The 2nd Monitor

12:00 AM

BTW this is what the ++ operator does now:

    public static Fraction operator ++(Fraction fraction)
    {
        return fraction + 1;
    }

mjolka

yay :)

what's GetHashCode currently looking like?

Mat's Mug

would this make sense?

    public override int GetHashCode()
    {
        return Simplify().ToFloat().GetHashCode();
    }

Alex L

Why is this room named "The 2nd Monitor"? What's the history behind that?

Mat's Mug

7

Q: What should be the name of our main chatroom?

Our main chat room is currently called Code Review General Room, with "General discussion about Code Review." for a description. I propose The Zombie Hunters' Lounge, but I'd like the community to post their ideas here (1 per post, include why it's the best name), the one with the highest number...

Dan Lyons

The first monitor was a CRT

or that, though it's the fourth monitor for me :o

Mat's Mug

12:05 AM

@AlexL I just came up with it, and since meta-activity was quite low back then after a while I just decided to call it that ;)

mjolka

i was thinking (after simplifying) long x = (((long) _numerator) << 32) | _denominator; return x.GetHashCode();

Alex L

@Mat'sMug Wow, kinda cool :)

Mat's Mug

@mjolka bit-shifting o.O ...I'm going to have to look into that at one point.

Dan Lyons

there's no way dealing with other people and implementing functionality you disagree with are that small in the pie

sometimes it feels like they should be the 49% :P

mjolka

"implementing underspecified functionality" should be on there

Mat's Mug

12:12 AM

@mjolka seriously, ...that's a couple notches above my level :/

Dan Lyons

staying awake in meetings should be there too :)

mjolka

@Mat'sMug the bit-shifting?

Mat's Mug

and the binary or with _denominator ...I don't get the why.

all I've used binary operators for, was for flag enums :/

mjolka

well you've got two 32-bit values, so let's treat them like one 64-bit value

because some good folks already figured out GetHashCode for a 64-bit value

Mat's Mug

hence the cast to long

Dan Lyons

12:14 AM

you would get slightly more deterministic results since you're avoiding the floating point

mjolka

right

Mat's Mug

but why shift 32 bits?

mjolka

so we (arbitrarily) pick numerator to be the left-most 32-bits

Mat's Mug

oh

Dan Lyons

that's just packaging - you put one value in the top 32 bits and the other value in the bottom 32 bits

mjolka

12:16 AM

right, so if numerator is xx...xx, we shift it 32-bits to the left to get xx..xx00..00

Mat's Mug

ok

mjolka

now set the right-most bits by bitwise-or'ing

and then assume that whoever wrote long.GetHashCode knew more than we do about hashing 64-bit values :)

Dan Lyons

you could do it with addition, too

(((long) _numerator << 32) + _denominator) should do the same thing

Mat's Mug

so hold on, we have an Int32 which we cast to an Int64, leaving the left-most 32 bits useless, so we shift it 32 bits to the left.

mjolka

yep

Mat's Mug

12:19 AM

then the bitwise or... ...fries my brain.

mjolka

let's pretend int is 2-bits and long is 4-bits

Mat's Mug

lol ok

mjolka

(i cannot type this morning)

Mat's Mug

so we cast Int2 to Int4

and 0011 << 2 becomes 1100

mjolka

say _numerator is ab (in binary), _denominator is xy

^ yes

(long) numerator is 00ab

Mat's Mug

12:20 AM

yeah

mjolka

((long) numerator) << 2 is ab00

Mat's Mug

still there

oh

mjolka

((long) numerator) << 2 | xy is abxy

Mat's Mug

click

mjolka

:)

Dan Lyons

12:21 AM

ya you just smooshed [ab] and [xy] into [abxy]

Mat's Mug

that's pretty cool

mjolka

you earned the badge bit-wizard

Mat's Mug

hehe not yet

I need to play a.. bit

mjolka

groans

Dan Lyons

There are some more toys then: ^ and ~

xor and negation

or maybe inversion is a better way of putting it than negation

shrug it flips bits

Mat's Mug

12:24 AM

0101^ == 1010?

