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#############################################################
## Perl Modules - Object::Pad
#############################################################

# New perl OO example (with an without defaults).
perl -MObject::Pad -E 'class Point { has $x :param = 0; has $y :param = 0; method move ($dX, $dY) { $x += $dX; $y += $dY } method describe {  say "A point at ($x,$y)" } } Point->new->describe'
A point at (0,0)
perl -MObject::Pad -E 'class Point { has $x :param = 0; has $y :param = 0; method move ($dX, $dY) { $x += $dX; $y += $dY } method describe {  say "A point at ($x,$y)" } } Point->new(x=>5, y=>6)->describe'
A point at (5,6)

# New perl OO example (BUILD phase, both)
perl -MObject::Pad -Mojo -E 'class My{ has $x :param; method Say { say "Say(): [@_] self=$self,x=$x"} BUILD { say "BUILD(): [@_]"; qw(x from_build) } sub BUILDARGS { say "BUILDARGS(): [@_]"; qw(x from_buildargs) }} my $s = My->new(x => "new_arg"); $s...
BUILDARGS(): [My x new_arg]
BUILD(): [x from_buildargs]
Say(): [say input] self=My=ARRAY(0xb400006faa2646b8),x=from_buildargs
bless( [
  "from_buildargs"
], 'My' )

# New perl OO example (BUILD phase,BUILDARGS)
perl -MObject::Pad -Mojo -E 'class My{ has $x :param; method Say { say "Say(): [@_] self=$self,x=$x"} sub BUILDARGS { say "BUILDARGS(): [@_]"; qw(x from_buildargs) }} my $s = My->new(x => "new_arg"); $s->Say("say input"); say r $s'
BUILDARGS(): [My x new_arg]
Say(): [say input] self=My=ARRAY(0xb4000077e98fd6d8),x=from_buildargs
bless( [
  "from_buildargs"
], 'My' )

# New perl OO example (BUILD phase,BUILD)
perl -MObject::Pad -Mojo -E 'class My{ has $x :param; method Say { say "Say(): [@_] self=$self,x=$x"} BUILD { say "BUILD(): [@_]"; qw(x from_build) } } my $s = My->new(x => "new_arg"); $s->Say("say input"); say r $s'                         BUILD(): ...
Say(): [say input] self=My=ARRAY(0xb4000079688b76d8),x=new_arg
bless( [
  "new_arg"
], 'My' )

# New perl OO example (BUILD ADJUST phases)
perl -MObject::Pad -Mojo -E 'class My{ has $x :param; method Say { say "Say(): [@_] self=$self,x=$x"} BUILD { say "BUILD(): [@_]"; qw(x from_build) } sub BUILDARGS { say "BUILDARGS(): [@_]"; qw(x from_buildargs) } ADJUST { say "ADJUST(): [@_] self=$s...
BUILD(): [x from_buildargs]
ADJUST(): [HASH(0xb4000076ffc351f8)] self=My=ARRAY(0xb4000076ffc266d8)
Say(): [say input] self=My=ARRAY(0xb4000076ffc266d8),x=from_buildargs
bless( [
  "from_buildargs"
], 'My' )

# New perl OO example (ADJUST strict phases)
perl -MObject::Pad -Mojo -E 'class My :strict(params) { has $x :param; method Say { say "Say(): [@_] self=$self,x=$x"} ADJUST { say "ADJUST(): [@_] self=$self"; qw(x from_adjust) } } my $s = My->new(x => "new_arg", x2 => 2 ); $s->Say("say input"); sa...
ADJUST(): [HASH(0xb400007a337fa2c0)] self=My=ARRAY(0xb400007a337e76b8)
Unrecognised parameters for My constructor: x2 at -e line 1.


#############################################################
## Perl Modules - overload
#############################################################

# Perl Modules - overload example code.
pod Set::Scalar::Base -e


#############################################################
## Perl Modules - PadWalker
#############################################################

# View the lexical variables in a scope.
perl -MPadWalker=peek_my -Mojo -E 'my $var=123; say r peek_my(0)'
{
  "\$var" => \123
}

# Call a method of an object obtained from peek_my
perl -MDevel::Peek -MPadWalker=peek_my -Mojo -E '{ package My; sub Func {"My-Func"} } my $var =  bless {}, "My"; my $obj_ref = peek_my(0)->{q($var)}; Dump $var; Dump $obj_ref; say $$obj_ref->Func'

# Update a lexical variable in a different scope.
my $lexicals = peek_my(1);
$lexicals->{'@arr'}->[1] = 4;


#############################################################
## Perl Modules - PadWalker::Eval
#############################################################

# Idea for a new module to run eval at a specific scope.
perl -E 'my $v=1; {package My; my $v=2; sub run_code { my ($code) = @_; my $v=3; eval $code }} my $v=4, say My::run_code(q($v))'

# PadWalker::Eval ideas.
sub eval ($string, $scope_level=0)


#############################################################
## Perl Modules - Parallel::ForkManager
#############################################################

# Simple exmplae of parallel processing
# (Perl Modules - Parallel::ForkManager)
# About 3 times slower than using threads!!!
perl -MParallel::ForkManager -E '
    my $pm = Parallel::ForkManager->new(30);
    for my $file (1..30) {
        $pm->start and next;
        say "Processing file $file";
        sleep(1);
        $pm->finish;
    }
    $pm->wait_all_children;
'


#############################################################
## Perl Modules - PerlIO
#############################################################

# View the encoding layers applied to a filehandle.
perl -E 'say for PerlIO::get_layers(*STDOUT)'
unix
perlio
perl -C -E 'say for PerlIO::get_layers(*STDOUT)'
unix
perlio
utf8
perl -CO -E 'say for PerlIO::get_layers(*STDOUT)'
unix
perlio
utf8


#############################################################
## Perl Modules - Pod::Usage
#############################################################

# Pull out a section from pod
perl -MPod::Usage=pod2usage -E "pod2usage(-input => `perldoc -l ojo`, -verbose => 99, -sections => '.*/x');"

# Pull out a sectin of perl documentation and store it in a variable
perl -MPod::Usage=pod2usage -E "open my $fh, '>', \my $out or die $!; pod2usage(-input => `perldoc -l ojo`, -verbose => 99, -sections => '.*/x', -output => $fh, exitval => 'NOEXIT'); say qq([$out])"


#############################################################
## Perl Modules - POSIX
#############################################################

# Perl Modules - POSIX
# exit vs _exit
# exit calls DESTROY, whereas, _exit does not:
perl -MPOSIX=_exit -E 'sub A::DESTROY { say "DEST" } my $v = bless {}, "A"; exit(0)'
DEST