evalEmpire/perl5i

NAME

    perl5i - Fix as much of Perl 5 as possible in one pragma

SYNOPSIS

      use perl5i::2;
    
      or
    
      $ perl5i your_script.pl

DESCRIPTION

    Perl 5 has a lot of warts. There's a lot of individual modules and
    techniques out there to fix those warts. perl5i aims to pull the best
    of them together into one module so you can turn them on all at once.

    This includes adding features, changing existing core functions and
    changing defaults. It will likely not be 100% backwards compatible with
    Perl 5, though it will be 99%, perl5i will try to have a lexical
    effect.

    Please add to this imaginary world and help make it real, either by
    telling me what Perl looks like in your imagination
    (http://github.com/evalEmpire/perl5i/issues) or make a fork (forking on
    github is like a branch you control) and implement it yourself.

Rationale

    Changing perl 5 core is a slow and difficult process. Perl 5 aims to be
    compatible with ancient versions which means it is mostly stuck with
    design, decisions and defaults made way back in the 90's.

    There are modules in CPAN to solve or ease many of those issues but
    many people don't know about them or don't know which ones to use.

    Documentation and books are updated slowly and don't usually keep up;
    this information becomes some sort of community knowledge, invisible
    from the wider audience.

    Even if you know a solution, having to decide everytime which module to
    use and enable it individually might be enough for you to give up and
    just do things the old way.

    Perl5i brings all this community knowledge in a coherent way, in
    something like 'the best of CPAN', enabled with a single command.

    You don't need to know all it does nor how it does it, you just use
    perl5i::2 on your code and you automatically get a modern environment,
    with perl defaults, problems and inconsistencies fixed.

    You can refer beginers to perl5i and they can benefit from it without
    needing to become a perl guru first.

Using perl5i

    Because perl5i plans to be incompatible in the future, you do not
    simply use perl5i. You must declare which major version of perl5i you
    are using. You do this like so:

        # Use perl5i major version 2
        use perl5i::2;

    Thus the code you write with, for example, perl5i::2 will always remain
    compatible even as perl5i moves on.

    If you want to be daring, you can use perl5i::latest to get the latest
    version. This will automatically happen if the program is -e. This lets
    you do slightly less typing for one-liners like perl -Mperl5i -e ...

    If you want your module to depend on perl5i, you should depend on the
    versioned class. For example, depend on perl5i::2 and not perl5i.

    See "VERSIONING" for more information about perl5i's versioning scheme.

What it does

    perl5i enables each of these modules and adds/changes these functions.
    We'll provide a brief description here, but you should look at each of
    their documentation for full details.

 The Meta Object

    Every object (and everything is an object) now has a meta object
    associated with it. Using the meta object you can ask things about the
    object which were previously over complicated. For example...

        # the object's class
        my $class = $obj->mo->class;
    
        # its parent classes
        my @isa = $obj->mo->isa;
    
        # the complete inheritance hierarchy
        my @complete_isa = $obj->mo->linear_isa;
    
        # the reference type of the object
        my $reftype = $obj->mo->reftype;

    A meta object is used to avoid polluting the global method space. mo
    was chosen to avoid clashing with Moose's meta object.

    See perl5i::Meta for complete details.

 Subroutine and Method Signatures

    perl5i makes it easier to declare what parameters a subroutine takes.

        func hello($place) {
            say "Hello, $place!\n";
        }
    
        method get($key) {
            return $self->{$key};
        }
    
        method new($class: %args) {
            return bless \%args, $class;
        }

    func and method define subroutines as sub does, with some extra
    conveniences.

