in reply to Re: Re: "foreach" is to "next" as "map" is to ???
in thread "foreach" is to "next" as "map" is to ???

You make that look so *easy*...

Think about map, grep, and sort as operating on lists as a whole. That's what made the functional parts of Perl really click for me. for-loops operate on items that just happen to be bundled in lists. map and grep operate on lists that just happen to have items in them.

------
We are the carpenters and bricklayers of the Information Age.

Then there are Damian modules.... *sigh* ... that's not about being less-lazy -- that's about being on some really good drugs -- you know, there is no spoon. - flyingmoose

I shouldn't have to say this, but any code, unless otherwise stated, is untested

  • Comment on Re: Re: Re: "foreach" is to "next" as "map" is to ???

Replies are listed 'Best First'.
Re: Re: Re: Re: "foreach" is to "next" as "map" is to ???
by McMahon (Chaplain) on May 26, 2004 at 19:14 UTC
    Yeah, but my situation here was sort of like moving from middle-school straight to college.

    I'm pretty comfortable with looping, scalars and arrays, simple sorting, that sort of thing, but all of a sudden Sort array according to a value in each element? I needed some really heavy code.

    I have an aversion to using code that I don't understand, so I set out to understand the GRT, one chunk at a time.

    I learned a lot fast. Next to study is "the empty list technique"...
[reply]
      To help understand the empty list technique, look at this code, guess what it will output, and then try it. 
      my @a=((),(),());
printf "%d\n", scalar @a;

      [download]
      List flattening is the key. A little more directly: 
      printf "%d\n", scalar map {()} 1..3;

      [download]
      The PerlMonk tr/// Advocate
[reply]
[d/l]
[select]

In Section Seekers of Perl Wisdom