Raku By Example

## smart match

my $foo = 'bar';
say "match!" if $foo ~~ /bar/;       # Regex match
say "match!" if $foo ~~ "bar";       # String match
say "match!" if $foo ~~ Str;         # Class match
say "match!" if $foo ~~ :(Int, Str); # Signature match (destructure)


## hash match

my %lilei     ='Math'=>98,'Chinese'=>'72','English'=>'128';
my %hanmeimei ='Math'=>98,'Chinese'=>'72','English'=>'128';

say "they have the same course" if %lilei.keys ~~ %hanmeimei.keys;
say 'true' if %lilei{%hanmeimei.keys} ~~ %hanmeimei.values;

my $a = 2;
say so $a ~~ 1..3;
say so $a ~~ Int;
say so  $a ~~ 23;
say so $a ~~ {$_.Str ne $_.perl};
say so (1..3).ACCEPTS($a);

## 匹配哈希

    constant A = 100;
    constant B = 100;

    my (%powers, %count);

    # find bases which are powers of a preceeding root base
    # store decomposition into base and exponent relative to root
    for 2..Int(sqrt A) -> \a {
        next if a ~~ %powers;
        %powers{a, a**2, a**3 ...^ * > A} = a X=> 1..*;
    }

    # count duplicates
    for %powers.values -> \p {
        for 2..B -> \e {
            # raise to power \e
            # classify by root and relative exponent
            ++%count{p.key => p.value * e}
        }
    }

    # add +%count as one of the duplicates needs to be kept
    say (A - 1) * (B - 1) + %count - [+] %count.values;
Examples