    The signature syntax is currently very simple. The content will be
    assigned from @_. This:

        func add($this, $that) {
            return $this + $that;
        }

    is equivalent to:

        sub add {
            my($this, $that) = @_;
            return $this + $that;
        }

    method defines a method. This is the same as a subroutine, but the
    first argument, the invocant, will be removed and made into $self.

        method get($key) {
            return $self->{$key};
        }
    
        sub get {
            my $self = shift;
            my($key) = @_;
            return $self->{$key};
        }

    Methods have a special bit of syntax. If the first item in the
    signature is $var: it will change the variable used to store the
    invocant.

        method new($class: %args) {
            return bless \%args, $class;
        }

    is equivalent to:

        sub new {
            my $class = shift;
            my %args = @_;
            return bless \%args, $class;
        }

    Anonymous functions and methods work, too.

        my $code = func($message) { say $message };

    Guarantees include:

      @_ will not be modified except by removing the invocant

    Future versions of perl5i will add to the signature syntax and
    capabilities. Planned expansions include:

      Signature validation
      Signature documentation
      Named parameters
      Required parameters
      Read only parameters
      Aliased parameters
      Anonymous method and function declaration
      Variable method and function names
      Parameter traits
      Traditional prototypes

    See http://github.com/evalEmpire/perl5i/issues/labels/syntax#issue/19
    for more details about future expansions.

    The equivalencies above should only be taken for illustrative purposes,
    they are not guaranteed to be literally equivalent.

    Note that while all parameters are optional by default, the number of
    parameters will eventually be enforced. For example, right now this
    will work:

        func add($this, $that) { return $this + $that }
    
        say add(1,2,3);  # says 3

    The extra argument is ignored. In future versions of perl5i this will
    be a runtime error.

  Signature Introspection

    The signature of a subroutine defined with func or method can be
    queried by calling the signature method on the code reference.

        func hello($greeting, $place) { say "$greeting, $place" }
    
        my $code = \&hello;
        say $code->signature->num_positional_params;  # prints 2

    Functions defined with sub will not have a signature.

    See perl5i::Signature for more details.

 Autoboxing

    autobox allows methods to be defined for and called on most unblessed
    variables. This means you can call methods on ordinary strings, lists
    and hashes! It also means perl5i can add a lot of functionality without
    polluting the global namespace.

    autobox::Core wraps a lot of Perl's built in functions so they can be
    called as methods on unblessed variables. @a->pop for example.

  alias

        $scalar_reference->alias( @identifiers );
        @alias->alias( @identifiers );
        %hash->alias( @identifiers );
        (\&code)->alias( @identifiers );

    Aliases a variable to a new global name.

        my $code = sub { 42 };
        $code->alias( "foo" );
        say foo();        # prints 42

    It will work on everything except scalar references.

        our %stuff;
        %other_hash->alias( "stuff" );  # %stuff now aliased to %other_hash

    It is not a copy, changes to one will change the other.

        my %things = (foo => 23);
        our %stuff;
        %things->alias( "stuff" );  # alias %things to %stuff
        $stuff{foo} = 42;           # change %stuff
        say $things{foo};           # and it will show up in %things

    Multiple @identifiers will be joined with '::' and used as the fully
    qualified name for the alias.

        my $class = "Some::Class";
        my $name  = "foo";
        sub { 99 }->alias( $class, $name );
        say Some::Class->foo;  # prints 99

    If there is just one @identifier and it has no "::" in it, the current
    caller will be prepended. $thing->alias("name") is shorthand for
    $thing->alias(CLASS, "name")

    Due to limitations in autobox, non-reference scalars cannot be aliased.
    Alias a scalar ref instead.

        my $thing = 23;
        $thing->alias("foo");  # error
    
        my $thing = \23;
        $thing->alias("foo");  # $foo is now aliased to $thing

    This is basically a nicer way to say:

        no strict 'refs';
        *{$package . '::'. $name} = $reference;

 Scalar Autoboxing

    All of the methods provided by autobox::Core are available from perl5i.

    in addition, perl5i adds some methods of its own.

  path

        my $object = $path->path;

    Creates a Path::Tiny $object for the given file or directory $path.

        my $path = "/foo/bar/baz.txt"->path;
        my $content = $path->slurp;

  center

        my $centered_string = $string->center($length);
        my $centered_string = $string->center($length, $character);

    Centers $string between $character. $centered_string will be of length
    $length.

