Raku By Example

my $range = 'a' .. 'f';
for $range.list -> $elem {
    say $elem;
}

.say for @( $range );
# .say for $list.list;
.say for $range.flat;

## 范围提取

# 给定一组排好序的数， 如果数字是连续的，就用 - 符号连接 头和尾
# 例如 -6, -3, -2, -1, 0, 1, 3, 4, 5, 7, 8, 9, 10, 11, 14, 15, 17, 18, 19, 20
# 处理后变为： -6,-3-1,3-5,7-11,14,15,17-20
# Task:编写一个函数， 将范围连接起来
#  0,  1,  2,  4,  6,  7,  8, 11, 12, 14,
#  15, 16, 17, 18, 19, 20, 21, 22, 23, 24,
#  25, 27, 28, 29, 30, 31, 32, 33, 35, 36,
#  37, 38, 39

sub range-extraction (*@ints) {
    my $prev = NaN;
    my @ranges;

    for @ints -> $int {
        if $int == $prev + 1 {
            @ranges[*-1].push: $int;
        }
        else {
            @ranges.push: [$int];
        }
        $prev = $int;
    }
    join ',', @ranges.map: -> @r { @r > 2 ?? "@r[0]-@r[*-1]" !! @r }
}

say range-extraction
    -6, -3, -2, -1, 0, 1, 3, 4, 5, 7, 8, 9, 10, 11, 14, 15, 17, 18, 19, 20;

say range-extraction
    0,  1,  2,  4,  6,  7,  8, 11, 12, 14,
    15, 16, 17, 18, 19, 20, 21, 22, 23, 24,
    25, 27, 28, 29, 30, 31, 32, 33, 35, 36,
    37, 38, 39;
Examples
