Search code examples
raku

TR/// : How do you apply TR to a string?

With tr///, I can do this:

my $str = 'xABCz';
$str ~~ tr:c/ABC//;

say "-->{$str}<--";

--output:--
-->ABC<--

But with TR///, which creates a new string, there doesn't seem to be a way to apply it directly to a string:

my $str = 'xABCz';
$str ~~ tr:c/ABC//;

my $new_str = $str ~~ TR:c:d/ABC//;
say "-->{$new_str}<--";

--output:--
-->True<--

I can use with to set $_ to $str:

my $str = 'xABCz';

with $str {   # now $_ refers to $str
    my $new_str = TR:c:d/ABC//;  # TR/// is called on $_.
    say "-->{$new_str}<--";
} 

--output:--
-->ABC<--

...or even:

my $str = 'xABCz';
my $new_str = TR:c:d/ABC// with $str;

say "-->{$new_str}<--";

--output:--
-->ABC<--

In perl, I would write:

my $str = 'xABCz';
my $new_str = $str =~ tr/ABC//rcd;  #r - new_string, c - complement, d - delete
say $new_str;

-output:--
ABC
Solution

  • Str.trans should have the same effect non-destructively.

    my $new_str = $str.trans("ABC" => "")