    $character defaults to " ".

        say "Hello"->center(10);        # "   Hello  ";
        say "Hello"->center(10, '-');   # "---Hello--";

    center() will never truncate $string. If $length is less than
    $string->length it will just return $string.

        say "Hello"->center(4);        # "Hello";

  round

        my $rounded_number = $number->round;

    Round to the nearest integer.

  round_up

  ceil

        my $new_number = $number->round_up;

    Rounds the $number towards infinity.

        2.45->round_up;   # 3
      (-2.45)->round_up;  # -2

    ceil() is a synonym for round_up().

  round_down

  floor

        my $new_number = $number->round_down;

    Rounds the $number towards negative infinity.

        2.45->round_down;  # 2
      (-2.45)->round_down; # -3

    floor() is a synonyn for round_down().

  is_number

        $is_a_number = $thing->is_number;

    Returns true if $thing is a number understood by Perl.

        12.34->is_number;           # true
        "12.34"->is_number;         # also true
        "eleven"->is_number;        # false

  is_positive

        $is_positive = $thing->is_positive;

    Returns true if $thing is a positive number.

    0 is not positive.

  is_negative

        $is_negative = $thing->is_negative;

    Returns true if $thing is a negative number.

    0 is not negative.

  is_even

        $is_even = $thing->is_even;

    Returns true if $thing is an even integer.

  is_odd

        $is_odd = $thing->is_odd;

    Returns true if $thing is an odd integer.

  is_integer

        $is_an_integer = $thing->is_integer;

    Returns true if $thing is an integer.

        12->is_integer;             # true
        12.34->is_integer;          # false
        "eleven"->is_integer;       # false

  is_int

    A synonym for is_integer

  is_decimal

        $is_a_decimal_number = $thing->is_decimal;

    Returns true if $thing is a decimal number.

        12->is_decimal;             # false
        12.34->is_decimal;          # true
        ".34"->is_decimal;          # true
        "point five"->is_decimal;   # false

  require

        my $module = $module->require;

    Will require the given $module. This avoids funny things like eval
    qq[require $module] or die $@. It accepts only module names.

    On failure it will throw an exception, just like require. On a success
    it returns the $module. This is mostly useful so that you can
    immediately call $module's import method to emulate a use.

        # like "use $module qw(foo bar);" if that worked
        $module->require->import(qw(foo bar));
    
        # like "use $module;" if that worked
        $module->require->import;

  wrap

        my $wrapped = $string->wrap( width => $cols, separator => $sep );

    Wraps $string to width $cols, breaking lines at word boundries using
    separator $sep.

    If no width is given, $cols defaults to 76. Default line separator is
    the newline character "\n".

    See Text::Wrap for details.

  ltrim

  rtrim

  trim

        my $trimmed = $string->trim;
        my $trimmed = $string->trim($character_set);

    Trim whitespace. ltrim() trims off the start of the string (left),
    rtrim() off the end (right) and trim() off both the start and end.

        my $string = '    testme'->ltrim;        # 'testme'
        my $string = 'testme    '->rtrim;        # 'testme'
        my $string = '    testme    '->trim;     # 'testme'

    They all take an optional $character_set which will determine what
    characters should be trimmed. It follows regex character set syntax so
    A-Z will trim everything from A to Z. Defaults to \s, whitespace.

        my $string = '-> test <-'->trim('-><');  # ' test '   

  title_case

        my $name = 'joe smith'->title_case;   # Joe Smith

    Will uppercase every word character that follows a wordbreak character.

  path2module

        my $module = $path->path2module;

    Given a relative $path it will return the Perl module this represents.
    For example,

        "Foo/Bar.pm"->path2module;  # "Foo::Bar"

    It will throw an exception if given something which could not be a path
    to a Perl module.

  module2path

        my $path = $module->module2path;

    Will return the relative $path in which the Perl $module can be found.
    For example,

        "Foo::Bar"->module2path;  # "Foo/Bar.pm"

  is_module_name

        my $is_valid = $string->is_module_name;

    Will return true if the $string is a valid module name.

