Module::Load(3p) | Perl Programmers Reference Guide | Module::Load(3p)

# NAME

Module::Load - runtime require of both modules and files

# SYNOPSIS

      use Module::Load;
      my $module = 'Data::Dumper';
      load Data::Dumper;     # loads that module, but not import any functions
                             # -> cannot use 'Dumper' function
      load 'Data::Dumper';   # ditto
      load $module           # tritto
      autoload Data::Dumper; # loads that module and imports the default functions
                             # -> can use 'Dumper' function
      my $script = 'some/script.pl'
      load $script;
      load 'some/script.pl';  # use quotes because of punctuations
      load thing;             # try 'thing' first, then 'thing.pm'
      load CGI, ':all';       # like 'use CGI qw[:standard]'

# DESCRIPTION

"Module::Load" eliminates the need to know whether you are trying to require either a file or a module.

If you consult "perldoc -f require" you will see that "require" will behave differently when given a bareword or a string.

In the case of a string, "require" assumes you are wanting to load a file. But in the case of a bareword, it assumes you mean a module.

This gives nasty overhead when you are trying to dynamically require modules at runtime, since you will need to change the module notation ("Acme::Comment") to a file notation fitting the particular platform you are on.

"Module::Load" eliminates the need for this overhead and will just DWYM.

## Difference between "load" and "autoload"

"Module::Load" imports the two functions - "load" and "autoload"

"autoload" imports the default functions automatically, but "load" do not import any functions.

"autoload" is usable under "BEGIN{};".

Both the functions can import the functions that are specified.

Following codes are same.

      load File::Spec::Functions, qw/splitpath/;
      autoload File::Spec::Functions, qw/splitpath/;

# FUNCTIONS

load
  Loads a specified module.

  See "Rules" for detailed loading rule.

autoload
  Loads a specified module and imports the default functions.

  Except importing the functions, 'autoload' is same as 'load'.

load_remote
  Loads a specified module to the specified package.

        use Module::Load 'load_remote';
        my $pkg = 'Other::Package';
        load_remote $pkg, 'Data::Dumper'; # load a module to 'Other::Package'
                                          # but do not import 'Dumper' function

  A module for loading must be quoted.

  Except specifing the package and quoting module name, 'load_remote' is same as 'load'.

autoload_remote
  Loads a specified module and imports the default functions to the specified package.

        use Module::Load 'autoload_remote';
        my $pkg = 'Other::Package';
        autoload_remote $pkg, 'Data::Dumper'; # load a module to 'Other::Package'
                                              # and imports 'Dumper' function

  A module for loading must be quoted.

  Except specifing the package and quoting module name, 'autoload_remote' is same as 'load_remote'.

# Rules

All functions have the following rules to decide what it thinks you want:

- If the argument has any characters in it other than those matching "\w", ":" or "'", it must be a file
- If the argument matches only "[\w:']", it must be a module
- If the argument matches only "\w", it could either be a module or a file. We will try to find "file.pm" first in @INC and if that fails, we will try to find "file" in @INC. If both fail, we die with the respective error messages.

# IMPORTS THE FUNCTIONS

'load' and 'autoload' are imported by default, but 'load_remote' and 'autoload_remote' are not imported.

To use 'load_remote' or 'autoload_remote', specify at 'use'.

"load","autoload","load_remote","autoload_remote"
  Imports the selected functions.

        # imports 'load' and 'autoload' (default)
        use Module::Load;
        # imports 'autoload' only
        use Module::Load 'autoload';
        # imports 'autoload' and 'autoload_remote', but don't import 'load';
        use Module::Load qw/autoload autoload_remote/;

'all'
  Imports all the functions.

        use Module::Load 'all'; # imports load, autoload, load_remote, autoload_remote

'','none',undef
  Not import any functions ("load" and "autoload" are not imported).

        use Module::Load '';
        use Module::Load 'none';
        use Module::Load undef;

# Caveats

Because of a bug in perl (#19213), at least in version 5.6.1, we have to hardcode the path separator for a require on Win32 to be "/", like on Unix rather than the Win32 "\". Otherwise perl will not read its own %INC accurately double load files if they are required again, or in the worst case, core dump.

"Module::Load" cannot do implicit imports, only explicit imports. (in other words, you always have to specify explicitly what you wish to import from a module, even if the functions are in that modules' @EXPORT)

# SEE ALSO

Module::Runtime provides functions for loading modules, checking the validity of a module name, converting a module name to partial ".pm" path, and related utility functions.

"require" in perlfunc <https://metacpan.org/pod/perlfunc#require> and "use" in perlfunc <https://metacpan.org/pod/perlfunc#use>.

Mojo::Loader is a "class loader and plugin framework", and is included in the Mojolicious <https://metacpan.org/release/Mojolicious> distribution.

Module::Loader is a module for finding and loading modules in a given namespace, inspired by "Mojo::Loader".

# ACKNOWLEDGEMENTS

Thanks to Jonas B. Nielsen for making explicit imports work.

# BUG REPORTS

Please report bugs or other issues to <bug-module-load@rt.cpan.org>.

# AUTHOR

This module by Jos Boumans <kane@cpan.org>.

# COPYRIGHT

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

2023-02-15 | perl v5.40.1