in reply to Re^3: The Case for Macros in Perl
in thread The Case for Macros in Perl

Sure, right, but 
use MyFoo -macronic => <<'YO';
 ...
 YO;

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???

What is that meant to prove or disprove?

All you've succeeded in doing is pass a multi-line string as an argument to a modules import list.

A (trivial) example macro might look something like this:

use Macro ADD( x, y ) {
   x + y;
}

...

my $p = getPfromSomewhere();
my $q = getQfromSomewhere();
my $r = ADD( $p, $q );

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Which would substitute out as:

my $p = getPfromSomewhere();
my $q = getQfromSomewhere();
$r = $p + $q;

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And better yet:

use Macro ADD( x, y ) {
   x + y;
}

...

my $r = ADD( getPfromSomewhere(), getQfromSomewhere() );
...
my $s = ADD( geta(), getb() );

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Resulting in just:

my $r = getPfromSomewhere() + getQfromSomewhere();
my $s = geta() + getb();

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Allowing the efficient use of small "functions and methods" at the source level without the runtime overhead of the calls.

With the rise and rise of 'Social' network sites: 'Computers are making people easier to use everyday'
Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.
"Science is about questioning the status quo. Questioning authority".
In the absence of evidence, opinion is indistinguishable from prejudice.
functions and methods

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Re^5: The Case for Macros in Perl
by shmem (Chancellor) on Sep 15, 2014 at 06:52 UTC

    Way back, in perl4, there was (from perl.man) 

           -Idirectory
            may  be  used  in  conjunction  with -P to tell the C prep
+rocessor
            where to look for include  files.   By  default  /usr/incl
+ude  and
            /usr/lib/perl are searched.

       -P   causes your script to be run through  the  C  preprocessor
+  before
            compilation  by  perl.   (Since  both  comments and cpp di
+rectives
            begin with the # character, you  should  avoid  starting  
+comments
            with  any  words  recognized  by  the C preprocessor such 
+as "if",
            "else" or "define".)

    [download]
    which was dropped (in favour of source filters, I guess). But hey, you can still run your code through cpp: 
    #define ADD(x,y)  x + y

my $r = ADD( getPfromSomewhere(), getQfromSomewhere() );
...
my $s = ADD( geta(), getb() );

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    # 1 "macro.pl"
# 1 "<command-line>"
# 1 "/usr/include/stdc-predef.h" 1 3 4
# 30 "/usr/include/stdc-predef.h" 3 4
# 1 "/usr/include/x86_64-linux-gnu/bits/predefs.h" 1 3 4
# 31 "/usr/include/stdc-predef.h" 2 3 4
# 1 "<command-line>" 2
# 1 "macro.pl"


my $r = getPfromSomewhere() + getQfromSomewhere();
...
my $s = geta() + getb();

    [download]

    "can you tell me the way to Tipperary?" - "well, I wouldn't start from here..."
    ;-)

    perl -le'print map{pack c,($-++?1:13)+ord}split//,ESEL'
[reply]
[d/l]
[select]
      But hey, you can still run your code through cpp:

      True! But its a little like using a combine-harvester to trim your lawn. With extreme care it could be made to work, but there are lots of logistical problems and the potential for things to go very wrong.

      With the rise and rise of 'Social' network sites: 'Computers are making people easier to use everyday'
      Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.
      "Science is about questioning the status quo. Questioning authority".
      In the absence of evidence, opinion is indistinguishable from prejudice.
[reply]
Re^5: The Case for Macros in Perl
by Anonymous Monk on Sep 14, 2014 at 05:45 UTC

    What is that meant to prove or disprove?

    That eval doesn't have to be repeatedly called at runtime ... that you can have it at "compile time" ...

    not sure about "Macro" module but it looks like that macro pragma already provides this kind of thing, so what is missing? We have macros right?

[reply]
      From the docs:
      SEE ALSO macro::JA. macro::filter - macro.pm source filter backend

      With all that implies.

      With the rise and rise of 'Social' network sites: 'Computers are making people easier to use everyday'
      Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.
      "Science is about questioning the status quo. Questioning authority".
      In the absence of evidence, opinion is indistinguishable from prejudice.
[reply]

In Section Meditations