Bartosz about Chapel

[dsimcha]

On 11/10/2011 9:23 PM, Walter Bright wrote:
> On 11/10/2011 4:53 PM, bearophile wrote:
>> This is a (minor) wart of D. C# got this better, using the "sbyte" and
>> "ubyte" names. We have discussed this in past :-)
>
> Sorry, but I think this is meaningless trivia.
>
> There's been a lot of agonizing over names in D lately. They are a
> soul-sucking quagmire of wasting time.
>

Vote++.  Really bad names hurt, but there's no such thing as a perfect 
name.  Any name will be confusing in some context unless it's 
ridiculouslyVerboseAndWastesALotOfSpaceAndIsImpossibleToTypeOrRead. 
Even when names do get confusing, this can be solved by using static 
import for whatever module the most confusion is coming from.  (For 
example, due to its terse naming scheme I usually use static import for 
std.file.)  Typing the fully qualified name resolves any confusion.

>
>> When I program in D, I take care of keeping often in my mind that
>> "int" is
>> not an integer number, but a unchecked signed 2-complement
>> 32-bits-wide bit
>> field. Forgetting it causes several bugs and troubles.
>
> And when you program in floating point, you have to keep in mind the
> limitations of the exponent and the mantissa.
>
> And when you write a recursive function, you have to be mindful of stack
> limitations.
>
> There's no escaping what a computer is. In any engineering profession,
> you've got to keep in mind that your design becomes real parts made out
> of real materials, and those materials are far from ideal. Forget that
> at one's peril.

Interesting argument and I completely agree.  This illustrates a big 
difference between engineers/programmers/natural scientists and 
mathematicians/computer scientists:  The former view 
equations/theory/models as a convenient approximation of reality, to be 
abandoned when it's no longer useful, and view all abstractions as 
leaky.  To the latter, the theory/equations/models have a life of their own.

D is a language designed by an engineering mind (two if you count 
Andrei, who did his undergrad in EE but his Ph.D. in computer science), 
for engineering minds.  I also have an engineering/natural science 
background and very little formal comp sci or theoretical/abstract 
mathematics training, which might explain D's appeal to me.  Those that 
are into theoretical purity will unavoidably hate the language.  Those 
that care more about being able to abstract away exactly what they want 
to and nothing more will love it.

>
> ----
>
> This reminds me of the experience of a good friend of mine, very smart,
> who decided to learn Fortran by reading the DEC Fortran reference
> manual. He wrote his first program, and it worked perfectly the first
> time (did I say he was very smart?), except for one detail. It ran
> incredibly slowly.
>
> He poured over his listing and the manual, and could find nothing wrong.
> Finally, he took the listing (back in those days, we worked from paper
> listings) to my roommate and asked for help.
>
> My roommate looked at it and says, there's your problem. You are writing
> to a file by opening it, appending a single character, then closing it,
> in a loop. Don't you know you're supposed to open the file once, do all
> the writes, then close it?
>
> No, says my friend, the manual said nothing about that, although when
> you think about how the computer must work when writing a file, it is
> obvious.

Again, pretty insightful.  One of the conclusions I've come to in terms 
of pedagogy is that no amount of rote knowledge can ever substitute for 
having a good mental model of a system.  When I was an undergrad the 
biggest difference I noticed between the successful and unsuccessful 
students was that the successful ones would try to form a comprehensive 
mental model of the material, where the unsuccessful students would 
focus on rote memorizing facts and procedures.  Similarly, when I TA'd a 
course a couple years ago, I tried to encourage the professor to ask 
exam questions that were as hard as possible to get by rote (no canned 
procedure would work) but as easy as possible if you had a solid mental 
model of the material.