cooling the air? Fans do little more than move the air. I have a fan, but the walls of the cubicle stifle its already limited effect. There are sponge coolers that have mixed reviews. I'm looking for a(n impossible) air conditioner that would just blow the hot air under the cubicle wall (or the like), would be silent, and be powerful enough to cool me down. I don't need much more than that. Truthfully, any idea might work, as long as it is relatively noiseless and inconspicuous.

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