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Ask Slashdot: Is Pascal Underrated?

petermgreen Re:Modula-3 FTW! (470 comments)

but in practice what you have in c is more likely

double a = b/c

is that doing floating point division or floored division? you can't tell without going and searching for the defintion of b and c and if you want floating point division of two integer arguments (a perfectly reasonable thing to want to do in many situations) you have to start putting in typecasts. It gets even worse in dynamically typed languages that use derivatives of C syntax.

3 minutes ago

Ask Slashdot: Is Pascal Underrated?

petermgreen Re:Modula-3 FTW! (470 comments)

Unfortunately it seems it's owner has gone to the "charge locked in customers a shitload of money" strategy. That may be profitable in the short term but it's not going to win you many new customers when the alternatives are free. Theres a starter edition whose price is a bit more paletable but whose license terms are most certainly not.

Theres lazarus of course, not sure how that compares nowadays.

2 hours ago

Google Handed To FBI 3 Wikileaks Staffers' Emails, Digital Data

petermgreen Re:Under Search Warrant (187 comments)

And the lesson is if you care about privacy you should avoid storing your data with multinational companies because every nation in which the company operates is a nation that could potentially coerce the company into handing over your data..


Surface RT Devices Won't Get Windows 10

petermgreen Re:Translation: (157 comments)

RT has desktop mode.

AIUI the original plan was not to have it at all but they couldn't get office converted to metro in time so they included the desktop mode but crippled it by forbidding desktop apps other than the handful bundled with the OS (a cut down version of office, some of the built in windows tools).

The only reason I can see for crippling the desktop mode on the arm port was pushing developers to switch to metro.

Would windows on arm have succeeded if people could just recompile their software for it rather than having to redesign their software to fit within the constraints of metro and then on top of that pay a 30% appstore fee to MS? We will never know for sure but I strongly suspect it would have had a better chance than in the crippled state it was sold in.

3 days ago

User Plea Means EISA Support Not Removed From Linux

petermgreen Re:What about ISA? (188 comments)

From a software perspective what sets memory/IO mapped busses apart from each other is how the OS reads and/or sets their configuration, not what they are like on an electrical level. ISA was either manually configured or (later) used a hacked on plug and play mechanism. EISA had it's own configuration system.

4 days ago

Oracle Releases Massive Security Update

petermgreen Re:But Java... (79 comments)

Java protects against some of the common screwups that lead to security holes in C (and to a lesser extent C++) programs. It simply won't let you do things like read/write beyond the end/before the start of an array, perform an unprotected typecast between two object types or use memory that you have already freed. However there are many other classes of security hole it doesn't help with.

Java sees lots of security patches for a couple of reasons

1: Java provides sandboxing features intended to allow safe running of untrusted code. Unfortunately such sandboxes seem to be very difficult to get right (whether it's java applets, flash or javascript in browsers).
2: Java provides a massive standard library. It's virtually an OS within an OS and that means lots of code to be potentially vulnerable (especially in light of point 1)

5 days ago

Windows Server 2003 Reaches End of Life In July

petermgreen Re:So firewall it already (156 comments)

The tricky situation comes if you've built your application on top of windows network functionality rather than directly on top of TCP/IP. That can make it very difficult to lock things down with a firewall because the high risk ports and the ports your application relies on can be one and the same.

5 days ago

Is D an Underrated Programming Language?

petermgreen Re:The thing about new languages... (382 comments)

And then there is a the question of portability. There is a C compiler for virtually anything powerful enough to support a compiler. C++ rules out some of the smaller microcontrollers but is available virtually everywhere else. Sure the code may need some work to remove platform specific assumptions, deal with missing library functionality on very small targets or deal with compiler bugs but that is still likely to be much easier than a complete rewrite.

Any new language that is intended to be compiled to native code (either at compile time or at runtime by a JIT) has a massive uphill struggle to come close to the portability of C/C++. AIUI GDC only got proper support for arm linux very recently and is still missing proper support (e.g. the libphobos standard library) for many architectures.