        "Foo::Bar"->is_module_name;  # true
        "Foo/Bar"->is_module_name;   # false

  group_digits

        my $number_grouped     = $number->group_digits;
        my $number_grouped     = $number->group_digits(\%options);

    Turns a number like 1234567 into a string like 1,234,567 known as
    "digit grouping".

    It honors your current locale to determine the separator and grouping.
    This can be overridden using %options.

    NOTE: many systems do not have their numeric locales set properly

    separator

      The character used to separate groups. Defaults to "thousands_sep" in
      your locale or "," if your locale doesn't specify.

    decimal_point

      The decimal point character. Defaults to "decimal_point" in your
      locale or "." if your locale does not specify.

    grouping

      How many numbers in a group? Defaults to "grouping" in your locale or
      3 if your locale doesn't specify.

      Note: we don't honor the full grouping locale, its a wee bit too
      complicated.

    currency

      If true, it will treat the number as currency and use the monetary
      locale settings. "mon_thousands_sep" instead of "thousands_sep" and
      "mon_grouping" instead of "grouping".

        1234->group_digits;                      # 1,234 (assuming US locale)
        1234->group_digits( separator => "." );  # 1.234

  commify

        my $number_grouped = $number->commify;
        my $number_grouped = $number->commify(\%options);

    commify() is just like group_digits() but it is not locale aware. It is
    useful when you want a predictable result regardless of the user's
    locale settings.

    %options defaults to ( separator => ",", grouping => 3, decimal_point
    => "." ). Each key will be overridden individually.

        1234->commify;                      # 1,234
        1234->commify({ separator => "." });  # 1.234

  reverse

        my $reverse = $string->reverse;

    Reverses a $string.

    Unlike Perl's reverse(), this always reverses the string regardless of
    context.

 Array Autoboxing

    The methods provided by "Array Methods" in autobox::Core are available
    from perl5i.

    All the functions from List::Util and select ones from List::MoreUtils
    are all available as methods on unblessed arrays and array refs: first,
    max, maxstr, min, minstr, minmax, shuffle, reduce, sum, any, all, none,
    true, false, uniq and mesh.

    They have all been altered to return array refs where applicable in
    order to allow chaining.

        @array->grep(sub{ $_->is_number })->sum->say;

  foreach

        @array->foreach( func($item) { ... } );

    Works like the built in foreach, calls the code block for each element
    of @array passing it into the block.

        @array->foreach( func($item) { say $item } );  # print each item

    It will pass in as many elements as the code block accepts. This allows
    you to iterate through an array 2 at a time, or 3 or 4 or whatever.

        my @names = ("Joe", "Smith", "Jim", "Dandy", "Jane", "Lane");
        @names->foreach( func($fname, $lname) {
            say "Person: $fname $lname";
        });

    A normal subroutine with no signature will get one at a time.

    If @array is not a multiple of the iteration (for example, @array has 5
    elements and you ask 2 at a time) the behavior is currently undefined.

  as_hash

        my %hash = @array->as_hash;

    This method returns a %hash where each element of @array is a key. The
    values are all true. Its functionality is similar to:

        my %hash = map { $_ => 1 } @array;

    Example usage:

        my @array = ("a", "b", "c");
        my %hash = @array->as_hash;
        say q[@array contains 'a'] if $hash{"a"};

  pick

        my @rand = @array->pick($number);

    The pick() method returns a list of $number elements in @array. If
    $number is larger than the size of the list, it returns the entire list
    shuffled.