(opens up sandbox console app)

Dan Lyons

^ is for xor, so 0101 ^ 1100 == 1001

mjolka

(╯°□°）╯︵ 0101

2

Dan Lyons

~ is for negation, so ~0101 == 1010

Mat's Mug

ah

my gosh, haven't done that level of binary math since ...2000 or so

Phrancis

@Mat'sMug I noticed mysql is not in your favorite tags ;)

Mat's Mug

12:27 AM

@Phrancis I shall fix that

Dan Lyons

I don't use bitwise operations that often anymore. I get a nostalgia buzz when I can figure out how to inject it into something I'm doing, though

2

Mat's Mug

@DanLyons some 15 years ago I was able to make a bitmap transparent with a B&W mask and some XOR magic. I would totally fail doing that today. well I think I would.

+250 anyone? ends in 14 hours:

7

Q: Mobile touch menu

Unfortunately, the code in the original version of this question doesn't work, so I will rewrite this question. Please don't review this code until I have fixed it. See also this answer on Meta.

html css mobile

oh WTH

Dan Lyons

now, I think you can just tell the appropriate wpf and winforms controls what color to use for transparency, so as long as the bitmap has a solid background color, it's already done for you

Mat's Mug

yeah

Jamal

@Mat'sMug He still hasn't responded to my super-ping. It appears that the code in the previous revision was reviewed, so it may just have to be rolled back after the bounty ends.

Mat's Mug

12:33 AM

@Jamal will the 250 be refunded?

Jamal

It can be, if he wants. Mods are not obligated to refund bounties.

mjolka

@Mat'sMug referencesource.microsoft.com/#mscorlib/system/int64.cs#83 well... that's not what i expected

Mat's Mug

    public override int GetHashCode() {
        return (unchecked((int)((long)m_value)) ^ (int)(m_value >> 32));
    }

lol

mjolka

so i just gave a very round-about way of writing _numerator ^ _denominator

Mat's Mug

I like the Int32 implementation for GetHashCode:

    public override int GetHashCode() {
        return m_value;
    }

Phrancis

12:47 AM

@Mat'sMug Do let me know if you'd like for me to "translate" (downgrade?) your SQL Server example code into MySQL

Mat's Mug

@Phrancis yeah, I'm ...playing with some hash codes right now, you're right I should be working on that!

1/3 (float) hashcode: 1051372203
1/3 (fraction) hashcode: 1051372203
11/33 (fraction) hashcode: 1051372203

@mjolka indeed, both ways return... a hash code of...2

(for {1/3} Fraction)

and now I'm confused

Phrancis

What is a hash code?

Mat's Mug

> A hash code is a numeric value that is used to insert and identify an object in a hash-based collection such as the Dictionary<TKey, TValue> class, the Hashtable class, or a type derived from the DictionaryBase class.

mjolka

@Phrancis ericlippert.com/2011/02/28/guidelines-and-rules-for-gethashcode

Mat's Mug

hash != hasch, you can't smoke a hash code :/

2

Phrancis

1:00 AM

So... this brings the obligatory follow-up question what is hash? lol

Dagg Nabbit

<.<

Jamal

Wow! This question wasn't closed back in '11, and 200 finally found it and closed it.

Mat's Mug

Why bother commenting?

where were the modz back then!

Jamal

I didn't have to, but the closure doesn't notify the OP. I was tempted to delete anyway since the actual source code could be anywhere in there. I think the 15 rep would be lost, but the upvote rep will be retained.

Mat's Mug

Good call

Phrancis

1:10 AM

So hashing is essentially breaking out a large list/table of values of one kind or another into a bunch of much smaller table... and the hash code acts as a sort of reference key like a PK of sort... am I anywhere near?

Or completely wrong? (more likely)

Dagg Nabbit

@Phrancis hashing is breaking a big thing down into a small and theoretically unique thing

Yuushi

not so much unique, as there's obviously never going to be a bijection between a set of a larger cardinality and a set of a (generally much smaller) cardinality </mathematician>

Dagg Nabbit

that's why i said "theoretically" ... i meant something like "ideally"

@Phrancis check this out - en.wikipedia.org/wiki/Checksum

Yuushi

generally as long as it's randomly, uniformally distributed across the possible state space, you're good

mjolka

@Yuushi you didn't do maths at unimelb or anu, did you?

