Re^2: interpolating operators within strings

Your insight is much appreciated! I was trying to do addition and subtraction of two lists of paired numbers and wanted to avoid separate loops.

Comment on Re^2: interpolating operators within strings

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Re^3: interpolating operators within strings by kcott (Archbishop) on Apr 14, 2013 at 04:01 UTC
Well, in that case, you might be better off with the `pairwise` function of List::MoreUtils: `$ perl -Mstrict -Mwarnings -E ' use List::MoreUtils qw{pairwise}; my @x = 0 .. 3; my @y = map { 10 + $_ } @x; say for pairwise { "$a + $b = " . ($a + $b) . "; $b - $a = " . ($b - $a) } @x, @y; ' 0 + 10 = 10; 10 - 0 = 10 1 + 11 = 12; 11 - 1 = 10 2 + 12 = 14; 12 - 2 = 10 3 + 13 = 16; 13 - 3 = 10` [download] Note how `$a` holds `@x` elements and `$b` holds `@y` elements. These (`$a` & `$b`) are the same special variables used by sort, so don't declare them; they're described in perlvar - SPECIAL VARIABLES - General Variables. You can use them in either order: cf. `$a + $b` and `$b - $a`. -- Ken	[reply] [d/l] [select]

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Re^3: interpolating operators within strings
by kcott (Archbishop) on Apr 14, 2013 at 04:01 UTC

Well, in that case, you might be better off with the pairwise function of List::MoreUtils:

$ perl -Mstrict -Mwarnings -E '
    use List::MoreUtils qw{pairwise};
    my @x = 0 .. 3;
    my @y = map { 10 + $_ } @x;
    say for pairwise {
        "$a + $b = " . ($a + $b) . "; $b - $a = " . ($b - $a)
    } @x, @y;
'
0 + 10 = 10; 10 - 0 = 10
1 + 11 = 12; 11 - 1 = 10
2 + 12 = 14; 12 - 2 = 10
3 + 13 = 16; 13 - 3 = 10
[download]

Note how $a holds @x elements and $b holds @y elements. These ($a & $b) are the same special variables used by sort, so don't declare them; they're described in perlvar - SPECIAL VARIABLES - General Variables. You can use them in either order: cf. $a + $b and $b - $a.

-- Ken

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