λ式をPerlで表現するメモ

gistfile1.pl

#!/usr/bin/env perl -l
use strict;
use warnings;

# fx:=x+1;
sub f {
    local $_ = shift;
    $_+1;
}
print f(3);

# f:=^x.x+1;
my $f = sub {
    local $_ = shift;
    $_+1;
};
print $f->(3);

# f:^x y.x+y;
my $plus = sub {
    my($x, $y) = @_;
    $x + $y;
};
print $plus->(1,2);

# f:^x.(^y.x+y);
my $cplus = sub {
    my $x = shift;
    sub {
        my $y = shift;
        $x + $y;
    };
};
print $cplus->(1)->(2);