package Inline::Sub;
use strict;
use warnings;
use Filter::Simple;
use Regexp::Assemble;

FILTER {
    my %inline = extract_inlined_subs($_);
    my $re = build_sub_name_regex(\%inline);

    # Handle void call 
    while (m|^\s*($re)(\(.*\))\s*;\s*$|mg) {
        my ($sub, $args) = ($1, $2);
        my $replacement = build_void_sub(\%inline, $sub, $args);
        s|^\s*$sub\(.*\)\s*;\s*$|$replacement|mg;
    }

    # Handle assignment calls
    while (m|^\s*(.*?)\s*=\s*($re)(\(.*\))\s*;\s*$|mg) {
        my ($rhs, $sub, $args) = ($1, $2, $3);
        my $replacement = build_assignment_sub(\%inline, $sub, $rhs, $
+args);
        my $rhs_quoted = quotemeta $rhs;
        my $args_quoted = quotemeta $args;
        s|^\s*$rhs_quoted\s*=\s*$sub$args_quoted\s*;\s*$|$replacement|
+mg;
    }
};

sub build_void_sub {
    my ($inline, $sub, $args) = @_;
    my $uniq_label = '__' . $sub . '__' . int(rand 42);
    my $replacement = "$uniq_label:\n$inline->{$sub}";
    # Assignment to from @_
    $replacement =~ s|^(.*)=\s*\@_\s*;\s*$|$1= $args;|m if $replacemen
+t =~ m|^.*=\s*\@_\s*;\s*$|m;
    # Replace return
    $replacement =~ s|^(\s*)return.*;\s*$|$1last $uniq_label;|mg;
    return $replacement;
}

sub build_assignment_sub {
    my ($inline, $sub, $rhs, $args) = @_;
    my $uniq_label = '__' . $sub . '__' . int(rand 42);
    my $replacement = '';
    $replacement .= "$rhs;\n" if $rhs =~ m|^my|;
    $rhs =~ s|^my\s*||;
    $replacement .= "$uniq_label:\n$inline->{$sub}";
    # Assignment to from @_
    $replacement =~ s|^(.*)=\s*\@_\s*;\s*$|$1= $args;|m if $replacemen
+t =~ m|^.*=\s*\@_\s*;\s*$|m;
    # Replace return
    while ($replacement =~ m|^(\s*)return\s*(.*);\s*$|mg) {
        my ($leading_spaces, $return_value) = ($1, $2);
        $return_value = 'undef' if ! length($return_value);
        $replacement =~ s|^\s*return\s*.*;\s*$|$leading_spaces$rhs = $
+return_value;\n${leading_spaces}last $uniq_label;|m;
    }
    return $replacement;
}

sub extract_inlined_subs {
    my %inline;
    while ($_[0] =~ m|^inline sub (\w+)\s*({.*?^})|smg) {
        my ($sub, $body) = ($1, $2);
        $inline{$sub} = $body;
        $_[0] =~ s|^inline sub \w+.*?^}||sm;
    }
    return %inline;
}

sub build_sub_name_regex {
    my ($inline) = @_;
    my $ra = Regexp::Assemble->new;
    $ra->add($_) for keys %$inline;
    return $ra->re;
}
'This statement is false';
[download]

#!/usr/bin/perl
use strict;
use warnings;
use Inline::Sub;

my @list = 1 .. 100;

print time, "\n";
for (1 .. 5_000_000) {
    my $low = min(\@list);
    my $high = max(\@list);
    my $sum = sum(\@list);
    my $ave = $sum / @list;
    my $tot = @list;
    my $sd  = sd(\@list);
}
print time, "\n";

inline sub min {
    my ($list) = @_;
    my $min;
    for (@$list) {
        $min = $_ if ! defined $min || $_ < $min;
    }
    return $min;
}

inline sub max {
    my ($list) = @_;
    my $max;
    for (@$list) {
        $max = $_ if ! defined $max || $_ > $max;
    }
    return $max;
}

inline sub sum {
    my ($list) = @_;
    my $tot = 0;
    $tot += $_ for @$list;
    return $tot;
}

inline sub sd {
    my ($list) = @_;
    my $sum = sum($list);
    my $ave = $sum / @$list;
    my $num = 0;
    $num += (($_ - $ave) ** 2) for @$list;
    return sqrt($num / @$list);
}
[download]