dkfellows

6 ms·

1.
by dkfellows 3y ago
You need tools adequate to the task, but the task isn't necessarily what other people think it is. In this case, I'd bet the tasks are to learn what's going on inside a database and become better at programming in Python, n
2.
by dkfellows 3y ago
Almost all quoting for non-trivial cases comes down to the [list] command. It does the Right Thing, especially in the critical cases where you're generating a command to call later. Pretty much everything else is either much simpler to
3.
by dkfellows 3y ago
The main issue with supporting those IDEs is that the Language Server Protocol is vast and really quite complicated. More than a weekend's work to go to doing the interesting bits so life gets in the way... The IDE tools for Tcl have t
4.
by dkfellows 3y ago
Python has nothing at all like safe interpreters (I've looked). You just can't prevent things from leaking, it isn't designed for it at all. You can do a half-hearted approach by specifying the globals dictionary to eval(), b
5.
by dkfellows 3y ago
Well, there are classes and objects in there now. They're designed for modelling pretty heavyweight entities like widgets instead of lightweight things like linked lists. It was a fun OO system to write. It's much more dynamic tha
6.
by dkfellows 3y ago
Technically, all values are considered subtypes of strings, but the notion of types is quite different to those of many other languages. In particular, Tcl's types do not describe the memory storage model of their values. (They're
7.
by dkfellows 4y ago
Tcl uses a memory model internally where each piece of memory belongs strictly to the thread that allocated it, with this enforced in lots of places. There are a few loopholes past it (for process-wide concepts such as the current working d
8.
by dkfellows 6y ago
Technically, Tcl's internal type system is that all other value types are subtypes of string, universally serializable to string, and will correctly round-trip through string. But it also means that you can type-pun stuff if you want;
9.
by dkfellows 8y ago
That's an excellent question! It's not at all like IP. The basic message size is (IIRC) 64 or 96 bits, comprising a system control word, an application header word, and an optional payload word. The application header word descr
10.
by dkfellows 8y ago
It's basically very different in approach to many modern computers. The cores are slow and low-powered, but the interconnect is very fast for routing small packets to multiple destinations, which means that computational tasks that wou
11.
by dkfellows 8y ago
It really depends on whether you include the memory in that count, as memory uses masses of transistors without being very interesting as most of those transistors spend their time just sitting there in a stable state. It's the transis
12.
by dkfellows 8y ago
There isn't a plan to do the whole human brain, and doing so would require both at least two further generations of hardware and likely building a new facility for deploying it in. If someone's got a spare billion, and a decade or
13.
by dkfellows 8y ago
> Science journalism is generally just awful. Not just science journalism. I've yet to see a journalist get a story 100% right where I knew the facts personally ahead of time. If you're lucky, they've just garbled people&#
14.
by dkfellows 8y ago
It theoretically has 1036800 processors. It doesn't actually have that many because core-level manufacturing yields aren't 100%. The software architecture is designed to be resilient to this.
15.
by dkfellows 8y ago
The million was a figure chosen to be eye-catching to funders and to force the initial design team to address scalability from the beginning, according to Steve Furber. So yes, it's a bit arbitrary. The actual figure is (for technical
16.
by dkfellows 8y ago
SpiNNaker is particularly for studying neural structure, especially on the scale from small groups of neurons up to brain structures of a few million, on timespans of a few seconds to a few hours at simulation timesteps on the size order of
17.
by dkfellows 8y ago
The unit cost of a chip isn't too much. The price of doing the design and creating the masks for the silicon OTOH...
18.
by dkfellows 8y ago
> Specifically, how will you prevent SpiNNaker from going down the same path as the Connection Machine - (stops doing AI stuff because, say, geneticists want to use it for protein sequencing)? I'm on the team. I can say that we&#x27
19.
by dkfellows 8y ago
The next generation will have single precision hardware floats, but that's still at the prototype stage (with little bits of the processor running on a monster FPGA in the lab). The key however is that SpiNNaker is a MIMD system (the c
20.
by dkfellows 8y ago
The processor cores in SpiNNaker run at 200MHz (yes, this is slow!), and can usually issue one instruction per CPU cycle (that's quite nice). However, the trick to getting lots of neurons in is in keeping the number of CPU cycles per
21.
by dkfellows 8y ago
Our press office are definitely a law unto themselves, but the analogy was drawn in the event. It's also inaccurate, as it doesn't count the extra ~billion gates per chip for the memory (as that's just a co-packaged standard
22.
by dkfellows 8y ago
The brain definitely is able to use not just spiking frequency (which is approximately the same as EEG voltage, though not really) but also spiking patterns to encode information. We've observed some highly interesting phase locked loo
23.
by dkfellows 8y ago
FWIW, this is based on SpiNNaker, which is a system with a million CPU cores and a custom low-power multicast network backplane. It's possible to do simpler neural models with much less power than we do (and some of our competitors do
24.
by dkfellows 8y ago
We can do dynamic networking — the routing tables for the hardware is reloadable at runtime — but it's sufficiently difficult to do the routing computations that we only do that when the simulation is stopped at the moment. (We actuall
25.
by dkfellows 10y ago
The usual problem is to do with managing list construction, and the usual answer is the [list] command, which Does The Right Thing for sane code. We also made sure that such lists go through the script evaluation engine cleanly (except for
26.
by dkfellows 10y ago
Yes, that's at least technically possible. On the other hand, there's enough work that I believe it very unlikely that anything would be rejected like that provided it works well with the rest of the language, and is reasonably do
27.
by dkfellows 10y ago
Tcl has a bigger footprint than Lua, but provides more services.
28.
by dkfellows 10y ago
The string interconvertibility (more formally, strings are the supertype of all other value types) only really applies to values that you can regard as being immutable. Mutable state instead goes into a named entity (even if it is an automa
29.
by dkfellows 10y ago
If someone wants to use, say, LuaJIT to work on the $100k bounty for a 10x speedup of the Tcl language, they should go right ahead; prove that you can do it and claim the cash. (I guess I'll be rather involved in setting the test of th