Yuushi

1:15 AM

that being said, coming up with good hash functions is really, really hard

@mjolka Nah, at Adelaide uni. But I do have a friend that went to ANU and did math

mjolka

ah, i did maths at anu/unimelb and was wondering if we'd met :)

Mat's Mug

So hash codes and equality are related; if two objects have the same hash code, they're equivalent. Hence if you override GetHashCode, you have to override Equals, or you'll run into problems. The kind that makes you say wtf-is-this-shit when you discover that the bug was because the developer implemented Equals but not GetHashCode, or vice-versa ;)

Jamal

@Yuushi Your latest answer reminds me that I should be exploring the STL further. I haven't known about std::inner_product...

Yuushi

@Jamal It sits in <numeric>, which I think 99.9% of C++ programmers forget about

mjolka

@Yuushi pure or applied?

Yuushi

1:16 AM

@mjolka What years were you there?

@mjolka graduated with honours in Applied, but I did a number of pure courses as well

mjolka

anu 2004-2007, unimelb 2008, 2010-2011

Yuushi

hrm, you may have had some classes with a friend of mine then

Mat's Mug

(bows)

Yuushi

you would have been there at a similar time

Jamal

@Yuushi Ah, I see. By the way, have you seen my rags-to-riches question?

Yuushi

1:17 AM

@Jamal Nope, not yet. I'll take a look

eh, Morwenn already got to it, I probably won't have much to add :)

Jamal

Okay. Maybe Loki or someone else will find something. :-) I am still proud of myself for using inheritance for a change. Having a list of getters and setters is just gross.

Yuushi

hrm, ok, I can see one thing he missed

Mat's Mug

should I remove this comment?

@VDohnal you're reading it wrong. 1 tournaments -> * tournament matches; 1 tournament match -> * results. A TournamentMatchResult can only belong to one TournamentMatch, which can only belong to one Tournament. The only associations in that diagram, are one-to-many.... — Mat's Mug 3 hours ago

mjolka

@Mat'sMug "if two objects have the same hash code, they're equivalent" ?

Mat's Mug

as far as having a hash code goes, yeah... no?

objects that are equal should have the same hash code.

mjolka

1:29 AM

i agree with the second statement

Yuushi

@Jamal Ok, added another small point

Mat's Mug

whatever the equality rule is

Yuushi

technically, hashing defines an equivalence relation

not equality

Jamal

:-)
I don't think my compiler has default destructors, unfortunately.

Yuushi

@Jamal Just replace =default with { } then :_)

Mat's Mug

1:31 AM

@Yuushi that

Jamal

@Yuushi Ah yes, of course.

mjolka

@Mat'sMug ah, i read it as x.GetHashCode() == y.GetHashCode() => x == y. i see what you meant now

Mat's Mug

yeah; two objects that are equivalent should also be equal, and two objects that are equal are obviously equivalent. but equality and equivalence are two things.

ckuhn203

Ummm I don't know. I'm more of a math geek and I'd say that's a false statement.

Equivalence means two things can be mapped onto each other.

Equality means they are practically identical.

Not sure how that applies to hashing though.

Mat's Mug

(4/2).Equals(2) == true; (4/2).GetHashCode().Equals((2).GetHashCode()) == true

        public class Foo { }

        static void Main(string[] args)
        {
            var foo = new Foo();
            var bar = new Foo();
            Console.WriteLine(foo.GetHashCode().Equals(bar.GetHashCode()));
            Console.ReadLine();
        }

outputs false because Foo doesn't override GetHashCode, and object.GetHashCode() returns a value that represents the reference held by the object instance, so unless foo and bar were the same object, GetHashCode() returns a different value.

ckuhn203

1:54 AM

Ahhh. Yes. They are equivalent, but unequal.

Foo can be mapped onto bar, but it is not bar.

mjolka

when we say that two things are equivalent, there's an implicit equivalence relationship (~) that we're talking about. as @Yuushi said, GetHashCode defines an equivalence relationship between objects via x ~ y <=> x.GetHashCode() == y.GetHashCode()

but it is not true that because two objects are equivalent under this equivalence relationship, that they should be equal

however if x == y then a properly defined GetHashCode will satisfy x.GetHashCode() == y.GetHashCode()

Phrancis

2:12 AM

Interesting discussion going on here!

mjolka

2:23 AM

randomly failing unit tests -_- this is gonna be a long day

Captain Obvious

-2

Q: Embed watermark image to another image

can help me solve how to embed watermark image to image? But the watermark image to image is invisible. Hope can provide code.

android

Dagg Nabbit

3

Q: Do AMD loaders need a way to initiate module resolution other than "define?"

