jz391

2 months agodiscuss

I think many of us miss that feeling... For me, the level of complexity of the computers in my childhood (TRS-80, Spectrum) made them interesting but still possible to fully understand. I think we have lost that - modern hardware and software has complexity on a scale which makes it impossible to fully follow. After decades of computing, I only have a high-level understanding of many components of a typical PC. So for my son, any understanding of what's going will be difficult...

jz391

2 months agodiscuss

I do understand it takes effort to stop and re-accelerate, but isn't making effort (exercise) part of the purpose of cycling in the first place? My main objection is to cyclist failing to stop at pedestrian crossing lights: as a pedestrian, when I see a green light, I expect to cross without having to dodge moving vehicles on the road. I do check the the road to make sure that cars have stopped, but cyclists (who rarely stop at crossings, at least in London) are harder to see, as they are smaller and often obscured by the traffic.

jz391

2 months agodiscuss

Definitely agree with the sentiment (also a Speccy 48K guy), but at the risk of being pedantic, I think you're double-counting: "million times faster" is for one Spectrum, the "0.000625% price" is for a million...

jz391

2 months agodiscuss

Braces are substitution, so

  b{a/x}

means: expression b with variable x inside it replaced by expression a. So their beta-reduction line just says that if

  k = ... (λx.b) a ...

it can be reduced to

  k = ... c ...

where c is the expression b, but with all occurrences of variable x replaced by expression a.

I think Tk(x) denotes "the definition of variable k is expression x" and the square brackets are "k[x]" something like "in the context of definition k, value of expression x". So I suspect that

  a=Tk(x)
  a[y]

would be effectively

  (λk.y)x

But yes, not very clear on explaining the notation. Also seems to have some typos e.g. at the beginning have "x ∈ k, x, y" which looks to me should be "x ∋ k, x, y" (or of course "k, x, y ∈ x").

jz391

2 months agodiscuss

> I wouldn't call it "exceptionally nice"

I guess depends on your reference point :-) I recall in the beginning, python offering an easier/more readable alternative to Perl, which itself was a step up from awk/sed/sh script (for the tasks/uses GP mentions)

jz391

3 months agodiscuss

Reminds me of a commercial project I did for my old University department around 1994. The GUI was ambitious and written in Motif, which was a little buggy and leaked memory. So... I ended up catching any SEGVs, saving state, and restarting the process, with a short message in a popup telling the user to wait. Obviously not guaranteed, but surprisingly it mostly worked. With benefit of experience & hindsight, I should have just (considerably) simplified it: I had user-configurable dialogs creating widgets on the fly etc, none of which was really required.

jz391

3 months agodiscuss

The key issue is that Lisp's minimal uniform syntax has less variation to help with visual pattern matching, which we humans are good at (compared to richer syntax).

The meta-programming power of Lisp may be largely due to being homoiconic, although Dylan/Julia etc achieve similar without it. However Lisp's minimal syntax is not a prerequisite for homoiconicity: S-Plus/R has a more conventional syntax while retaining "code is a list" representation.

jz391

4 months agodiscuss

To extend your analogy: if the house is a listed building (UK concept; apparently US equivalent is listed in National Register of Historic Places), by law you cannot just tear it down. You need to do much more work to renovate what can be done without disturbing the original structure. This obviously costs much more and is generally done by different specialists, who have harder job and hence are better paid. So the question comes back to: what kind of work do you want to do...

jz391

4 months agodiscuss

And, of course, the next level of procrastination is to develop your own programming language, which you will use to write the engine to use in creating the game :-) Definitely hats off to Jon for pulling it off - he had a lot of focus and some previous experience - and it also helps to have re$ource$ from past successful games. For many of us, the lure of developing better tools, rather than the end product, proves to be too strong to resist. At least Jon stopped short of developing own OS :-)

jz391

6 months agodiscuss

True for many, but I actually have been acquiring some computing books I had enjoyed reading in my youth (e.g. Organick's Multics). Perhaps living permanently abroad strengthens nostalgia...

jz391

7 months agodiscuss

Interesting. The voice used for the pronunciation sound seems to be using the wrong language though (FYI using Firefox).

jz391

8 months agodiscuss

Absolutely. As an Electrical Engineer turned software guy, Ohm's/Kirchhoff's laws remain as valid and significant as when I was taught them 35 years ago. For software however, growth of hardware architectures/constraints made it possible to add much more functionality. My first UNIX experience was on PDP-11/44, where every process (and kernel) had access to an impressive maximum of 128K of RAM (if you figured out the flag to split address and data segments). This meant everything was simple and easy to follow: the UNIX permission model (user/group/other+suid/sgid) fit it well. ACLs/capabilities etc were reserved for VMS/Multics, with manuals spanning shelves.

Given hardware available to an average modern Linux box, it is hardly surprising that these bells and whistles were added - someone will find them useful in some scenarios and additional resource is negligible. It does however make understanding the whole beast much, much harder...

jz391

8 months agodiscuss

Indeed. Coming from UNIX tools (sed/awk/sh/grep/tr etc), perl had a lot of appeal and almost intuitive syntax - alternatives in the '80s being C, awk, or if you were unlucky, FORTRAN IV without string type :-). The benefit of having a single language with all of the functionality of these tools was amazing at the time and ability to use familiar syntax was a benefit. However expectations for programming languages grew somewhat since...

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