Re: Top 10 most common hard skills listed on resumes...

Bart <bc@freeuk.com> writes:

On 28/08/2024 15:57, Ben Bacarisse wrote:

Bart <bc@freeuk.com> writes:
 

On 28/08/2024 00:49, Ben Bacarisse wrote:

 

Indeed, and BLISS is not like that.  I had hoped to shed some light on
why there is some logic to BLISS's rather idiosyncratic design.
>

Given a declaration like 'int A' then:
>
                             BLISS   C
>
Read or write A's value   .A       A

I don't think that's right.  To change the value at address A (what I
think you mean by "write A's value") you write
    A = 42;
in BLISS.  And to add one to the value at address A you write
    A = .A + 1;

>
OK. That's just makes it more bizarre than I'd thought.

Curious.  It's what makes it consistent, though it is definitely an
uncommon approach.
 

The example I saw
included these lines:
>
     GETNUM(X);            ! returns a value via X
     Y = STEP(.X);
     PUTNUM(.Y)
>
So in an rvalue context:  X reads its address; while .X reads its
value.

The whole point is to remove the two contexts.  A variable name is
/always/ an lvalue (which is why it can be assigned).  C has an implicit
lvalue to rvalue conversion in the contexts you have come to expect it.
BLISS does not.  You always need a dot to convert to an rvalue.

>
This is the kind of thing I meant a few posts back. You don't need to take
A (which refers to some place where you can store values), and tell it to
fetch that value. Most HLLs will do that without being told.
>
(My point was that that was a distinguishing feature of HLLs, which is
missing in Forth for example.)

We are talking at cross purposes then.  I was not addressing anything
about your view of what makes an HLL.

But in an lvalue one:     Y writes its value; .Y may not be defined
>
It looks asymmetric. C like most languages is symmetric, you write 'A = A'
with the same syntax on both sides.

Since assignment is inherently asymmetric (you can't write 3 = A but you
can write A = 3) C's syntactic symmetry hides a semantic difference.
What is needed on the two sides is not the same.

>
I would argue that it is exactly the same.

How do you argue that, given that A=3 is allowed and 3=A is not?

...

I assume that in BLISS, A = A is legal, but does something odd like copy
A's address into itself.

What's odd about that?  And why call is a copy operation?  Do you think
of A = 42 as a copy operation?  BLISS is a low-level system language.

>
Why do you mean by call?

Typo.  I meant to write... And why call /it/ a copy-operation?  Do you
think of A = 42 as a copy operation?

--
Ben.