In a discussion about a tangentially related aspect of a minimal AMD loader I'm working on, James Burke wrote: There should to be some way to kick off the resolution of modules, besides just define(). define() calls by themselves should just register the existence of a module definition, but ...

javascript amd loader

^ any idea why this would get downvoted

ckuhn203

2:41 AM

For whatever reason, people have come to expect SO questions to always contain code. It's a debugging service these days.

Mat's Mug

downvoter's way of saying "I think that one belongs on Programmers"?

ckuhn203

That^

Captain Obvious

0

Q: Safely network reconnection (netty based)

NettyConnectionManager.scala: class NettyConnectionManager(val config : NettyConfig) extends ConnectionManager { @volatile private var connection: Option[Connected] = None def get() = { if(isConnected) { connection } else { synchronized { if(connected) { ...

java scala thread-safety

Dagg Nabbit

@Mat'sMug it does belong on Programmers, but the people I actually hoped to get an answer from (like the guy who answered) do no frequent that site, so posting there would probably be useless

also double-checked the SO FAQ to make sure it was not off-topic there; it's not afaict

Mat's Mug

bah, the upvotes largely buy back the downvote ;)

Dagg Nabbit

2:46 AM

lol, that's true... I have plenty of rep there anyway, just was confused by the meaning of the dv

Mat's Mug

3:06 AM

@Phrancis I got the t-sql

use Sandbox;

declare @result table (SizeIndex int, Units int);

declare @input varchar(80);
set @input = '                       1   2   2   4       4       2   2   1                    ';

declare @fieldCount int = 20;
declare @fieldLength int = 4;

declare @index int = 0;
declare @fieldValue varchar(4);

while(@index < (@fieldCount))
begin

	set @fieldValue = substring(@input, @index * @fieldLength, @fieldLength)
	if (isnumeric(@fieldValue) != 0)
	begin
		insert into @result
		select @index, cast(ltrim(@fieldValue) as int);

ckuhn203

3:21 AM

I feel really bad for anyone trying to write anything in LibreOffice Basic. I tried once. For a few hours. Much cursing was done that day.

1

Q: How do I make vba code compatible with libre office

I have recently migrated to pclinuxos from windows and seem to like it. The only problem I am facing is that libreoffice, the default spreadsheet package is not compatible with excel macros. Below is the vba code I have: Option VBASupport Sub DeleteToLeft() Selection.SpecialCells(xlBlanks)....

excel vba openoffice.org libreoffice

Ohhhh. Here's a good one. Some one is having trouble installing a vb6 app on win 7...

-4

Q: How to instal visual basic 6 softwares on Windows 7?

I was a Visual basic 6 programmer 2 years ago, and now I need to run my software that made with visual basic 6 on windows 7 But when I install the program on windows 7 windows can't open and run my program. How to run it on windows seven? Why windows seven can't run it?

windows visual-studio vba windows-7 vb6

Mat's Mug

3:40 AM

@ckuhn203 I almost answered "rewrite it in vb.net, import the Microsoft.VisualBasic namespace"...

@ckuhn203 when the first thing you see is Option VBASupport, you know you're in for a ride

2

ckuhn203

Lol. @Mat'sMug. Yeah... A bumpy one.

I just go to SO when I feel like down voting a ton of questions. Then I see something that makes me go "You poor soul. I'm so sorry."

3

(Libreoffice guy, not VB6 guy)

Mat's Mug

4:03 AM

0

Q: Put it in a bucket

You're running a jeans company. Your system is collecting detailed orders' data, but it's a bit archaic and it's storing the number of units ordered per size in a delimited string with 20 "fields", each taking up 4 characters. You want to normalize this data to make it easier to eventually ana...

optimization sql parsing t-sql

and TTGTB - 'night @all!

@Phrancis ^^^ the version I put in chat is wrong, use the one here instead! -- I really have no idea how mysql could do that.

