pairmap

Run a block for each pair and concatenate the results.

תקציר

my @out   = pairmap { BLOCK } @kvlist;
my $count = pairmap { BLOCK } @kvlist;   # scalar context

For every pair the block is called in list context with $a set to the key and $b set to the value; its results are appended to the output list in order.

מה מוחזר

In list context, the concatenation of everything every invocation of the block returned. In scalar context, the number of items that would have been returned in list context. $a and $b are aliased to the original list elements - modifications in the block are visible to the caller.

דוגמאות

my @lines = pairmap { "The key $a has value $b" } %hash;
my @flat  = pairmap { ( $a, uc $b ) } %h;   # values upper-cased
my @pairs = pairmap { [ $a, $b ] } %h;      # equivalent to `pairs`

הבדלים מן ה-upstream

Fully compatible with upstream.

ראו גם

• pairgrep - filter pairs by a predicate.

• pairfirst - stop at the first matching pair.

• pairs - bundle pairs into blessed arrayrefs.