Other common macro idioms

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1.Other common macro [naming] idioms

On Mon, 04 Jun 2007 06:34:33 -0700, jmckitrick < XXXX@XXXXX.COM > said:

| The first two are obvious and common: WITH-FOO and DEF-FOO.  What are
| some other common idioms for abstractions where it is often
| advantageous to express them using macros?

  Just looking at standard Common Lisp names:

     * DOFOO and DO-FOO for iteration;
     * FOO-BIND for, well, binding;
     * FOOCASE and FOO-CASE for dispatch;
     (opening CLtL's index of macro names)
     * FOOF for place manipulation

  (by the way, I believe it would be either DEFFOO or DEFINE-FOO, but
  not DEF-FOO).

  ---Vassil.


-- 
The truly good code is the obviously correct code.

2.Shortening common idioms: bus assignment and 'prev' generation

Hello all,

In high level programming languages it's possible to shorten common
programming idioms by encapsulating them into functions / modules /
classes. It is similarly possible in simulation-aimed VHDL, but is much
more difficult in synthesis-aimed VHDL.

Here is one:

some_bus(31 downto 27) <= (others => '0');
some_bus(26) <= my_sig_3;
some_bus(25) <= my_sig_4;
some_bus(24 downto 20) <= (others => '0');
some_bus(19) <= my_sig_11;
some_bus(18 downto 2) <= (others => '0');
some_bus(1 downto 0) <= another_bus(1 downto 0);

I wish there sould be a way to just assign 'all zeros' to some_bus and
then the signals to relevant bits:

some_bus(31 downto 0) <= (others => '0');
some_bus(26) <= my_sig_3;
some_bus(25) <= my_sig_4;
some_bus(19) <= my_sig_11;
some_bus(1 downto 0) <= another_bus(1 downto 0);

This, unfortunately, doesn't work. Setting some_bus to 'L' also doesn't
work for synthesis (only simulation).

Another common idiom is seeing when a signal changed:

signal my_sig, my_sig_prev: std_logic;
...
...
process (clk, reset_n)
begin
  if reset_n = '0' then
    my_sig_prev <= '0';
  elsif rising_edge(clk) then
    my_sig_prev <= my_sig;
  end if;
end process;

And then:

some process:
...
  if rising_edge(clk) then
    if my_sig_prev /= my_sig then
     ...
...

How can this be shortened, in synthesis ? I find myself writing this or
similar code (checking for a rise, or fall, of my_sig, for instance, by
(my_sig = '0' and my_sig_prev = '1') for fall) too many times !

Eli

...

3.semi-urgent request for common-idioms

Does anyone have a reasonably current version of Brian Mastenbrook's
common-idioms package lying around that they'd be willing to email me
or put on a web server or something?

I have a bunch of software that depends on it, that I'm trying to
install on a new machine, and I can't seem to get it on the internet,
and all my copies are in the office which I can't get to today.

Cheers,

rif

4.SETF and MACRO idiom & archive wisdom...

Douglas Philips < XXXX@XXXXX.COM > writes:

> After numbing myself searching through decades of c.l.l archives, I'm
> not sure if in my stupor I've just passed over what I'm looking for,
> or if the needle I want is on a completely different farm from the
> haystacks I was looking in.
>
> Is there a way to write a SETF like thing, which does the evaluation
> of place only once, but which returns the _old_ value instead of the
> new? From what I unearthed about SETF (DEFUN (SETF FOO)) (DEF-SETF....
> PUSH isn't a SETy thing because it doesn't return the right thing, etc.
> ... that the answer is 'No'.

Look at DEFINE-SETF-EXPANDER.

5.[Clax86list] using common macros in NASM and C

On 25 Jul 2006 17:21:02 -0700
" XXXX@XXXXX.COM "  < XXXX@XXXXX.COM > wrote:

:Of course, the problem with the ".h"->".inc" translators is that they
:only work with a tiny subset of the stuff that normally appears in an
:.h file.

This may be true for specific translators which you have looked at, but my
experience is that the only thing which is particularly intractable is the
macro definitions.

-- Chuck

6. using common macros in NASM and C

7. Non-Lisp "macro" system closest to Common Lisp's?

8. in macro from ANSI Common Lisp