Captain Obvious

1

Q: Put it in a bucket

You're running a jeans company. Your system is collecting detailed orders' data, but it's a bit archaic and it's storing the number of units ordered per size in a delimited string with 20 "fields", each taking up 4 characters. You want to normalize this data to make it easier to eventually ana...

optimization sql parsing t-sql

Captain Obvious

4:28 AM

0

Q: Mutation to Lists; Values not mutating correctly

Purpose of code is as follows: My code is as follows: def align(points, max_diff): x_points = (map(lambda i: i[0], points)) x_avg = sum(x_points)/len(x_points) x_outer_bound = (x_avg+max_diff) x_inner_bound = (x_avg-max_diff) y_points = (map(lambda i: i[1], points)) y_avg = sum(y_points)/le...

python loop

Phrancis

4:45 AM

@Mat'sMug with difficulty :)

WTH is up with the spaces?

In @input etc?

Oh I think I get it. Empty spaces where there are no orders for said size

Man that is archaic

Captain Obvious

5:08 AM

0

Q: Strategy Game in Javascript with Three.JS

I've been playing around with porting a simple strategy game over to Javascript, the idea being to run it in a browser for testing. I've done some simple Javascript code in the past, but this is my first model/view setup. I'd love to get feedback on following Javascript best practices and avoid...

javascript html game mvc

chillworld

morning @all

Phrancis

Hello, @chillworld

chillworld

hey @Phrancis still awake?

Phrancis

I suppose you could call it that :)

insomnia

Dagg Nabbit

> You've earned the "Enlightened" badge (First to answer and accepted with score of 10 or more) for "FizzBuzz in Commodore Basic".

Code Review: the site where the questions, programming languages used, points, and badges don't matter.

Yuushi

5:25 AM

sounds like a certain TV show...

chillworld

I think @Phrancis is atm Enlightened :)

but gratz @DaggNabbit

Phrancis

@chillworld nothing enlightening like writing MySQL lol.

Dagg Nabbit

thanks @chillworld :)

@Phrancis is an outspoken necromancer

Apparently I am an enlightened enthusiast outspoken necromancer yearling with a good answer

chillworld

/D

I'm almost at the enthusiast badge

ow sorry almost fanatic badge

Dagg Nabbit

5:41 AM

how many days is fanatic?

chillworld

100

Dagg Nabbit

gold badges seem ridiculously hard to get here

chillworld

the fanatic still goes

that's completly in your hand

Dagg Nabbit

i could just set up a bot to ensure fanatic

chillworld

tss, 1 min work

If I'm not home for whole day, I do it quick with cellphone

Dagg Nabbit

5:49 AM

same with electorate and steward probably

chillworld

electorate we have to wait upon the event

Dagg Nabbit

i think electorate is just for voting on stuff

chillworld

oh lol

indeed

Phrancis

@DaggNabbit Re: gold badges, it seems it's upvotes that are difficult to get lol.

Dagg Nabbit

@Phrancis especially if you're dealing with anything that isn't Java

Phrancis

5:51 AM

^^ that

chillworld

I know 1 badge what will be hard to get here

unsung hero (and yet 1 time awarded)

-2

A: Union-set for ordered representation

Your implementation looks good. =)

-2 voted andyet accepted

Dagg Nabbit

nice

chillworld

at least the downvoters may leave a comment

Dagg Nabbit

someone even got a Reversal - codereview.stackexchange.com/questions/40146/…

Reversal shouldn't be hard to get on sites like SO, where the downvotes mean "nooo you're doing it wrong" and the upvotes mean "yes, do it like this instead"

but here it seems like you get upvotes for doing it wrong =/

chillworld

it's hard to get that reversal

I do hate the DBA team (or they hate me)

admin user has lost his rights :s

and gues the user do call admin :D

now break :)

Dagg Nabbit

6:00 AM

ahahah that sucks

chillworld

brb in 30 min

skiwi

Monking

Phrancis

6:14 AM

Hi @skiwi

chillworld

moning @skiwi

@DaggNabbit time to write (again) the sql script to give admin user admin rights

Jeroen Vannevel

Good morning

chillworld

6:31 AM

morning @JeroenVannevel

Dagg Nabbit

wonder why some of my github repos say "0 contributors"

Phrancis

This SQL end statement always makes me feel sad face: );

chillworld

@DaggNabbit cause github doesn't see you as contributor? :p

Dagg Nabbit

@chillworld but with other people's repos there's always at least one...

chillworld

normally the creater is a contributor

Dagg Nabbit

6:43 AM

hmm maybe it's because my local git settings have a phony email address

1752

Q: Why does HTML think “chucknorris” is a color?