    Example usage:

        my @array = (1, 2, 3, 4);
        my @rand = @array->pick(2);

  pick_one

        my $rand = @array->pick_one;

    The pick_one() method returns a random element in @array. It is similar
    to @array->pick(1), except that it does not return a list.

    Example usage:

        my @array = (1,2,3,4);
        my $rand = @array->pick_one;

  diff

    Calculate the difference between two (or more) arrays:

        my @a = ( 1, 2, 3 );
        my @b = ( 3, 4, 5 );
    
        my @diff_a = @a->diff(\@b) # [ 1, 2 ]
        my @diff_b = @b->diff(\@a) # [ 4, 5 ]

    Diff returns all elements in array @a that are not present in array @b.
    Item order is not considered: two identical elements in both arrays
    will be recognized as such disregarding their index.

        [ qw( foo bar ) ]->diff( [ qw( bar foo ) ] ) # empty, they are equal

    For comparing more than two arrays:

        @a->diff(\@b, \@c, ... )

    All comparisons are against the base array (@a in this example). The
    result will be composed of all those elements that were present in @a
    and in none other.

    It also works with nested data structures; it will traverse them
    depth-first to assess whether they are identical or not. For instance:

        [ [ 'foo ' ], { bar => 1 } ]->diff([ 'foo' ]) # [ { bar => 1 } ]

    In the case of overloaded objects (i.e., DateTime, URI, Path::Class,
    etc.), it tries its best to treat them as strings or numbers.

        my $uri  = URI->new("http://www.perl.com");
        my $uri2 = URI->new("http://www.perl.com");
    
        [ $uri ]->diff( [ "http://www.perl.com" ] ); # empty, they are equal
        [ $uri ]->diff( [ $uri2 ] );                 # empty, they are equal

  popn

        my @newarray = @array->popn($n);

    Pops $n values from the @array.

    If $n is greater than the length of @array, it will return the whole
    @array. If $n is 0, it will return an empty array.

    A negative $n or non-integer is an error.

        my @array = (1, 2, 3, 4, 5);
        my @newarray = @array->popn(3); # (3, 4, 5)

  shiftn

           my @newarray = @array->shiftn($n);

    Works like popn, but it shifts off the front of the array instead of
    popping off the end.

        my @array = (1, 2, 3, 4, 5);
        my @newarray = @array->shiftn(3); # (1, 2, 3)

  intersect

        my @a = (1 .. 10);
        my @b = (5 .. 15);
    
        my @intersection = @a->intersect(\@b) # [ 5 .. 10 ];

    Performs intersection between arrays, returning those elements that are
    present in all of the argument arrays simultaneously.

    As with diff(), it works with any number of arrays, nested data
    structures of arbitrary depth, and handles overloaded objects
    graciously.

  ltrim

  rtrim

  trim

        my @trimmed = @list->trim;
        my @trimmed = @list->trim($character_set);

    Trim whitespace from each element of an array. Each works just like
    their scalar counterpart.

        my @trimmed = [ '   foo', 'bar   ' ]->ltrim;  # [ 'foo', 'bar   ' ]
        my @trimmed = [ '   foo', 'bar   ' ]->rtrim;  # [ '   foo', 'bar' ]
        my @trimmed = [ '   foo', 'bar   ' ]->trim;   # [ 'foo', 'bar'    ]

    As with the scalar trim() methods, they all take an optional
    $character_set which will determine what characters should be trimmed.

        my @trimmed = ['-> foo <-', '-> bar <-']->trim('-><'); # [' foo ', ' bar ']

 Hash Autoboxing

    All of the methods provided by "Hash Methods" in autobox::Core are
    available from perl5i.

