I was playing with sorting using a code reference, and found that I cannot obtain the code reference through a subroutine call without first storing the reference in a scalar.

EDIT 20060726 12:14 - Adding a summary at the top as I did not express my question clearly
It is permissible to sort using a scalar which holds a reference to a function, but it is an error to skip the step that stores the reference in a scalar. I wanted to know the distinction between the two. Good: 

my $sorter = \&some_function;
sort $sorter (1,2,3);

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Bad: 
sort \&some_function (1,2,3);

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It is also an error to obtain the coderef from a factory, without first storing the coderef in a scalar. 
 
sort make_sorter() (1,2,3)

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(Where make_sorter is a function that returns a coderef. The referenced sub being a valid sort function.)
End edit

Original example:

This code works as expected: 

use strict;
use warnings;

my $sorter = get_numeric();
my @sorted2 = sort $sorter (3,2,1);
print join(', ', @sorted2);

sub get_numeric {
    return \&numeric;
}

sub numeric($$) {
    my ($a,$b) = @_;
    $a <=> $b;
}

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This code does not work at all: 
use strict;
use warnings;

my @sorted2 = sort get_numeric() (3,2,1);
print join(', ', @sorted2);

sub get_numeric {
    return \&numeric;
}

sub numeric($$) {
    my ($a,$b) = @_;
    $a <=> $b;
}

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The error is: syntax error at pmsort line 4, near ") (" Is there a clean way to do this, or is the temporary storage in a scalar required?

Environment is perl 5.8.2 on openbsd.

In reply to Is it possible to sort using a coderef, without first storing the coderef in a scalar by imp

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