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.
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 siganture 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 occurence 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 = "XXX XX XXXXX XXXXXXX";
my $XXXX = "It's all Greek to me!";
sub fuenksshuen~ { ... }
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 MEeTAX"); # 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 <schwern@pobox.com>
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.