    In addition...

  each

    Iterate through each key/value pair in a hash using a callback.

        my %things = ( foo => 23, bar => 42 );
        %things->each( func($k, $v) {
            say "Key: $k, Value: $v"
        });

    Unlike the each function, individual calls to each are guaranteed to
    iterate through the entirety of the hash.

  flip

    Exchanges values for keys in a hash.

        my %things = ( foo => 1, bar => 2, baz => 5 );
        my %flipped = %things->flip; # { 1 => foo, 2 => bar, 5 => baz }

    If there is more than one occurrence of a certain value, any one of the
    keys may end up as the value. This is because of the random ordering of
    hash keys.

        # Could be { 1 => foo }, { 1 => bar }, or { 1 => baz }
        { foo => 1, bar => 1, baz => 1 }->flip;

    Because hash references cannot usefully be keys, it will not work on
    nested hashes.

        { foo => [ 'bar', 'baz' ] }->flip; # dies

  merge

    Recursively merge two or more hashes together using
    Hash::Merge::Simple.

        my $a = { a => 1 };
        my $b = { b => 2, c => 3 };
    
        $a->merge($b); # { a => 1, b => 2, c => 3 }

    For conflicting keys, rightmost precedence is used:

        my $a = { a => 1 };
        my $b = { a => 100, b => 2};
    
        $a->merge($b); # { a => 100, b => 2 }
        $b->merge($a); # { a => 1,   b => 2 }

    It also works with nested hashes, although it won't attempt to merge
    array references or objects. For more information, look at the
    Hash::Merge::Simple docs.

  diff

        my %staff    = ( bob => 42, martha => 35, timmy => 23 );
        my %promoted = ( timmy => 23 );
    
        %staff->diff(\%promoted); # { bob => 42, martha => 35 }

    Returns the key/value pairs present in the first hash that are not
    present in the subsequent hash arguments. Otherwise works as
    @array->diff.

  intersect

        %staff->intersect(\%promoted); # { timmy => 23 }

    Returns the key/value pairs that are present simultaneously in all the
    hash arguments. Otherwise works as @array->intersect.

 Code autoboxing

  signature

        my $sig = $code->signature;

    You can query the signature of any code reference defined with func or
    method. See "Signature Introspection" for details.

    If $code has a signature, returns an object representing $code's
    signature. See perl5i::Signature for details. Otherwise it returns
    nothing.

  caller

    Perl6::Caller causes caller to return an object in scalar context.

  die

    die now always returns an exit code of 255 instead of trying to use $!
    or $? which makes the exit code unpredictable. If you want to exit with
    a message and a special exit code, use warn then exit.

  list

    list will force list context similar to how scalar will force scalar
    context.

 utf8::all

    perl5i turns on utf8::all which turns on all the Unicode features of
    Perl it can.

    Here is the current list, more may be turned on later.

    Bare strings in your source code are now UTF8. This means UTF8 variable
    and method names, strings and regexes.

        my $message = "انا لا اتكلم العربيه";
        my $τάδε    = "It's all Greek to me!";
        sub fünkßhüñ { ... }

    Strings will be treated as a set of characters rather than a set of
    bytes. For example, length will return the number of characters, not
    the number of bytes.

        length("perl5i is MËTÁŁ");  # 15, not 18

    @ARGV will be read as UTF8.

    STDOUT, STDIN, STDERR and all newly opened filehandles will have UTF8
    encoding turned on. Consequently, if you want to output raw bytes to a
    file, such as outputting an image, you must set binmode $fh.

  capture

        my($stdout, $stderr) = capture { ... } %options;
        my $stdout = capture { ... } %options;

    capture() lets you capture all output to STDOUT and STDERR in any block
    of code.

        # $out = "Hello"
        # $err = "Bye"
        my($out, $err) = capture {
            print "Hello";
            print STDERR "Bye";
        };

    If called in scalar context, it will only return STDOUT and silence
    STDERR.

        # $out = "Hello"
        my $out = capture {
            print "Hello";
            warn "oh god";
        };

    capture takes some options.

    tee

      tee will cause output to be captured yet still printed.

          my $out = capture { print "Hi" } tee => 1;

    merge

      merge will merge STDOUT and STDERR into one variable.