Scripting languages have things a bit easier because they usually piggyback on the existing C/C++ compilers. So the developers for the most part only have to worry about OS portability, not CPU portability.

about a week ago

Google Pondering $1 Billion Investment In SpaceX's Satellite Internet

petermgreen Re:Needed! (100 comments)

Theres a couple of causes

One is something called interleaving, DSL uses forward error correction algorithms to provide resistance to noise/interference. However these algorithms fall apart if there are too many bit errors in a block. To reduce the chance of this happening in the face of interference spikes they interleave the blocks (such that a burst of interference has a small effect on multiple blocks rather than a large effect on one block) but this comes at a price in terms of latency. At least here in the UK some of the more techie ISPs will turn this off if asked.

The other is that your "first hop" can be considerablly longer than just the DSL line to the telephone exchange because your connection tunnels through the phone providers network to reach the ISP. If you are on a small ISP in the UK your packets will most likely go to london before they hit a visible IP router. Larger providers are likely to hit the IP network sooner but it may still be a considerable distance from where you live.

about a week ago

Insurance Company Dongles Don't Offer Much Assurance Against Hacking

petermgreen Re:Who would ride with these dongles anyway? (199 comments)

Who would ride with these dongles anyway?

Desperate teenagers who are priced out from getting insurance any other way!

about a week ago

NetHack Development Team Polls Community For Advice On Unicode

petermgreen Re: Short of memory? (165 comments)

Is there any easy way to tell where one grapheme cluster ends, and another begins? With UTF-8, it's easy to count the bits to see where one codepoint begins and ends, I hope there is something equally simple for grapheme clusters. Or perhaps it's all complicated and is different for each language?

As I understand it it comes down to table lookups. The details of full unicode support are unfortunately not trivial and theres a reason libraries like ICU are as big as they are.

Also, if I do accidentally split a grapheme cluster in two (while respecting codepoint boundaries), what will happen? If I attempt to display the two strings, can I expect a sensible result, or will the result be garbage?

As I understand it normally the base character is first and then things added to it follow.

So if you cut the end off a string and cut in the middle of a cluster then the last character may be missing some bits but the string is likely to be otherwise OK.

If you cut the start off a string and cut in the middle of a cluster things get messier. You then have combining characters at the start of the string with nothing to combine with. If you just ask a display library to display it then it's going to be down to the display library what happens but I expect the combiners will either be not displayed at all or displayed with no base. If you add the cut string to the end of another string then the combiners will combine with whatever was at the end of the string you combined it with.

All in all you will probablly end up with something "ugly but usable".

about a week ago

Windows 10: Can Microsoft Get It Right This Time?

petermgreen Re:It doesn't have to get it right (489 comments)

I find this quit interesting as Win7 has officially gone EOL [slashdot.org].

No it's moved from mainstream support to extended support. Still nearly 5 years left before EOL.

You don't get any free support incidents with OEM copies anyway and most crippling bugs will have been fixed or worked around by now. So for most users the transition from mainstream support to extended support isn't really a massive deal.

about a week ago

SpaceX Landing Attempt Video Released

petermgreen Re:Curiously familiar (248 comments)

My understanding was that the long term plan was to return most first stages directly to a landing site on land. When they don't have enough fuel to do that they would land it on the barge then partially refuel the stage and fly it back to base. Of course this relies on them managing to convince the powers that be that it's safe to land falcon 9 first stages on land.

about two weeks ago

SpaceX Landing Attempt Video Released

petermgreen Re:Wait a minute (248 comments)

I would imagine that anything that goes to mars will either have separate ascent and descent stages or some kind of CO2+energy->fuel conversion setup on the mars surface.

AIUI the "red dragon" sample return proposal from spacex had an unmanned dragon capsule landing and then a much smaller ascent craft to take the sample to mars orbit (where presumablly it would dock with a craft for return to earth).

about two weeks ago

PC Shipments Are Slowly Recovering

petermgreen Re:Shoddy journalism (130 comments)

Microsoft isn't sharing the pain because they didn't drop their per unit monpoly winnings... for now.

MS recently introduced something called "Windows 8.1 with Bing". Basically they are giving away windows free for low end laptops and tablets on the condition that the PC vendor doesn't change the default search engine.

about two weeks ago

UK Computing Teachers Concerned That Pupils Know More Than Them

petermgreen Re:Any experienced teacher already deals with this (388 comments)

Until very recently computer education in the UK was heavilly focussed on "ICT" which to a large extent ammounted to "pushing buttons in MS office". There was an attidude that permated the computing world (both inside and outside schools) that "you don't need to understand how it works" or "it's too complex for you to understand". Microcomputers that started up at a basic prompt where replaced with PCs were the ability to program was hidden if it was there at all. Systems that curious kids could fiddle with were replaced by systems locked down by network admins.