How come certain random strings produce various colors when entered as background colors in HTML? For example: <body bgcolor="chucknorris"> test </body> ...produces a document with a red background across all browsers and platforms. Here is a Fiddle. Interestingly, while chucknorri produces a...

html background-color

Originally, it wasn't going to be part of HTML 1.1, but it inserted itself into the specifications after the first time Chuck Norris used a browser. The color is said to be modeled after the color of his beard. Fact: setting your background color to chucknorris will crash IE6, IE7, IE8, IE9, and versions of IE yet to be invented. It will also crash your computer and roundhouse kick you in the face. — slothario Feb 6 '13 at 0:35

Phrancis

YES I found the stupid syntax error that's been bugging me for 2 days.

skiwi

Does anyone know if this regex is correct?

private static final Pattern IBAN_NUMBER_PATTERN = Pattern.compile("^[a-zA-Z]{2}\\d{2}[a-zA-Z\\d]{11}$");

Not sure especially the [a-zA-Z\\d] part

Dagg Nabbit

@skiwi don't IBAN numbers look different in different countries

skiwi

@DaggNabbit True, there's a second validation layer after this

So far I've found they always start with 2 letters (country), 2 digits (checksum) and must be minimal 15 characters

(I can't afford to validate all things that look like text in my OCR output)

Dagg Nabbit

6:59 AM

I've seen IBAN validators that are like 200 lines long =/

skiwi

You mean... a regex of 200 lines?

Dagg Nabbit

no, a big switch with country codes

they usually don't even bother with regex

skiwi

I can imagine

Ultimately it'll be checked against a database with real entries anyway

But cannot spam that web service/database

Vogel612

get yourself a few examples and have them as unit-test cases then

monking btw

Dagg Nabbit

@skiwi [a-zA-Z] is weird, just do [a-z] and make it case-insensitive

with /i

skiwi

7:03 AM

That's a good point there

Dagg Nabbit

and yeah i'm pretty sure you can't do [\d]

skiwi

Need to figur eout how that works with java

Dagg Nabbit

no i lied

[\d] works

Some things don't work in character groups, like [.] is a literal dot

skiwi

[a-z0-9] is actually more clear though here

Yeah I need to build unit tests for this some time... soon

btw, from now on you really need to remember to incrementally build and test if you are upgrading to a higher Java version

Say you upgrade from Java 7 to Java 9 in one go

In Java 7 _ is a valid identifier for a parameter

In Java 8 it became deprecated and triggers warnings

In Java 9 it may get a different meaning

Single upgrade from Java 7 to Java 9 = have fun

Vogel612

so java 9 announced??

Dagg Nabbit

7:09 AM

there's a Java 9 already?

skiwi

No of course there's no Java 9 yet :P They're not that quick.

But Java 8 has reclaimed the _ back as invalid identifier

Vogel612

skiwi don't make us crazy, just because you read some Proposal....

skiwi

And some future new version will use it for a new construct

Dagg Nabbit

I hope some version of JavaScript make $ an invalid identifier just to stir things up

4

Phrancis

^^ or PHP lol. Those people would freak out.

skiwi

7:18 AM

Something changed in my IBAN verification for sure

I should've had unit tests already up.

skiwi

7:29 AM

A start of the day where everything works, is a good start of the day.

Vogel612

8:08 AM

@skiwi lucky you..

well I got my selectCheckboxMenu to work now..

sooo.

Morwenn

9:25 AM

The last message was posted 1 hour ago.

Nobody

1 hour later…

3

Morwenn

Nobody's answering.

skiwi

Nobody's here!

CodeX

Monking!

I just Bobby Tabled myself... ;DROP TABLE wcx_articles :/

skiwi

This behaviour so makes no sense sometimes... I see I'm logged out on CR, I go to login page, and then it detects that I'm logged in and redirects me!

CodeX

9:29 AM

Are you logged in somewhere else?

Morwenn

One month later...