Beefy Boxes and Bandwidth Generously Provided by pair Networks
"be consistent"
 
PerlMonks  

Comment on

( #3333=superdoc: print w/ replies, xml ) Need Help??

On the other hand, I'd also like to see a few examples of what people would use a macro facility for in Perl. Assuming that p5 had a C-like

#define name(arg[,arg]) {\ some code here\ }

I wouldn't use it for C-like purposes. C-like macros are not that powerful - you can only do basic textual substitutions. To quote Synopsis 6:

Macros (keyword: macro) are routines whose calls execute as soon as they are parsed (i.e. at compile-time). Macros may return another source code string or a parse-tree.

Returning a parse-tree is where it gets interesting. What we get here are LISPish macros. We'll be able to write code that's run at compile time to create our own syntax.

Want a switch statement in Perl6? Just write one.

Want to add AOP or Design by Contract support to Perl6? Just write some new syntax.

Want to create a domain-specific language so you can write code that more directly reflects the problem domain? Yes - you guessed it - just write some new syntax!

There's a discussion of macros on perl.perl6.language that you might find interesting. Also read the relevant bit of Apocalypse 6.

Macros - can't wait ;-)

Update: Just come across A Macro System for Perl?, which has some relevant material for those who are interested.


In reply to Re: Re: Macros, LFSPs and LFMs by adrianh
in thread Macros, LFSPs and LFMs by stefp

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post; it's "PerlMonks-approved HTML":



  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.
  • Log In?
    Username:
    Password:

    What's my password?
    Create A New User
    Chatterbox?
    and the web crawler heard nothing...

    How do I use this? | Other CB clients
    Other Users?
    Others having an uproarious good time at the Monastery: (5)
    As of 2015-07-06 00:23 GMT
    Sections?
    Information?
    Find Nodes?
    Leftovers?
      Voting Booth?

      The top three priorities of my open tasks are (in descending order of likelihood to be worked on) ...









      Results (68 votes), past polls