The result of this attidude persisting for a long time (a couple of decades afaict) was a decline in the number and skill of people applying to university for computing related programs. This decline got the attention of people in high places and there is currently a push to move away from "ICT" to a computing syllabus that actually includes programming and learning about the fundamentals of computers.


Hence teachers pushed into teaching an area in which they have little knowlege and confidence. Combine that with the availability of material on the internet and through various other outside-school sources and it's not going to be difficult for the top pupils to legitimately overtake the teachers and the mediocre pupils to give the impression that they know more than the teacher.

about two weeks ago

Microsoft Ends Mainstream Support For Windows 7

petermgreen Re:Nostalgic for Windows 7? (639 comments)

MS has one of the better support lifecycle policies in the desktop OS market. Mainstream support lasts 5 years from release or 2 from the release of the successor whichever is longer. Then extended support lasts another 5 years or 2 from the release of the second successor, again whichever is longer.

The problems are that they sometimes turn out turds, often vendors of other software can sometimes be very slow on getting it to work properly with the new OS and often people are too cheap to upgrade their other software even when a compatible version is release. The overall impact of this is that people kept commisioning new windows XP machines right through the time when windows vista was the current version and into the time when windows 7 was the current version until they were pushed to windows 7 by a combination of security worries from the end of extended support and hardware vendors dropping driver support.

I would expect the same to happen with windows 7. Lots of people/companies will stick with windows 7 until windows 10 has been released and got through it's teething problems, then they will have an upgrade panic while windows 7 is in the last couple of years of extended support.

about two weeks ago

NetHack Development Team Polls Community For Advice On Unicode

petermgreen Re:UTF-32 would save memory in some cases (165 comments)

when operating with the constraint that there is a single unicode code point per data structure/item/tile/object/whatever.

Fixed that for you.

So you'd support rare chinese characters but exclude unusual letter/diacritic combinations.

about two weeks ago

NetHack Development Team Polls Community For Advice On Unicode

petermgreen Re: Short of memory? (165 comments)

What does "character" mean?

Something represented by one unicode codepoint? (making your statement a tautology)
Grapheme cluster? (what most users would consider a character)
A position in the character grid of a console?

Which brings us to the real question. to what extent do you want to support unicode? do you care about

* Grapheme clusters that take multiple code points to represent? (letters with multiple diacritics, unusual letter/diacritic combinations etc)
* Right to left languages? (hebrew, arabic etc)
* Languages where chracters merge together such that computer output looks more like handwriting than type? (see above)
* Languages where "fixed" width fonts use two different widths giving "single width" and "double width" characters? (chineese, japanese, korean)
* Characters outside of the basic multilingual plane? (rare Chinese characters, dead languages, made up languages, rare mathematical symbols)

Once you have worked though that design decision it will help you make others. What you find is that "length in unicode code points" and "unicode code point n" really aren't much more useful than "length in utf-k code units" and "utf-k code point n". Either is fine for sanity checking string length or iterating through a string looking for delimiter. Neither is much use for anything more than unless you are doing a very limited implementation.

UTF-32 seems enticing initially but turns out to be fairly pointless, by the time you get to caring about non-BMP characters you are probably also going to be caring about combining characters etc and it will massively increase the size of the vast majority of text.

UTF-8 vs UTF-16 is something of a tossup. UTF-16 lets you get away with treating each unit of the string as one "character" much longer which may be considered either a blessing (because you don't care about the cases where it doesn't work) or a curse (because you realise your assumptions were wrong much later after basing much more code on them). UTF-8 is smaller for text with lots of latin chracters, UTF-16 is smaller for text with lots of CJK characters. UTF-8 is the usual choice on *nix systems and internet protocols. UTF-16 is the encoding chosen by windows and Java.

about two weeks ago

Ask Slashdot: Sounds We Don't Hear Any More?

petermgreen Re:about fax (790 comments)

Theres also providers who will provide you with a fax number that forwards to email.

about two weeks ago


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