          # $out = "HiBye"
          my $out = capture {
              print "Hi";
              print STDERR "Bye";
          } merge => 1;

 Carp

    croak and carp from Carp are always available.

    The Carp message will always format consistently, smoothing over the
    backwards incompatible change in Carp 1.25.

 Child

    Child provides the child function which is a better way to do forking.

    child creates and starts a child process, and returns an
    Child::Link::Proc object which is a better interface for managing the
    child process. The only required argument is a codeblock, which is
    called in the new process. exit() is automatically called for you after
    the codeblock returns.

        my $proc = child {
            my $parent = shift;
            ...
        };

    You can also request a pipe for IPC:

        my $proc = child {
            my $parent = shift;
    
            $parent->say("Message");
            my $reply = $parent->read();
    
            ...
        } pipe => 1;
    
        my $message = $proc->read();
        $proc->say("reply");

    See Child for more information.

 English

    English gives English names to the punctuation variables; for instance,
    <$@> is also <$EVAL_ERROR>. See perlvar for details.

    It does not load the regex variables which affect performance.
    $PREMATCH, $MATCH, and $POSTMATCH will not exist. See the p modifier in
    perlre for a better alternative.

 Modern::Perl

    Modern::Perl turns on strict and warnings, enables all the 5.10
    features like given/when, say and state, and enables C3 method
    resolution order.

 CLASS

    Provides CLASS and $CLASS alternatives to __PACKAGE__.

 File::chdir

    File::chdir gives you $CWD representing the current working directory
    and it's assignable to chdir. You can also localize it to safely chdir
    inside a scope.

 File::stat

    File::stat causes stat to return an object in scalar context.

 DateTime

    time, localtime, and gmtime are replaced with DateTime objects. They
    will all act like the core functions.

        # Sat Jan 10 13:37:04 2004
        say scalar gmtime(2**30);
    
        # 2004
        say gmtime(2**30)->year;
    
        # 2009 (when this was written)
        say time->year;

 Time::y2038

    gmtime() and localtime() will now safely work with dates beyond the
    year 2038 and before 1901. The exact range is not defined, but we
    guarantee at least up to 2**47 and back to year 1.

 IO::Handle

    Turns filehandles into objects so you can call methods on them. The
    biggest one is autoflush rather than mucking around with $| and select.

        $fh->autoflush(1);

 autodie

    autodie causes system and file calls which can fail (open, system, and
    chdir, for example) to die when they fail. This means you don't have to
    put or die at the end of every system call, but you do have to wrap it
    in an eval block if you want to trap the failure.

    autodie's default error messages are pretty smart.

    All of autodie will be turned on.

 autovivification

    autovivification fixes the bug/feature where this:

        $hash = {};
        $hash->{key1}{key2};

    Results in $hash->{key1} coming into existence. That will no longer
    happen.

 No indirect object syntax

    perl5i turns indirect object syntax, ie. new $obj, into a compile time
    error. Indirect object syntax is largely unnecessary and removing it
    avoids a number of ambiguous cases where Perl will mistakenly try to
    turn a function call into an indirect method call.

    See indirect for details.

  want

    want() generalizes the mechanism of the wantarray function, allowing a
    function to determine the context it's being called in. Want
    distinguishes not just scalar v. array context, but void, lvalue,
    rvalue, boolean, reference context, and more. See perldoc Want for full
    details.

 Try::Tiny

    Try::Tiny gives support for try/catch blocks as an alternative to eval
    BLOCK. This allows correct error handling with proper localization of
    $@ and a nice syntax layer:

            # handle errors with a catch handler
            try {
                    die "foo";
            } catch {
                    warn "caught error: $_";
            };
    
            # just silence errors
            try {
                    die "foo";
            };

    See perldoc Try::Tiny for details.

 true

    You no longer have to put a true value at the end of a module which
    uses perl5i.

