Become a fan of Slashdot on Facebook


Forgot your password?
Check out the new SourceForge HTML5 internet speed test! No Flash necessary and runs on all devices. ×

Comment Re:The road to Trondheim (Score 3, Informative) 84

The article is misleading in suggesting that driving from Kristiansand to Trondheim currently takes about 20 hours. It does that if you roughly follow the coastline. However, there is already a much faster route going through Oslo.

Where floating tunnels may make sense is for shorter trips - for example Bergen to Ålesund.


Ask Slashdot: Cheapest Functional Computer For Students? 508

An anonymous reader writes: I've started a second career, teaching English at a High School in a middle class area. While the large majority of students have a computer and internet access at home, about 10-15% do not. I assign papers that must be typed, I have papers turned in online, and I plan to freely refer to texts, videos, and other resources that are available online. This gives an extra disadvantage to students that may be from the poorer end of the strata, and also means extra inefficiency for me, as I have to make allowances for students who don't have a computer available at home.

Right now, I have to tell them to either use school computers during the day, or to pick up a $170 laptop (more than enough — I administer the class using such a laptop). However, I was surprised at the lack of a super-cheap option for students. I'd love to see something for $20 that any student could afford easily, or perhaps I could just gift to a few students. I feel like something in this price range could be sufficiently powerful for basic word processing, youtube videos, and internet searches (internet access is a separate issue). But looking over my options I see:

1) The very cheapest Chromebooks are also in the $170 range.
2) Android Sticks have been around for a while, and do cost in the $20 range, but don't seem to have matured into a generally usable technology. Surprisingly, there doesn't seem to be a community effort to easily turn these Android sticks into Ubuntu/Mint sticks.
3) Students can't be assumed to have the technical know-how to fix up a Salvation Army computer (I wouldn't mind helping out a bit, but I don't want to turn into tech support)
4) A Raspberry Pi costs $70 once you include a case/power supply/etc, and students would receive a big bag of parts.
5) Cheap Windows Tablets have glitches, and don't have an HDMI out.
6) There isn't a good solution to using a cell phone as a desktop computer.

Are any of my assumptions wrong? Are there any other options I'm not considering?

Comment Re: ..that runs on the Java platform. (Score 1) 62

Thanks. Kawa has what one might call "optimistic typing": The compiler calculates the type of an expression, and compares it with the type required by context. It only complains if this intsection is empty. In contrast, in traditional strict typing the compiler requires that expression type be a sub-type of the required type (unless there is an explicit cast). I've thought about adding an option to Kawa (it wouldn't be the default) to implement strict (sub-type) typing. However, that would require various changes and some thought to make palatable.

Comment Re:How does it compare to Clojure? (Score 2) 62

Ask Rich Hickey that: Kawa (1996) is 11 years older than Clojure (2007).

The linked LWN article meantions some reasons: Among them that Kawa is much faster than closure (both execution speed and start-up speed). Plus some might like that Kawa is mostly-compatible with a pre-existing independently-specified language.

Comment Re:Traditional (Score 3, Insightful) 62

"Something that I find strange is how fast kawa seems to be [even] in the repl." Note that Kawa does a full compilation (to bytecode), with all the optimizations, even in the repl. (Of course it only optimized one line/command at a time in that case.) The downside is that Kawa is a little fragile if you redefine things in the repl; hence I advise using the --no-inline option for the repl. It's on the list of things to work on when we get a chance.

Comment Re:Traditional (Score 2) 62

Neither Java or Kawa are "traditional compiled language" in the same sense as C or C++. However, Java as a language (rather than as an implementation technology) is much closer in style to C++ than (say) Python or Ruby. Java has lexical scoping, static name resolution, ahead-of-time compilation (albeit to bytecode), does lots of compile-time error checking. In the current environment, Java (and Scala) are considered closer to "traditional compiled language" than languages like Python or Ruby, which are considered "scripting languages". Of course there is no hard distinction between the two kinds (except marketing) - and Kawa aims at the strengths of both kinds.

Comment Re:kawa (Score 4, Informative) 62

The Kawa 0.1 interpreter from 1996 was written by Alex Milowski, who is indeed Polish-American.

I took it over in 1996, and re-wrote it as a compiler. At this point, I doubt any of Alex's code still exists. I'm Norwegian-American, and Kawa means nothing in Norwegian. Still, I saw no reason to change the name.

Submission + - Kawa 2.0 supports Scheme R7RS

Per Bothner writes: Kawa is a general-purpose Scheme-based programming language that runs on the Java platform. It combines the strengths of dynamic scripting languages (less boiler-plate, fast and easy start-up, a REPL, no required compilation step) with the strengths of traditional compiled languages (fast execution, static error detection, modularity, zero-overhead Java platform integration).

Version 2.0 was just released with many new features. Most notably is (almost) complete support for the latest Scheme specification, R7RS, which was ratified in late 2013. This LWN article contains a brief introduction to Kawa and why it is worth a look.
Data Storage

ZFS Hits an Important Milestone, Version 0.6.1 Released 99

sfcrazy writes "ZFS on Linux has reached what Brian Behlendorf calls an important milestone with the official 0.6.1 release. Version 0.6.1 not only brings the usual bug fixes but also introduces a new property called 'snapdev.' Brian explains, 'The snapdev property was introduced to control the visibility of zvol snapshot devices and may be set to either visible or hidden. When set to hidden, which is the default, zvol snapshot devices will not be created under /dev/. To gain access to these devices the property must be set to visible. This behavior is analogous to the existing snapdir property.'"

Comment Re:texinfo is good for writing documentation (Score 1) 173

Aside from the fact that it's Just Plain Horrid(TM) to read or write in source format, TexInfo suffers from the same problem that HTML does: No semantics.

You don't seem to know much about Texinfo. It is definitely very much about semantics - quite like DocBook. I agree DocBook takes the semantics thing slightly further than Texinfo - but it has big holes too: For example DocBook doesn't have a standard way to specify the structure of a command/function synopsis except for the C language.

The reason that DocBook is so "verbose" is that it actually indicates what things are.
One reason DocBook is so verbose is because it is XML, which by definition is verbose and human-unfriendly.

I've written plenty of documentation in both Texinfo and DocBook. They're both reasonable formats, but it is clear that DocBook is very tedious if you have to write it "by hand" rather than use a word-processor. Texinfo is much easier to both read and write, and it handles the "semantics" pretty well.

Comment texinfo is good for writing documentation (Score 2) 173

Texinfo is is a decent format for writing documentation in - nicer and less verbose than HTML or DocBook. You can generate either HTML or DocBook or XML from Texinfo, and then do a bunch of processing on it. For example the documentation for Kawa is written in texinfo, then makeinfo converts it to docbook, which is then converted to html. The result isn't splashy but (if I say so myself) fairly nice.

Slashdot Top Deals

"The only way I can lose this election is if I'm caught in bed with a dead girl or a live boy." -- Louisiana governor Edwin Edwards