 Better load errors

    Most of us have learned the meaning of the dreaded "Can't locate Foo.pm
    in @INC". Admittedly though, it's not the most helpful of the error
    messages. In perl5i we provide a much friendlier error message.

    Example:

        Can't locate My/Module.pm in your Perl library.  You may need to install it
        from CPAN or another repository.  Your library paths are:
            Indented list of paths, 1 per line...

Turning off features

        use perl5i::2 -skip => \@features_to_skip;

    While perl5i is intended as a curated collection of modules, its
    possible you might not want certain features. Features can be turned
    off in your scope by using -skip.

    For example, this will skip loading Try::Tiny.

        use perl5i::latest -skip => [qw(Try::Tiny)];

    Why would you do this? You might want to use a different try/catch
    module such as TryCatch which provides its own try and catch.

    The feature strings are: autobox, autodie, autovivification, capture,
    Carp::Fix::1_25, Child, CLASS, die, English, File::chdir, indirect,
    list, Meta, Modern::Perl, Perl6::Caller, Signatures, stat, time, true,
    Try::Tiny, utf8::all, Want.

Command line program

    There is a perl5i command line program installed with perl5i (Windows
    users get perl5i.bat). This is handy for writing one liners.

        perl5i -e 'gmtime->year->say'

    And you can use it on the #! line.

        #!/usr/bin/perl5i
    
        gmtime->year->say;

    If you write a one-liner without using this program, saying -Mperl5i
    means -Mperl5i::latest. Please see "Using perl5i" and "VERSIONING" for
    details.

BUGS

    Some parts are not lexical. Some parts are package scoped.

    If you're going to use two versions of perl5i together, we do not
    currently recommend having them in the same package.

    See http://github.com/evalEmpire/perl5i/issues/labels/bug for a
    complete list.

    Please report bugs at http://github.com/evalEmpire/perl5i/issues/.

VERSIONING

    perl5i follows the Semantic Versioning policy, http://semver.org. In
    short...

    Versions will be of the form X.Y.Z.

    0.Y.Z may change anything at any time.

    Incrementing X (ie. 1.2.3 -> 2.0.0) indicates a backwards incompatible
    change.

    Incrementing Y (ie. 1.2.3 -> 1.3.0) indicates a new feature.

    Incrementing Z (ie. 1.2.3 -> 1.2.4) indicates a bug fix or other
    internal change.

NOTES

    Inspired by chromatic's Modern::Perl and in particular
    http://www.modernperlbooks.com/mt/2009/04/ugly-perl-a-lesson-in-the-importance-of-language-design.html.

    I totally didn't come up with the "Perl 5 + i" joke. I think it was
    Damian Conway.

THANKS

    Thanks to our contributors: Chas Owens, Darian Patrick, rjbs,
    chromatic, Ben Hengst, Bruno Vecchi and anyone else I've forgotten.

    Thanks to Flavian and Matt Trout for their signature and Devel::Declare
    work.

    Thanks to all the CPAN authors upon whom this builds.

LICENSE

    Copyright 2009-2010, Michael G Schwern <[email protected]>

    This program is free software; you can redistribute it and/or modify it
    under the same terms as Perl itself.

    See http://dev.perl.org/licenses/artistic.html

SEE ALSO

    Repository: http://github.com/evalEmpire/perl5i/ Issues/Bugs:
    http://github.com/evalEmpire/perl5i/issues IRC: irc://irc.perl.org on
    the #perl5i channel Wiki: http://github.com/evalEmpire/perl5i/wiki
    Twitter: http://twitter.com/perl5i

    Frequently Asked Questions about perl5i: perl5ifaq

    Some modules with similar purposes include: Modern::Perl, Common::Sense

    For a complete object declaration system, see Moose and
    MooseX::Declare.